Search

The introduction of exotic species has a major impact on a wide range of ecosystems, especially in aquatic ecosystems. Trichocorixa v. verticalis (Fieber, 1851), an euryhaline aquatic hemipteran native North America, has occurred as an exotic species in the Iberian Peninsula since at least 1997. In this study, we compared several physiological and biological traits (salinity tolerance of the different developmental stages, thermal tolerance, fecundity, and dispersal ability) in the alien species and three native, syntopic corixidae species (Sigara lateralis, Sigara scripta, and Sigara selecta), to determine which traits may explain its invasion success. Trichocorixa verticalis was the species most resistant to high conductivity at the egg stage, while S. selecta showed the highest halotolerance as adults. The invader had the highest upper thermal limit and a much higher fecundity than Sigara species. Wing morphometry suggested that T. verticalis may be a stronger flier than the native species. Our findings provide an example of how functional and ecological niche interactions among alien and native species can help predict impacts of invasion on aquatic communities.

Biological invasions have become one of the most important drivers of biodiversity loss and ecosystem change world-wide. However, it is still unclear how invasions may interact with local abiotic stressors, which are expected to increase as global change intensifies. Furthermore, we know little about the response to biological invasions of insects, despite their disproportionate contribution to global animal biodiversity. The aim of the present work is to investigate the impact of an invasive aquatic insect on the co-occurrence patterns of native species of insects along a salinity gradient, and determine which assembly rules are driving these patterns. First, we characterised the habitat specialisation and functional niches of each species from physiological and biological traits, respectively, and their degree of overlap. Second, we used field data to compare the co-occurrence patterns of native and invasive species in invaded and non-invaded areas of southern Iberia and northern Morocco. Finally, we tested if habitat filtering or niche differentiation assembly rules mediate their co-occurrence. In non-invaded areas, habitat filtering drives habitat segregation of species along the salinity gradient, with a lower contribution of niche differentiation. The presence of the invasive insect modifies the distribution and co-occurrence patterns of native species. In invaded areas, niche differentiation seems to be the main mechanism to avoid competition among the invasive and native species, enabling coexistence and resource partitioning. The combined study of functional niche similarity and abiotic stressor tolerance of invasive and native species can improve our understanding of the effects of invasive species along abiotic stress gradients. This approach may increase our capacity to predict the outcomes of biological invasion in a global change context. A lay summary is available for this article., This work was partially supported by funding from a predoctoral FPU grant to J.A.C.. C.C. was supported in part by a JAE predoctoral grant from CSIC and by the postdoctoral grant 3160330 from FONDECYT. C.G.‐C. was supported by the MARS project (Managing Aquatic ecosystems and water Resources under multiple Stress), funded by the European Union under the 7th Framework Programme (contract no. 603378). This work was also supported by the projects P10‐RNM‐6262 (A.J.G.) (Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía), ‘Atlas de los coleópteros acuáticos de España peninsular’ (A.M.) (Ministerio de Agricultura, Alimentación y Medio Ambiente) and CGL2013‐48950‐C2‐2‐P (J.V.) (Ministerio de Economía y Competitividad).

Hydrocarbons are the principal component of insects cuticle and play an important role in maintaining water balance. Cuticular impermeability could be an adaptative response to salinity and desiccation in aquatic insects; however, cuticular hydrocarbons have been poorly explored in this group and there are no previous data on saline species. We characterized cuticular hydrocarbons of adults and larvae of two saline aquatic beetles, namely Nebrioporus baeticus (Dytiscidae) and Enochrus jesusarribasi (Hydrophilidae), using a gas chromatograph coupled to a mass spectrometer. The CHC profile of adults of both species, characterized by a high abundance of branched alkanes and low of unsaturated alkenes, seems to be more similar to that of some terrestrial beetles (e.g. desert Tenebrionidae) compared with other aquatic Coleoptera (freshwater Dytiscidae). Adults of E. jesusarribasi had longer chain compounds than N. baeticus, in agreement with their higher resistance to salinity and desiccation. The more permeable cuticle of larvae was characterized by a lower diversity in compounds, shorter carbon chain length and a higher proportion of unsaturated hydrocarbons compared with that of the adults. These results suggest that osmotic stress on aquatic insects could exert a selection pressure on CHC profile similar to aridity in terrestrial species.

© 2017. Published by The Company of Biologists Ltd, Exposing organisms to a particular stressor may enhance tolerance to a subsequent stress, when protective mechanisms against the two stressors are shared. Such cross-tolerance is a common adaptive response in dynamic multivariate environments and often indicates potential co-evolution of stress traits. Many aquatic insects in inland saline waters from Mediterranean-climate regions are sequentially challenged with salinity and desiccation stress. Thus, cross-tolerance to these physiologically similar stressors could have been positively selected in insects of these regions. We used adults of the saline water beetles Enochrus jesusarribasi (Hydrophilidae) and Nebrioporus baeticus (Dytiscidae) to test cross-tolerance responses to desiccation and salinity. In independent laboratory experiments, we evaluated the effects of (i) salinity stress on the subsequent resistance to desiccation and (ii) desiccation stress (rapid and slow dehydration) on the subsequent tolerance to salinity. Survival, water loss and haemolymph osmolality were measured. Exposure to stressful salinity improved water control under subsequent desiccation stress in both species, with a clear cross-tolerance (enhanced performance) in N. baeticus. In contrast, general negative effects on performance were found under the inverse stress sequence. The rapid and slow dehydration produced different water loss and haemolymph osmolality dynamics that were reflected in different survival patterns. Our finding of cross-tolerance to salinity and desiccation in ecologically similar species from distant lineages, together with parallel responses between salinity and thermal stress previously found in several aquatic taxa, highlights the central role of adaption to salinity and co-occurring stressors in arid inland waters, having important implications for the species' persistence under climate change., This research was funded by the I+D+i project CGL2013-48950-C2-2-P [Ministerio de Economıa y Competitividad cofinanced with FEDER (Fonds Europe ́ ́en de Développement Économique et Régional) funds], a PhD grant from Universidad de Murcia to S.P. and two post-doctoral grants from the Royal Society UK (Newton International Program) and from Ministerio de Economıa y Competitividad (Juan de ́la Cierva Formación Program) to P.A.

Macroinvertebrate samples collected during spring-summer 2013 in high mountain rivers of the Ordesa and Monte Perdido National Park (Pyrenees) contained several Hydraena species (Coleoptera: Hydraenidae) where we found two genera of suctorian ciliates as epibionts: Tokophrya and Discophrya. The individuals of the genus Tokophrya probably belong to species Tokophrya stenostyla, being the first time that this species is observed attached on arthropods. Suctorians of the genus Discophrya were identified as a new species called Discophrya ordesae sp. n. The presence and abundance of epibionts was discussed in the frame of the biological and ecological characteristics of the species of Hydraena where they were found.

Transitions from fresh to saline habitats are restricted to a handful of insect lineages, as the colonization of saline waters requires specialized mechanisms to deal with osmotic stress. Previous studies have suggested that tolerance to salinity and desiccation could be mechanistically and evolutionarily linked, but the temporal sequence of these adaptations is not well established for individual lineages. We combined molecular, physiological and ecological data to explore the evolution of desiccation resistance, hyporegulation ability (i.e., the ability to osmoregulate in hyperosmotic media) and habitat transitions in the water beetle genus Enochrus subgenus Lumetus (Hydrophilidae). We tested whether enhanced desiccation resistance evolved before increases in hyporegulation ability or vice versa, or whether the two mechanisms evolved in parallel. The most recent ancestor of Lumetus was inferred to have high desiccation resistance and moderate hyporegulation ability. There were repeated shifts between habitats with differing levels of salinity in the radiation of the group, those to the most saline habitats generally occurring more rapidly than those to less saline ones. Significant and accelerated changes in hyporegulation ability evolved in parallel with smaller and more progressive increases in desiccation resistance across the phylogeny, associated with the colonization of meso‐ and hypersaline waters during global aridification events. All species with high hyporegulation ability were also desiccation‐resistant, but not vice versa. Overall, results are consistent with the hypothesis that desiccation resistance mechanisms evolved first and provided the physiological basis for the development of hyporegulation ability, allowing these insects to colonize and diversify across meso‐ and hypersaline habitats., This work was funded by the I+D+i project CGL2013‐48950‐C2‐1&2‐P (AEI/FEDER, UE), a predoctoral grant and a scholarship grant from the University of Murcia to S. Pallarés and two postdoctoral grants from the Royal Society UK (Newton International Program) and from the Spanish Ministry of Economy and Competitivity (Juan de la Cierva Formación Program) to P. Arribas.

Mediterranean river ecosystems are subjected to intense human pressures and impacts that affect both their aquatic and riparian communities. However, given their stratified position in the river ecosystem and varying ecological requirements, aquatic and riparian communities can respond differently to such pressures. These biological responses could also vary depending on the nature of the disturbances, the spatial scale considered and the indicators used as response variable. Here, we aim to assess the influence of the main human pressures present in Mediterranean rivers (agricultural land use and hydromorphological alteration) on the biodiversity and ecological condition indicators of both riparian and aquatic communities at two spatial scales: reach and basin. For this purpose, a total of 56 sampling sites covering the study area (Segura basin, SE Spain) were surveyed. Water beetles and woody riparian vegetation richness were used respectively as biodiversity surrogates of aquatic and riparian communities, and the Iberian Biomonitoring Working Party (IBMWP) and Riparian Quality Index (RQI) were used to assess the ecological status of both communities. As expected, we found a general decrease in both richness and ecological condition when human pressures increased, regardless of the spatial scale considered. Nonetheless, agricultural land use was the main pressure explaining riparian richness and quality, whereas aquatic communities' responses were highly related to hydromorphological alteration. Contrary to expected, in general, variables at basin scale had a greater effect than those variables operating at local scale. In addition, ecological condition indices responded more clearly to human pressures than biodiversity surrogates. Therefore, land use and hydrological planning at basin scale are essential complements to conservation and restoration efforts, traditionally carried out at reach scale, in order to maintain stream ecosystem integrity and biodiversity. © 2014 Elsevier Ltd., D.B. and D.S-F. were supported by a predoctoral (FPU, AP2009-0432) and postdoctoral grant (Juan de la Cierva program, JCI-2011-10529) respectively, both from the Spanish Ministry of Economy and Competitiveness (MINECO) of Spain. We also want to thank to the Euromediterranean Institute of Water for the fieldwork funding received from the project ‘Hydrological classification of the rivers and streams in the Segura basin and associated macroinvertebrate communities’.

This paper provides the description of a new species of Aphelocheirus (Hemiptera: Heteroptera: Aphelocheiridae), Aphelocheirus pemae sp. nov. from Morocco. The species was found in two sites located in different basins (Sebou and Moulouya rivers) that are separated by approximately 400 km. Photographs of the dorsal habitus of the female and illustrations of the male genitalic structures are provided. A graphical key to species of the genus in Western Europe and the Maghreb is also included. The new species can be easily distinguished by the unique shape of the left and right parameres and absence of apical spines on the aedeagus.

Salinity tolerance has enabled the colonization of inland saline waters and promoted species diversification in some lineages of aquatic insects. However, the mechanisms behind this tolerance, particularly the role of cuticle hydrocarbons (CHCs), are not well-known. We characterized the CHC profile of eight species of two water beetle genera (Nebrioporus, Adephaga: Dytiscidae and Enochrus, Polyphaga: Hydrophilidae), which span the fresh-hypersaline gradient, to: i) determine the interspecific variation of CHC composition in relation to species' salinity tolerance; ii) explore plastic adjustments in CHC profiles in response to salinity changes at the intraspecific level in saline-tolerant species. CHC profiles were highly species-specific, more complex and diverse in composition, and characterized by longer-chain-length compounds in the species with higher salinity tolerance within each genus. Higher salinity tolerance in the Enochrus species was also associated with an increase in the relative abundance of branched alkanes, and with a lower proportion of n-alkanes and unsaturated compounds. These CHC characteristics are related with improved waterproofing capacity and suggest that reducing cuticle permeability was one of the key mechanisms to adapt to saline waters. Similar CHC composition patterns were found at the intraspecific level between populations from lower and higher salinity sites within saline-tolerant species of each genus. These saline species also displayed an extraordinary ability to adjust CHC profiles to changing salinity conditions in the laboratory in a relatively short time, which reflects great plasticity and a high potential to deal with daily and seasonal environmental fluctuations in the highly dynamic saline habitats.

Under global change, the ion concentration of aquatic ecosystems is changing worldwide. Many freshwater ecosystems are being salinized by anthropogenic salt inputs, whereas many naturally saline ones are being diluted by agricultural drainages. This occurs concomitantly with changes in other stressors, which can result in additive, antagonistic or synergistic effects on organisms. We reviewed experimental studies that manipulated salinity and other abiotic stressors, on inland and transitional aquatic habitats, to (i) synthesize their main effects on organisms’ performance, (ii) quantify the frequency of joint effect types across studies and (iii) determine the overall individual and joint effects and their variation among salinity–stressor pairs and organism groups using meta-analyses. Additive effects were slightly more frequent (54%) than non-additive ones (46%) across all the studies (n ¿ 105 responses). However, antagonistic effects were dominant for the stressor pair salinity and toxicants (44%, n ¿ 43), transitional habitats (48%, n ¿ 31) and vertebrates (71%, n ¿ 21). Meta-analyses showed detrimental additive joint effects of salinity and other stressors on organism performance and a greater individual impact of salinity than the other stressors. These results were consistent across stressor pairs and organism types. These findings suggest that strategies to mitigate multiple stressor impacts on aquatic ecosystems should prioritize restoring natural salinity concentrations. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.

Water salinity and ionic composition are among the main environmental variables that constrain the fundamental niches of aquatic species, and accordingly, physiological tolerance to these factors constitutes a crucial part of the evolution, ecology, and biogeography of these organisms. The present study experimentally estimated the fundamental saline and anionic niches of adults of two pairs of congeneric saline beetle species that differ in habitat preference (lotic and lentic) in order to test the habitat constraint hypothesis. Osmotic and anionic realised niches were also estimated based on the field occurrences of adult beetle species using Outlying Mean Index analysis and their relationship with experimental tolerances. In the laboratory, all of the studied species showed a threshold response to increased salinity, displaying high survival times when exposed to low and intermediate conductivity levels. These results suggest that these species are not strictly halophilic, but that they are able to regulate both hyperosmotically and hypoosmotically. Anionic water composition had a significant effect on salinity tolerance at conductivity levels near their upper tolerance limits, with decreased species survival at elevated sulphate concentrations. Species occupying lentic habitats demonstrated higher salinity tolerance than their lotic congeners in agreement with the habitat constraint hypothesis. As expected, realised salinity niches were narrower than fundamental niches and corresponded to conditions near the upper tolerance limits of the species. These species are uncommon on freshwater-low conductivity habitats despite the fact that these conditions might be physiologically suitable for the adult life stage. Other factors, such as biotic interactions, could prevent their establishment at low salinities. Differences in the realised anionic niches of congeneric species could be partially explained by the varying habitat availability in the study area. Combining the experimental estimation of fundamental niches with realised field data niche estimates is a powerful method for understanding the main factors constraining species' distribution at multiple scales, which is a key issue when predicting species' ability to cope with global change.

The establishment of protected areas is one of the main strategies to reduce losses of biodiversity. While a number of studies have evaluated the effectiveness of existing reserves in preserving representative samples of ecosystem and species diversity, there has been no systematic assessment of their effectiveness in terms of conserving evolutionary history. We used comprehensive phylogenies of four lineages of aquatic Coleoptera to investigate (i) the performance of National Parks (NPs) in representing the phylogenetic diversity (PD) of the Iberian Peninsula; (ii) the representation in NPs of the species with the highest conservation priority, as identified from a combination of their evolutionary distinctiveness and vulnerability; and (iii) whether species richness may be a good surrogate of PD when selecting new conservation areas. Our results show that Iberian NPs perform poorly in the preservation of freshwater PD. In most cases PD was not different from a random expectation, but when it did differ, PD in NPs was always lower than that obtained by a random selection of the same number of species. We also found that most of the highly evolutionarily distinct and vulnerable taxa were not covered by any NP. Finally, when additional conservation areas were selected maximizing the number of unrepresented species, the variation in PD could be very high, and as a consequence, depending on the group and the number of areas added, they could preserve much less evolutionary history than when they were specifically selected to maximize PD. © 2013 Elsevier Ltd., This research was supported by postdoctoral grants from the Spanish Ministry of Education and Fundación Séneca to PA and DSF respectively, a predoctoral grant from the Fundación Séneca to FP, project 023/2007 from the Spanish Ministry of Environment and projects CGL2007-61665 and CGL2010-15755.

Aim: We hypothesized that mechanisms underlying beta diversity in rivers would differ between gradients where (1) natural stressors result in progressive species turnover with high specificity and (2) anthropogenic stressors result in the loss of specialist taxa thus giving rise to nestedness. Location: Great Britain, the Iberian Peninsula and the Himalayan Mountains. Methods: We analysed five datasets describing benthic macroinvertebrates sampled along natural (elevation, salinity) and anthropogenic (acidity, metals, land use) stress gradients. Predictions were tested by fitting models relating species richness and beta-diversity components (total, turnover and nestedness dissimilarities) to putative stress intensity (i.e. the degree to which a particular environmental constraint filters species occurrence). Results: Stress intensity accounted for most of the variability in species richness (r2 = 0.64–0.93), which declined with increasing stress. Dissimilarity in community composition between locations increased with the difference in stress intensity for all datasets. For natural stressors, beta-diversity patterns mainly reflected species turnover, whilst for anthropogenic stressors beta diversity mainly reflected nesting of subsets of species as stress intensity increased. Main conclusions: Our results support the hypothesis that natural and anthropogenic stressors generate contrasting patterns in beta diversity that arise through different mechanisms.

As species' physiological breadth determines their potential to deal with environmental changes, and influences individuals' survival and the persistence of populations, information about lethal and sublethal responses could be fundamental for conservation purposes. 2. We used a standard experimental approach to explore mortality and behavioural avoidance responses (i.e. flight and emersion from the water) to a combination of acute heat and osmotic stress on six species of saline water beetles (belonging to Enochrus, Nebrioporus, and Ochthebius genera). 3. Heat stress affected survival and behavioural responses in all of the species, whereas osmotic stress and the interaction between both stressors only showed significant effects for the Ochthebius genus. Behavioural and survival patterns were highly interrelated across the stress gradients. The Enochrus and Nebrioporus studied species showed maximum avoidance activity at 35-40 ◦ C, and a short (< 30 min) exposure to 45 ◦ C was lethal. Ochthebius species were the most heat tolerant and displayed increasing behavioural responses with increasing temperature. In the Nebrioporus and Ochthebius genera, the species occupying lotic, more environmentally stable habitats, showed greater mortality, and avoidance responses were higher or initiated at lower stress thresholds than lentic species. In contrast, both Enochrus species displayed a similar mortality, and the lentic species E. bicolor emerged and flew more than the lotic E. falcarius, in concordance with its higher dispersal capacity. 4. Avoidance responses could provide interesting information about species' physiological amplitudes as a complement to lethal responses. The lotic species here studied showed narrower physiological amplitude (i.e. N. baeticus and O. glaber )o r lower dispersal ability (i.e. E. falcarius) than their lentic relatives; both traits could result in a higher vulnerability of lotic species to thermal habitat changes.

Arribas, P., Andujar, C., Sanchez-Fernandez, D., Abellan, P. & Millan, A. (2012). Integrative taxonomy and conservation of cryptic beetles in the Mediterranean region (Hydrophilidae). —Zoologica Scripta, 00, 000–000. Because biodiversity inventory forms the basis for the effective conservation of species and habitats, there is an imperative need to discover and describe new species. A significant part of presently unknown biodiversity is constituted by cryptic species complexes, where traditional taxonomy usually fails due to a lack of clear taxonomic characters in the external structures of specimens. Integrative taxonomy offers a powerful tool to shed light on this part of encrypted biodiversity, combining multiple operational criteria in an evolutionary context in order to delineate species boundaries. The present study used an integrative approach to explore the species boundaries in a water beetle complex (Enochrus falcarius species complex) inhabiting saline streams, a rare and threatened habitat across the Mediterranean region. First, hypotheses about the candidate species on the basis of phylogenetic analyses and biogeographical information were proposed. Second, lineage divergence was evaluated between candidate species using (i) molecular cluster delimitation, (ii) morphometry (both linear body morphometrics and pronotum outlines) and (iii) ecological niche similarity estimates. We found divergence between candidate species on the basis of molecular, biogeographical and niche information, and consequently, four species were delimited within the E. falcarius complex (i.e. Enochrus jesusarribasi sp. n., Enochrus blazquezae sp. n., Enochrus risii sp. n. and Enochrus falcarius), despite the fact that they showed high morphological similarity. Enochrus falcarius, as previously considered, had not been proposed to be of conservational concern, because until now, it had been regarded as a single broadly distributed species in the Mediterranean region. However, the four entities here delimited within this species complex displayed characteristics that categorised them as vulnerable taxa. Hence, these results show how applying integrative taxonomy approaches and rapid vulnerability assessments to lineages from threatened habitats with the potential to comprise cryptic diversity could become a fundamental tool for biodiversity conservation, driving the discovery of cryptic species and consequently the modification of previous, inadequately evaluated vulnerability categorisations.

Summary 1. We test the hypothesis that the physiological tolerance of corixids for saline conditions determines, at least partially, their occurrence along a salinity gradient that encompasses a variety of anionic compositions. 2. Three species of Sigara, S. nigrolineata (fresh waters), S. scripta (hyposaline waters) and S. selecta (mesosaline and hypersaline waters) were selected, and it was predicted that species occurring in the most saline waters would be ion regulation specialists that are more tolerant of higher salinity, while species living in fresh or hyposaline waters would be generalist regulators in relation to different anions, and therefore less tolerant of higher salinity. 3. Niche breadth was quantified using field data for both water conductivity and anionic composition (realised niche). In addition, physiological tolerance in relation to conductivity and anionic composition (fundamental niche) was estimated in laboratory tests using eggs, nymphs and adults of all species. 4. Sigara nigrolineata adults showed the most limited conductivity tolerance and were generalists in relation to different anionic water compositions. Sigara scripta demonstrated tolerance of hyposaline and mesosaline waters and higher survival rates in sulphated waters. Sigara selecta was the only species occupying hypersaline waters that showed a preference for anion chloride. 5. Sigara scripta was the only species coexisting with the other two species. This can be explained by the overlap found in conductivity and anionic composition niche dimensions at the lower (S. nigrolineata) and upper (S. selecta) tolerance limits. 6. Young life-stages of the species showed similar responses but less tolerance of higher salinity than adults; this was the case for eggs of S. nigrolineata and nymphs of S. scripta and S. selecta. 7. Physiological limitations were not found in relation to fresh and less saline waters in S. selecta, so other factors, probably involving biotic interactions, may play an important role in this species.

Summary 1. Coleoptera species show considerable diversity in life histories and ecological strategies, which makes possible their wide distribution in freshwater habitats, including highly stressed ones such as saline or temporary waterbodies. Explaining how particular combinations of traits allow species to occupy distinctive habitats is a central question in ecology. 2. A total of 212 sites, sampled over a wide range of inland aquatic habitats in the south-eastern Iberian Peninsula, yielded 272 species belonging to 68 genera and 11 families. The affinities of genera for 11 biological and 11 ecological traits, gathered from literature and the authors’ own expertise, were used to assess the degree of congruence between taxonomic, biological and ecological traits. 3. Taxonomic richness was significantly related to the number of both biological and ecological trait categories, with the richest families also showing the highest functional and ecological diversity. A fuzzy correspondence analysis performed on the abundance-weighed array of biological traits separated genera according to categories of diet, feeding habits, respiration, reproduction and locomotion. A similar analysis of ecological traits revealed that preferences related to longitudinal distribution (headwater to mouth), local habitat and current velocity best discriminated genera. At the family level, there was a distinctive functional grouping of genera based on biological traits. Only Elmidae showed noticeable homogeneity across genera for both biological and ecological traits. 4. Co-inertia analysis demonstrated a significant match between biological and ecological traits (Rv-correlation = 0.35, P

In Spain, national parks represent the mainstay of conservation polices and attempt to protect the most representative natural ecosystems. However, studies on the ecology and conservation of aquatic biodiversity within protected areas are still scarce. This study aimed at compiling an inventory of the macroinvertebrate families inhabiting the aquatic ecosystems of each mountainous Spanish national park (Sierra Nevada, Cabaneros, Ordesa, Picos de Europa, Aiguestortes and Monfrague). The results were used to answer two questions: (i) Which environmental variables are related to macroinvertebrate composition and richness in these protected ecosystems? (ii) Which taxon or group of taxa could act as biodiversity surrogates? Sampling was carried out in 81 aquatic ecosystems across the six national parks during the summers of 2008–2010. The national parks with the highest richness were Picos de Europa and Cabaneros. Overall, the six parks incorporated 66.2% of the taxa included in the Iberian checklist. Multivariate techniques showed that maximum altitude and the presence of lotic habitats were the most important variables related to different community compositions. The best richness model included the presence of a lotic habitat, together with the percentage of the catchment area with non-irrigated agriculture and siliceous geology. Selecting several diverse lotic and lentic water bodies at different altitudes provides the best way of representing Iberian macroinvertebrate diversity. Coleoptera family richness may be used as a macroinvertebrate biodiversity surrogate in Iberian mountainous protected areas because it displayed the highest correlation with the other taxonomic groups and remaining richness values. Such an indicator could be complemented with the use of Odonata family richness for standing waters. The adequacy of Coleopera and Odonata as biodiversity surrogates should be tested at a wider geographic scale, and other surrogacy concepts (e.g. community composition) considered for assessing the role of this network in the protection of rare and endemic species. Copyright © 2012 John Wiley & Sons, Ltd.

The investigation of flow-ecology relationships constitutes the basis for the development of environmental flow criteria. The need to understand hydrology-ecology linkages in natural systems has increased owing to the prospect of climate change and flow regime management, especially in water-scarce areas such as Mediterranean basins. Our research quantified the macroinvertebrate community response at family, genus and species level to natural flow regime dynamics in freshwater streams of a Mediterranean semiarid basin (Segura River, SE Spain) and identified the flow components that influence the composition and richness of biotic assemblages. Flow stability and minimum flows were the principal hydrological drivers of macroinvertebrate assemblages, whereas the magnitude of average and maximum flows had a limited effect. Perennial stable streams were characterized by flow sensitive lotic taxa (Ephemeroptera, Plecoptera and Trichoptera) and intermittent streams by predominately lentic taxa (Odonata, Coleoptera, Heteroptera and Diptera). Relatively minor biological changes were recorded for intermediate flow regime classes along a gradient of flow stability. Seasonal variation and minimum flows are key hydrological components that need to be considered for river management and environmental flows in the Segura River basin and other Mediterranean basins. The anthropogenic modification of these parameters, due to both human activities and climate change, would probably lead to significant changes in the structure and composition of communities in perennial stable streams. This would be characterized by a reduction of flow sensitive Ephemeroptera, Plecoptera and Trichoptera taxa and an increase in more resilient Odonata, Coleoptera, Heteroptera and Diptera taxa. © 2012 John Wiley & Sons, Ltd.

Extensive biological databases are valuables ecological research tools that form the basis of biodiversity studies. However, it is essential to perform an assessment of the inventories’ completeness for their use in ecological and conservational research, and this is especially true for non-emblematic groups. Using four exhaustive databases compiled for four taxonomic groups (aquatic beetles, aquatic bugs, bryophytes and orchids), in a semiarid Mediterranean region, the aim of this study was to estimate the degree of completeness for the inventory of each taxa and to identify those spatial units that could be considered to be sufficiently-surveyed (UTM 10 × 10 km squares). Then, the degree of environmental representativeness of the databases was assessed, as well as those factors that could have caused biased sampling efforts. Lastly, the usefulness of each database for conservational purposes was discussed. The results of the present study highlighted the lack of complete and extensive inventory data; as the best sampled group did not even reach 25% of sufficiently-surveyed squares in the territory (in the case of aquatic bugs) and none of the squares presented reliable inventories in the case of bryophytes. Although these results suggested that recording was skewed by relatively simple climatic variables, the sufficiently-surveyed squares were evenly distributed across physioclimatic subregions, what enables their use in further ecological studies. The authors would like to emphasise the potential of these procedures to locate areas in need of further sampling as well as to aid in the design of more effective regional conservation schemes.

Aim The contrasting habitat permanence over geological time-scales of lotic and lentic habitats may impose different constraints on the dispersal ability of their macroinvertebrate populations, and ultimately on the degree of equilibrium with current climate. We aim to test for differences between species typical of either habitat type in their potential versus realized distributions as a surrogate measure of degree of climate equilibrium, both in refuges and more recently deglaciated areas. Location Western Europe. Methods We focus on 99 Iberian diving beetles (family Dytiscidae). A multidimensional envelope procedure was used to estimate their potential distributions, which were projected for different spatial scales. At the continental scale we calculated the percentage of countries with climatically suitable conditions for each species over those actually occupied (range filling). At the regional scale, we estimated realized distributions using: (1) convex hull polygons for Sweden and the Iberian Peninsula; and (2) generalized linear models for the Iberian Peninsula. Results In the Iberian Peninsula, differences in the degree of equilibrium with climatic conditions between lotic and lentic species were few, if any. However, at the continental scale we found significant differences, with lentic species closer to equilibrium than lotic species. In the recently deglaciated area (Sweden) the subset of species with ranges wide enough to encompass Iberia and Scandinavia were mostly lentic, and all were closer to climatic equilibrium without significant differences between habitat types. Main conclusions Our results show that, at continental scales, climate equilibrium is not concordant between the habitat types across western Europe. We hypothesize that: (1) the differences between refuge areas in dispersal ability are erased probably due to long-term climatic stability, allowing enough time to reach equilibrium, and (2) the species with wide geographical ranges able to recolonize recently deglaciated areas should have the highest dispersal abilities, and are closer to climatic equilibrium.

Este documento presenta un análisis de los entrecruces que se usan en la configuración de los nueve estilos tejidos en sombreros de paja, producidos por la comunidad de Colón, Génova, Nariño, Colombia. Estos sombreros, se conocen bajo los nombres de Común, Pintao, Gallineto-Granizo, Fino, Cuadros, Calado o Huecos, Costeño o Vueltiao, Bandera y Ojo de Perdiz. La interpretación del pensamiento geométrico que se emplea para su diseño tuvo como referencia, entre otros autores, metodologías propuestas por Gerdes (1999) y Aroca (2009), que han sido aplicadas en el continente Africano y en Suramérica. Además, se estableció la existencia de una lógica de construcción, basada en estrategias de conteo y de organización que se evidencian en el entrecruce de las iracas o chullas. Se evidenció una evolución por medio de la aparición de nuevas técnicas, que implican modificaciones en el tejido básico conllevando a cambios en la lógica de construcción y como consecuencia, se generan nuevos diseños, que buscan responder a las necesidades de la sociedad actual. Los artesanos abordan la simetría en sus diseños, aplicando complejos procesos de estimación y de conteo, que se tratarán de mostrar. Las figuras simétricas corresponden a triángulos, cuadriláteros y hexágonos, que se organizan en franjas, que cumplen con propiedades de congruencia, de semejanza y de paralelismo, siendo éste un lenguaje de interpretación de los investigadores, que se valida en el momento de mostrar los resultados a comunidades académicas.This document presents an analysis of the interlaces used in the configuration of nine straw hat styles produced by the Colón - Génova community, Nariño, Colombia. These hats are known under the names of Común, Pintao, Gallineto- Granizo, Fino, Cuadros, Calado or Huecos, Costeño or Vueltiao, Bandera and Bird's-Eye. The interpretation of the geometric thought employed in the design of these hats had like reference, between other authors, the methodologies proposed by Gerdes (1999) and Aroca (2009), that have been applied in the African continent and in South America. Besides, the existence of a logic of the construction became established, based in count strategies and organization that become evident in the crossed of the iracas or chullas. The evolution techniques were evidenced, which imply modifications in the basic fabric bearing to changes in the logic of the construction, resulting in the generation of new designs that search to fulfill to the needs of the present-day society. Craftsmen discuss the symmetry in their designs applying complex processes of estimate and count, which are tried to show. The symmetric figures correspond to triangles, quadrilateral and hexagons organized in stripes that fulfill properties of congruence, similarity and parallelism, being this a language of the researchers interpretation validated upon showing the results to academic communities.

Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur.

Aim In aquatic ecosystems, standing (lentic) and running (lotic) waters differ fundamentally in their stability and persistence, shaping the comparative population genetic structure, geographical range size and speciation rates of lentic versus lotic lineages. While the drivers of this pattern remain incompletely understood, the suite of traits making up the ability of a species to establish new populations is instrumental in determining such differences. Here we explore the degree to which the association between habitat type and geographical range size results from differences in dispersal ability or fundamental niche breadth in the members of the Enochrus bicolor complex, an aquatic beetle clade with species across the lentic–lotic divide. Location Western Mediterranean, with a special focus on North Africa, the Iberian Peninsula and Sicily. Methods DNA sequences for four loci were obtained from species of the E. bicolor complex and analysed using phylogenetic inference. Dispersal and establishment abilities were assessed in lentic–lotic species pairs of the complex, using flight wing morphometrics and thermal tolerance ranges as surrogates, respectively. Results There were clear differences in range size between the lotic and lentic taxa of the complex, which appears to have had a lotic origin with two transitions to standing waters. Only small differences were observed in temperature tolerance and acclimation ability between the two lotic–lentic sister species studied. By contrast, wing morphometrics revealed clear, consistent differences between lotic and lentic Enochrus species pairs, the latter having a higher dispersal capacity. Main conclusions We hypothesize that there have been two habitat shifts from lotic to lentic waters, which have allowed marked expansions in geographical range size in western Mediterranean species of the E. bicolor complex. Differences in dispersal rather than in establishment ability appear to underlie differences in geographical range extent, as transitions to lentic waters were associated with changes in wing morphology, but not in thermal tolerance range. In this lineage of water beetles, selection for dispersal in geologically short-lived lentic systems has driven the evolution of larger range sizes in lentic taxa compared with those of their lotic relatives.

1. Nowadays, it is widely accepted that increasing human activity is highly related to the current biodiversity loss, this fact being especially worrying in aquatic ecosystems, mainly in semi-arid areas. To date, studies on the biodiversity of small standing waters are focused on Central and Northern Europe, Mediterranean regions being poorly documented. 2. Here, data for aquatic Coleoptera in SE Iberia have been used to: (i) explore the relative contribution of standing waters to regional aquatic biodiversity, (ii) identify the environmental drivers structuring beetle assemblages, (iii) determine the degree to which standing water assemblages are nested subsets, and (iv) make recommendations for the conservation and management of the habitats studied. 3. Water beetles are a hyperdiverse group of aquatic insects which represent good surrogates of aquatic biodiversity. A total of 95 sites across eight habitat types were sampled, 174 species being recorded (11% were Iberian endemics). 4. Habitat types generally had distinct aquatic beetle faunas; a combination of conductivity, anthropogenic impact and altitude best explaining differences in assemblages across sites. Beetle faunas were significantly nested, this being the case across all sites, and for both fresh and saline systems independently. Disturbance was identified as a key driver of nestedness across sites overall, and particularly in freshwaters, whereas conductivity was more important in saline waters. 5. Our study identifies the biodiversity importance of lentic inland waters in the Iberian southeast, and points to the influence that human activities already exert on the invertebrate faunas of western Mediterranean wetlands.

Good distribution maps based on adequate sampling of a number of taxonomic groups are required to provide reliable conservation strategies. Nevertheless, it is common that inventories of many animal groups, particularly insects, are incomplete or nonexistent, with large gaps appearing once all available information of insects is mapped, especially when wide spatial scales are considered. Due to the lack of resources and manpower, the accomplishment of future field campaigns in these generally poorly surveyed areas should be directed so as to maximise the information obtained with the minimum survey effort. Using an exhaustive database of Iberian water beetles (which was relatively scarce and biased), we aim to prioritise areas to propose a planned survey design able to generate more accurate geographical representations of species distributions. For this, a prediction on the geographic distribution of the species richness of this group in the Iberian Peninsula was first obtained using the information coming from seven sets of well-surveyed grid cells determined by using progressively more exigent completeness values. Both observed and estimated by accumulation curves, species richness values of these different cell groups were subsequently used as the dependent variable in the modelling procedure. We used generalised linear models and 18 environmental variables as predictors. In this manner, 14 species richness predictions were obtained whose predictive power was assessed by a Jackknife procedure. The best model explained 57.5% of total deviance with a high mean Jackknife predictive error (29.9%). The overlay of these predictions with the survey effort map allows us to locate those areas where more sampling effort is necessary (areas of high predicted species richness that are not well inventoried).

Inland saline waters are globally threatened habitats that harbour unique assemblages of specialist invertebrates. In many Mediterranean regions, irrigation associated with intensive agriculture is lowering the salinity of these habitats, resulting in the loss of their specialist biota, although the mechanisms by which reductions in salinity lead to species loss are poorly understood. In the present study, the effects of reduced salinity on the temperature tolerance and thermal acclimatory abilities of two related species of hypersaline water beetles, Nebrioporus baeticus (Schaum) and Nebrioporus ceresyi (Aub´ e), are explored. Both upper (UTL) and lower thermal limits (LTL) are assessed, and both salinity and temperature are found to influence the thermal biology of Nebrioporus. Mean UTLs are greater in individuals of both species acclimated at high salinities, with salinity appearing to be more important than acclimation temperature in determining UTL. In both taxa, the lowest mean LTLs are recorded in individuals acclimated at the highest salinities and lowest temperatures; temperature-dependent acclimation is only reported after exposure to relatively high salinities. The data show that salinity influences the thermal tolerance and acclimatory ability of these hypersaline beetles, and that lowered salinity compromises the ability of adult Nebrioporus to cope with both heat and cold. Such an effect may partly explain why specialist species are lost from hypersaline habitats subject to salinity reductions, and suggests that ongoing reduction in salinity may compromise the ability of such specialist taxa to cope with rapid climate change.

The southeast of the Iberian Peninsula is a recognized area of high aquatic biodiversity, water beetles being one of the most well-known groups contributing to such biodiversity. The standing waters of this area show a high habitat diversity, occurring fresh, saline, temporary, permanent, karstic, endorheic, and artificial small water bodies. Despite this, there has been no attempt to analyze their contribution to local biodiversity. In this work, we identify the species inhabiting standing waters, analyze their contribution to the checklist from the study area, and recognize the species exclusive to this kind of habitat. We also highlight the most threatened species, identify the habitats which constitute biodiversity hotspots for this group, explore patterns of water beetle assemblage composition, and identify indicator species associated with each habitat type. We collected 125 species, 55 of them being typical to lentic habitats, in the set of 26 sampled standing water bodies, which means the 57% of the 218 species recorded in the most recent checklist for the study area. A total of 10 species are Iberian endemics and four can be considered threatened, Ochthebius irenae falling in both categories. Natural ponds showed the highest species richness (91 species), while saline water bodies (endorheic lagoons and continental salt-pans) contributed the most threatened species: Nebrioporus baeticus, Ochthebius delgadoi, Ochthebius tudmirensis and Ochthebius irenae. The most representative species for continental salt-pans was Ochthebius notabilis, for endorheic lagoons Ochthebius marinus and Hygrotus pallidulus, while Hydroglyphus geminus played this part in rice fields. Our results suggest that rice fields, endorheic lagoons, and continental salt-pans have specific water beetles assemblages, which could be used in bioassessment and conservation studies. In general, standing waters are seriously threatened in this area, particularly as a result of intensive agricultural activities. Thus, taking into account these ecosystems hold a high number of species, their continued degradation is likely to result in a significant loss of biodiversity, including key populations of a number of threatened and endemic species.

Analysis of the vulnerability of the aquatic beetles in the South Mediterranean side: the case of the Rif region (Morocco). There is a widespread agreement that rates of biodiversity loss are greater in freshwater systems than in other ecosystems. To be able to protect adequately the freshwater biodiversity, it is crucial to know what species and habitats require greater conservation effort. In this study, we identify the most threatened species of water beetles from the Rif (North of Morocco) using a categorization system to rank species according to their conservation priority or vulnerability. Haliplus andalusicus, Metaporus meridionalis, Hydrochus obtusicollis, Hydrochus tariqi, Limnebius mesatlanticus, Ochthebius atriceps, O. extraneus, and O. lanarotis were the most threatened species, for which reason they should be proposed to be included in a future Rif red list. Furthermore, Hydrochus obtusicollis and Ochthebius lanarotis are proposed for inclusion in the IUCN red list as "En danger". Both species are Moroccan endemic, with geographic ranges restricted to the Rif in the case of the fi rst species, and threatened by habitat loss. Effective protection of these species requires measures directed at the conservation of their habitats. Crucial target habitats for protection in the Rif include springs, headwater streams, middle reach stream, saline streams, marshlands and peat bogs. Resume. La perte de la biodiversite est plus accentuee dans les ecosystemes aquatiques continentaux que dans les autres types d'ecosystemes. L'elaboration d'une strategie de conservation adequate de la biodiversite aquatique s'avere donc cruciale. Elle doit cependant etre basee sur l'identifi cation des especes et des habitats necessitant un plus grand effort de conservation. Dans ce travail, les especes les plus menacees des coleopteres aquatiques du Rif (Nord du Maroc) sont identifi ees en utilisant un systeme de categorisation pour classer les especes selon leur priorite de conservation ou leur degre de vulnerabilite. Haliplus andalusicus, Metaporus meridionalis, Hydrochus obtusicollis, Hydrochus tariqi, Limnebius mesatlanticus, Ochthebius atriceps, Ochthebius extraneus et Ochthebius lanarotis presentent une haute vulnerabilite a une echelle regionale et meritent d'etre inscrites sur la future liste rouge des especes menacees du Rif. Parmi ces especes Hydrochus obtusicollis et Ochthebius lanarotis sont proposees pour qu'elles soient inscrites, sur la liste rouge IUCN dans la categorie "Endangered". Il s'agit de deux especes endemiques du Maroc, de distribution tres restreinte, la premiere exclusive du Rif, et leurs habitats souffrent de plusieurs impacts. L'etat de conservation de ces especes necessite que des mesures urgentes soient prises, pour la protection de leurs habitats. Les actions de preservation doivent inclure les habitats aquatiques du Rif comme les sources, les cours superieurs et moyens des oueds, les cours d'eau sales, les marais et les tourbieres.

The effects of seasonality and dilution stress on the functioning of Rambla Salada, a hypersaline Mediterranean stream in SE Spain, were evaluated. The stream is subject to diffuse freshwater inputs from the drainage of intensively irrigated agriculture in the catchment and periodic losses of water through an irrigation channel. Metabolic rates and the biomass of primary producers and consumers were estimated over a 2-year period. During the first year several dilution events occurred, while during the second year the salinity recovery reached predisturbance levels. Functional indicators were compared in the disturbance and recovery salinity periods. Primary production and respiration rates in the Rambla Salada ranged between 0.07–21.05 and 0.19–17.39 g O2 m−2 day−1, respectively. The mean values for these variables were 7.35 and 5.48 g O2 m−2 day−1, respectively. Mean net daily metabolism rate was 1.87 ± 0.52 g O2 m−2 day−1 and mean production/respiration ratio was 2.48 ± 1.1, reflecting autotrophic metabolism. The metabolic rates showed the typical seasonal pattern of Mediterranean open canopy streams. Therefore, gross primary production (GPP) and ecosystem respiration (ER) registered maximum values in summer, intermediate values in spring and autumn and minimum values in winter. The metabolic rates and biomass of consumers were greater in the disturbance period than in the recovery period. However, they did not show significant differences between periods due to their important dependence on seasonal cycle. Seasonality accounted for much of the temporal variability in GPP and ER (76% and 83% in the multiregression models, respectively). Light availability seems to be the most important factor for GPP and ER in the Rambla Salada. Autotrophic biomass responded more to variations in discharge and conductivity than to seasonal variations. In fact, it was severely affected by freshwater inputs after which the epipelic biomass decreased significantly and Cladophora glomerata proliferated rapidly. Epipelic algal biomass was the most sensitive parameter to dilution disturbance.

Extensive distributional data bases are key tools in ecological research, and good-quality data are required to provide reliable conservation strategies and an understanding of biodiversity patterns and processes. Although the evaluation of data bases requires the incorporation of estimates of sampling effort and bias, no studies have focused on these aspects for freshwater biodiversity data. We used here a comprehensive data base of water beetles from the Iberian Peninsula and the Balearic Islands, and examine whether these data provide an unbiased, reliable picture of their diversity and distribution in the study area. Based on theoretical estimates using the Clench function on the accumulated number of records as a surrogate of sampling effort, about a quarter of the Iberian and Balearic 50 × 50 km Universal Transverse Mercator grid cells can be considered well prospected, with more than 70% of the theoretical species richness actually recorded. These well-surveyed cells are not evenly distributed across biogeographical and physicoclimatic subregions, reflecting some geographical bias in the distribution of sampling effort. Our results suggest that recording was skewed by relatively simple variables affecting collector activity, such as the perceived ‘attractiveness’ of mountainous landscapes and protected areas with recently described species, and accessibility of sampling sites (distance from main research centres). We emphasize the importance of these evaluation exercises, which are useful to locate areas needed of further sampling as well as to identify potential biases in the distribution of current biodiversity patterns.

One of the most serious environmental problems is the current acceleration in the rate of species extinction associated with human activities, which is occurring particularly rapidly in freshwaters. Here we examine whether endemic water beetles are effectively protected by existing conservation measures in the Iberian Peninsula and the Balearic Islands, a region of high diversity and intense human pressure. We used an exhaustive database for aquatic beetles in the region to address such issues. Firstly, we identify the most threatened endemic taxa using a categorization system to rank species according to their conservation priority or vulnerability. Of the 120 endemic species of water beetles used in the analysis, only two (Ochthebius ferroi and Ochthebius javieri) were identified as being extremely vulnerable, 71 were highly vulnerable and 46 moderately vulnerable, with only a single species identified as having low vulnerability status. Since no Iberian species of aquatic Coleoptera has legal protection, the only conservation measure available for these species is the extent to which they occur in protected areas. Here we identify distributional hotspots for threatened endemic species, and evaluate the extent to which these are already included in the Natura 2000 network in Spain and Portugal. Despite a high degree of concordance between hotspots and Natura 2000 sites, the distribution of four species falls completely outside the network. The analysis also reveals that Natura 2000 fails to protect saline water bodies, despite their high conservation interest and narrow global distribution. The picture revealed here with water beetles is likely to be similar for others groups of freshwater macroinvertebrates, since Coleoptera are known to be good surrogates of aquatic biodiversity in the region. Finally, the degree of protection provided via Natura 2000, and the utility of red lists are discussed.

1. Biodiversity is probably at greater risk in freshwater systems than in other ecosystems. Although protected areas (PAs) play a vital role in the protection of biodiversity and are the mainstay of most conservation polices, the coverage of biodiversity by existing PA networks is often inadequate and few reserves are created that take into consideration freshwater biota. 2. In this paper an attempt is made to address the performance of protected areas in the context of freshwater biodiversity conservation using data records for water beetles in a Mediterranean river basin. 3. Although the present PAs in the study area cover a relatively high number of water beetle species, the distribution and extent of reserves is still inadequate or insufficient to protect freshwater biodiversity, especially species of conservation concern. 4. Alternative area-selection methods (hotspots and complementary) were more efficient than PAs for representing water beetles. Within these, complementarity was the most efficient approach, and was able to represent all species in a significantly lower area than the current PA network. On the other hand, the future Natura 2000 Network will result in a great increase in the total area of protected land as well as in the biodiversity represented. 5. Unfortunately, the occurrence of a species within a protected area is not a guarantee of long-term survival because the extent of PAs is often insufficient and disturbances occur outside park boundaries. Thus, whole-catchment management and natural-flow maintenance are indispensable strategies for freshwater biodiversity conservation. Copyright © 2006 John Wiley & Sons, Ltd.

The effect of stressors on biodiversity can vary in relation to the degree to which biological communities have adapted over evolutionary time. We compared the responses of functional features of stream insect communities along chronic stress gradients with contrasting time persistence. Water salinity and land use intensification were used as examples of natural (long-term persistent) and anthropogenic (short-term persistent) stressors, respectively. A new trait-based approach was applied to quantify functional diversity components and functional redundancy within the same multidimensional space, using metrics at the taxon and community levels. We found similar functional responses along natural and anthropogenic stress gradients. In both cases, the mean taxon functional richness and functional similarity between taxa increased with stress, whereas community functional richness and functional redundancy decreased. Despite the differences in evolutionary persistence, both chronic stressors act as strong nonrandom environmental filters, producing convergent functional responses. These results can improve our ability to predict functional effects of novel stressors at ecological and evolutionary scales., C. Gutiérrez-Cánovas was partially supported by a pre-doctoral grant from the Fundación Séneca (Agencia Regional de Ciencia y Tecnología, Región de Murcia). D. Sánchez-Fernández was supported by the “Juan de la Cierva” program of the Spanish Ministry of Economy and Competitiveness. The salinity surveys were financed by the Ministerio de Ciencia e Innovación (Spain) through I+D+i project no. CGL2006-04159/BOS (A. Millán). N. Bonada acknowledges the BioFresh EU-funded project–Biodiversity of Freshwater Ecosystems: Status, Trends, Pressures, and Conservation Priorities (7th FWP contract No 226874).

© 2014 Elsevier Ltd. All rights reserved. Wetlands are among the most threatened habitats and the species they support among the most endangered taxa. Measuring and monitoring wetland biodiversity is vital for conservation, restoration and management, and often relies on the use of surrogate taxa. Waterbirds are commonly used as flagships of biodiversity and are the subject of major conservation initiatives. Therefore, it is important to assess the extent to which waterbirds indicate the general biodiversity of wetlands and serve as surrogates. We explore the relationships between community composition and species richness of waterbirds and aquatic macroinvertebrates in 36 Ramsar wetlands in southern Spain to assess if waterbirds are good surrogates for other taxonomic groups. Specifically, we aimed to (i) test the congruence of patterns of species composition and richness among waterbirds and aquatic macroinvertebrates; and (ii) investigate which environmental variables are associated with the biodiversity patterns of waterbirds and macroinvertebrates, with the purpose of identifying key factors explaining potential discordance in these patterns. We found a limited concordance between assemblage patterns of both taxonomic groups that may be related to their contrasting responses to environmental gradients. Assemblages of waterbirds appear to be more affected by climate variables and water surface area, whereas conductivity was the most important factor influencing macroinvertebrate communities. Furthermore, we found a negligible or inverse relationship in their patterns of richness, with wetlands with higher waterbird species richness showing significantly lower richness of Hemiptera and macroinvertebrate families, and no significant relationship with Coleoptera. In addition, GLM models showed that, in general, different environmental variables are related with the richness patterns of the different taxonomic groups. Given the importance of the Ramsar convention for the conservation of an international network of wetlands, our findings underline the limited potential of waterbirds as aquatic biodiversity indicators in Mediterranean wetlands, and the need for caution when using waterbirds as flagships. An integrative analysis of different biological communities, using datasets from different taxonomic groups, is a necessary precursor for successful conservation policies and monitoring. Our results illustrate the need to create a diversified and complete network of protected sites able to conserve multiple components of wetland biodiversity.

The ESACIB (‘EScarabajos ACuáticos IBéricos’) database is provided, including all available distributional data of Iberian and Balearic water beetles from the literature up to 2013, as well as from museum and private collections, PhD theses, and other unpublished sources. The database contains 62,015 records with associated geographic data (10×10 km UTM squares) for 488 species and subspecies of water beetles, 120 of them endemic to the Iberian Peninsula and eight to the Balearic Islands. This database was used for the elaboration of the “Atlas de los Coleópteros Acuáticos de España Peninsular”. In this dataset data of 15 additional species has been added: 11 that occur in the Balearic Islands or mainland Portugal but not in peninsular Spain and an other four with mainly terrestrial habits within the genus Helophorus (for taxonomic coherence). The complete dataset is provided in Darwin Core Archive format., Some data sets have been obtained with the support of additional projects from the Spanish Government, especially 023/2007, CGL2007-61665 and CGL2013-48950. DS-F has a “Juan de la Cierva” contract from the Spanish Ministry of Economy and Competitiveness.

The intensification of agriculture has resulted in the loss of many aquatic ecosystems in southern Europe. Despite this, the construction of irrigation pools and reservoirs to retain the water necessary for intensive cultivation may also provide new habitats for macroinvertebrates. The biotic and abiotic attributes of 40 such reservoirs in south-eastern Spain were studied to determine the presence of macroinvertebrates, and to discover if there is such a thing as an optimal design of an artificial pond for maximizing macroinvertebrate richness. A total of 72 macroinvertebrate taxa belonging to 38 families were recorded from the pools examined. Pools constructed with low-density polyethylene covered with sand and stones contained a significantly greater species richness, abundance and diversity of macroinvertebrates than those constructed with high-density plastic materials. The treatment with algicide, and the presence of emergent and submerged vegetation, accounted for most of the deviance when modelling species richness by means of logistic regression.

Summary 1. It is increasingly recognised that adequate measures of biodiversity should include information on the ‘relatedness’ of species within ecological assemblages, or the phylogenetic levels at which diversity is expressed. Taxonomic distinctness measures provide a series of indices to achieve this, which are independent of sample size. Taxonomic distinctness has been employed widely in marine systems, where it has been suggested that this index can provide a reliable measure of anthropogenic impact. 2. We tested the behaviour of three related taxonomic distinctiveness indices (Average Taxonomic Distinctness, Δ+; Variation in Taxonomic Distinctness, Λ+; and Total Taxonomic Distinctness, sΔ+) in relation to putative levels of anthropogenic impact in inland waters and their potential utility in environmental monitoring, using an extensive data set for aquatic beetles from the south-east of the Iberian Peninsula. 3. Taxonomic distinctness measures were not able to identify human disturbance effects and there were no clear relationships between these new biodiversity measures and the disturbance level recorded at individual localities. Furthermore, the taxonomic distinctness measures used were apparently less sensitive to the effects of anthropogenic impact than other diversity metrics, such as species richness and rarity. 4. We conclude that taxonomic distinctness indices may not always perform as well as other metrics in the assessment of environmental quality. In addition, taxonomic distinctness measure should be interpreted with caution, as their performance and ability to detect anthropogenic disturbance may depend on the phylogenetic structure of sampled taxa within a region, and their evolutionary and ecological history.

Water beetles were examined for use as potential biodiversity indicators in continental aquatic ecosystems in a semiarid Mediterranean region, the Segura river basin (SE Spain). The indicator value of water beetles was investigated by examining the degree to which their species richness patterns was correlated with other groups (Plecoptera, Trichoptera, Mollusca, Heteroptera and Ephemeroptera), and the efficiency of water beetle area networks (selected by complementarity) in conserving overall groups richness. The species richness patterns of Coleoptera, Ephemeroptera, Plecoptera and Trichoptera were significantly correlated with the Remaining Richness value (RR), defined as the total number of species found at a site (of all six groups examined) minus the number of species belonging to the considered indicator group. Area networks for Coleoptera selected by complementarity represented the highest RR percentage (84.46%) and contained more than 78% species of each group. Furthermore, water beetles meet most of the criteria proposed in the literature for choosing biodiversity indicator taxa. In our study, the correlation values and the percentage of species represented by family, genus and species complementary networks were similar and we suggest that the higher taxa of water beetles (genera or families) can be used as biodiversity surrogates for cost-effective practical surveys.

Saline inland waters are globally threatened habitats harbouring many specialised endemic species, which often have restricted geographic ranges, and occur as highly isolated populations. We studied the genetic variation and phylogeography of Ochthebius glaber Montes and Soler, a rare and endangered water beetle endemic to hypersaline streams in the South and Southeast of the Iberian Peninsula. We used a 633 bp fragment of cytochrome oxidase subunit 1 gene to determine the genetic diversity and phylogeographic structure within this species, and interpret this in the light of the speciesȁ9 conservation requirements. Thirteen populations were sampled across the speciesȁ9 geographic range, and genetic diversity found to be very high, with 37 haplotypes across the 71 specimens examined (p-distance 0.2–7.3%, average 3.1±0.4). Phylogeographic analyses revealed a surprisingly high degree of geographical structure, detectable among populations separated by relatively short geographical distances, with three main groups of haplotypes which have apparently been isolated for significant periods of time. Past fragmentation and contiguous range expansion events were inferred as the main causes of the detected geographical associations of haplotypes. The establishment of independent evolutionary lineages as conservation units is particularly important for species inhabiting saline habitats such as O. glaber, which is endangered by habitat loss across most of its distribution. However, given the natural instability of hypersaline environments, the conservation of a network of populations and potential habitats would be necessary to enable the preservation of the process generating and maintaining the diversity of the species.

The Mar Menor is a Mediterranean coastal lagoon of high conservation interest, but highly threatened by non-point pollution derived from agricultural lands. This is the first comprehensive study that evaluates the inputs into the Mar Menor from a drainage channel and the Albujon wadi, the main watercourse, and their influence on the trophic state of the lagoon. Discharge variation during the study period was closely related to the precipitation pattern. Suspended sediments and particulate organic matter loads greatly increased with flash floods. Nitrate concentrations, too, increased after heavy autumn rains through washing of the nitrates accumulated in soils, although no significant correlations were found between nitrate concentrations and precipitation or discharge. The nitrate load depended on several factors including the intensity and frequency of precipitation, and the nitrates accumulated in soils as a result of fertilisation. Phosphate concentrations decreased with higher flows. The total input into the lagoon from the two discharges estimated for the period September 2002–October 2003 were 10,142 t.yr−1of suspended sediments, 389 t.yr−1 of particulate organic matter, 2,010 t.yr−1 of dissolved inorganic nitrogen (93 % as NO−3) and 178 t.yr−1 of soluble reactive phosphorus. The Albujon wadi exported about 80% of the N load and 70% of the P load. Higher flows contributed approximately 80% of the total discharge and nutrient loads, 99% of suspended sediment and 88% of the particulate organic matter. Mean suspended solids and nutrient concentrations in the lagoon followed a spatial pattern, decreasing with distance from the mouth of the Albujon wadi. Water nitrate and phosphate concentrations in the Mar Menor lagoon were lower than reference limits for eutrophic conditions, except after heavy rains. Nutrient concentrations were positively correlated with precipitation variables and particulate and nutrient inputs. Phosphorus was the most limiting nutrient in the Mar Menor, the DIN:SRP ratios found being higher than the Redfield ratio on all sampling dates. Phytoplankton bloom in the lagoon was only found next to the Albujon mouth during late summer and extending 5000 m into the lagoon in autumn as a consequence of large freshwater discharge caused by flash floods. Around 53.6% of the variation in chlorophyll a in the lagoon was explained by the NH4 and NO3 inputs and distance from the Albujon mouth. A good deal of P input into the lagoon is retained in the sediments, supporting a high biomass of the benthic macroalga Caulerpa prolifera in spring and summer.

SUMMARY 1. This is the first study on the life cycle, growth and production of Sigara selecta ,a Palearctic corixid species typical of brackish and saline waters, at the warmest limit of its European distributional range. The study combines field and laboratory approaches. 2. The S. selecta population studied was multivoltine, producing four asynchronous cohorts from early spring to December and overwintering in the adult state. Development time from egg to first adult ranged from 2 to 3 months. A minimum temperature threshold of 10 � C and diel amplitude of ‡10 � C were observed for reproduction and oviposition. 3. Maximum density and biomass were reached in mid spring and early autumn. The sex ratio was unbalanced, females dominating during most of the year, except in spring, when the sex ratio was balanced or dominated by males during the first adult emergence. 4. Laboratory rearing experiments at constant temperatures (18, 22 and 26 � C) pointed to a significant effect of temperature on egg development and nymphal growth. In the range of temperatures tested, both egg and nymphal instar duration decreased with increasing temperature. Mean nymphal development time varied from 43 days at 26 � C to 71 days at 18 � C, with a mean of 57 days. Survivorship was independent of temperature. 5. A reduction in nymphal and adult length was observed with increasing temperature. 6. Growth rates decreased with increasing body mass and increased as temperature increased. The first nymphal instar had the highest length increments and growth rates in all temperature treatments. 7. Satisfactory agreement was found between the field and laboratory degree-days required for complete development from egg to first adult. At constant and variable thermal regimes, degree-days decreased with increasing temperature. 8. Rate of growth in the field could be predicted with reasonable accuracy from a simple model obtained as a function of body mass. The model explained 67% of the variability in growth rates. 9. Annual production and production/biomass ratio (P/B) of S. selecta estimated by the Instantaneous Growth method were 1.28 g m )2 year )1 and 13.71, respectively. Spring and autumn cohorts contributed 32% and 54%, respectively, of total annual production. Maximum production corresponded to intermediate temperature periods, although summer production may have been underestimated because of the longer sampling interval relative to cohort interval production. The Size Frequency method underestimated production by at least 18% with respect to the Instantaneous Growth method.

The biodiversity of freshwater systems is endangered, especially in Mediterranean semiarid areas such as the south east of the Iberian Peninsula, whose rich and endemic biota is threatened by the development of surrounding land-crop irrigation. For this reason, the prioritization of areas for biodiversity conservation is an urgent target. In this study we used data records of water beetles from a province of the southeast of Spain for assessing priority areas for freshwater biodiversity conservation. We compare the performance of various area-selection methods, ranging from scoring procedures to complementarity-based algorithms, which are based on different criteria such as richness, rarity and vulnerability. The complementarity approaches were more efficient than methods using scoring or richness and rarity hotspots for representing conservation targets in a given number of areas and for identifying the minimum set of areas containing all species at least once. Within these, the richness-based algorithm was more efficient than rarity-based algorithm. Crucial target habitats for aquatic biodiversity conservation in the area studied are streams at medium altitude, hypersaline streams, and endorreic and karstic complexes.

We propose an objective method for assessing the vulnerability of species and for prioritizing species and populations for conservation, especially insects. Species of water beetles from two Spanish provinces of the southeast of the Iberian Peninsula were ranked according to their conservation priority at the local, national and global levels taking into consideration a set of six variables: general distribution, endemicity, rarity, persistence, habitat rarity and habitat loss. Each variable was categorized into four ranks (0–3) of increasing risk for survival. Ochthebius glaber , Ochthebius irenae , Ochthebius montesi , Ochthebius albacetinus and Hydraena mecai were seen to be the most vulnerable, for which reason we propose they should be included in the national red list. Furthermore, O. glaber , O. irenae and O. montesi are proposed for inclusion in the IUCN red list as “Vulnerable”. These species are Iberian endemisms, with geographic ranges restricted to the southeast, and are threatened by habitat loss. Effective protection of these species requires measures directed at the conservation of their habitats. Crucial target habitats for protection in the southeast of the Iberian Peninsula include freshwater streams at medium altitudes, saline streams and endorreic lagoons.

1. In this work, carried out in the province of Murcia, a representative semi-arid area of the Iberian Peninsula, water beetles were used as indicators to identify the aquatic ecosystems with the highest interest for conservation. For that purpose, an iterative algorithm of complementarity based on the richness of aquatic Coleoptera was applied. ‘Complementarity’ refers to the degree to which an area, or set of areas, contributes otherwise unrepresented attributes to a set of areas. This principle was used to maximize the number of species represented within a given number of areas. 2. Only the species subsets whose taxonomic status, presence and distribution in the study area are well known were used. In total, 146 species were included, of which 12 are Iberian endemics and 32 are rare species (found only in one grid cell in the study area). 3. The highest correlation was generally shown by species richness with endemic, rare and vulnerable species richness. Thus, basing conservation strategies on species richness appears to be an effective protocol. 4. To preserve the highest degree of biodiversity in the aquatic ecosystems of the study area, the following need to be protected: (a) headwater streams in the north west of the province; (b) the uppermost reaches of the Segura River; (c) hypersaline and coastal ramblas; (d) rock pools and coastal ponds. 5. The present network of Protected Natural Spaces in the study area does not include many of the aquatic ecosystems shown to have the highest biodiversity of beetles. However, the future European ‘Natura 2000’ network will protect the 10 grid cells of highest aquatic biodiverstity, or at least part of them. Copyright © 2004 John Wiley & Sons, Ltd.

The main goal of the present study was to develop an ecological integrity index for littoral wetland management and conservation in semiarid Mediterranean areas that have been highly impacted by agriculture, including the selection of pressure and state indicators at landscape and wetlands scales that reflect the status, condition, and trends of wetlands ecosystems. We used a causality framework based on the relationship between pressure of anthropogenic activities and the ecological state of wetlands and their catchments, integrating environmental, biologic, economic, and social issues. From the application of 51 indicators in 7 littoral wetlands in the southeastern Iberian Peninsula, we selected 12 indicators (5 at catchment scale and 7 at wetland scale) to constitute the ecological integrity index proposed. The potential nitrogen export per area at catchment scale and the potential relative nitrogen export from the area surrounding the wetlands were the best pressure single predictors of state indicators with a causal relationship with environmental meaning. Wetlands in catchments with more agriculture had less ecological integrity than those in less impacted areas. A wide riparian zone in some wetlands acts as a buffer area, diminishing the effects of intensive agriculture. The index of ecological integrity developed here has a number of essential characteristics that make it a useful tool for ecosystem managers and decision-makers. The index can be used to (1) assess and control ecological integrity, (2) diagnose probable causes of ecological impairment, (3) establish criteria for protecting and restoring wetland ecosystems, and (4) integrate catchment management.

Summary 1. Primary production by Chara vulgaris and by epipelic and epilithic algal assemblages was measured in a semiarid, Mediterranean stream (Chicamo stream, Murcia, Spain) during one annual cycle. 2. The rates of gross primary production (GPP) and community respiration (CR) were determined for each algal assemblage using oxygen change in chambers. The net daily metabolism (NDM) and the GPPd−1 : CR24 ratio were estimated by patch-weighting the assemblage-level metabolism values. 3. Gross primary production and CR showed significant differences between assemblages and dates. The highest rates were measured in summer and spring, while December was the only month when there were no significant differences in either parameters between assemblages. GPP was strongly correlated with respiration, but not with algal biomass. 4. Chara vulgaris showed the highest mean annual metabolic rates (GPP = 2.80 ± 0.83 gC m−2 h−1, CR = 0.76 ± 0.29 gC m−2 h−1), followed by the epilithic assemblage (GPP = 1.97 ± 0.73 gC m−2 h−1, CR = 0.41 ± 0.12 gC m−2 h−1) and epipelic algae (GPP = 1.36 ± 0.22 gC m−2 h−1, CR = 0.39 ± 0.06 gC m−2 h−1). 5. The epipelic assemblage dominated in terms of biomass (82%) and areal cover (88%), compared with the other primary producers. Epipelic algae contributed 84% of gross primary production and 86% of community respiration in the stream. 6. Mean monthly air temperature was the best single predictor of macrophyte respiration and of epipelic GPP and CR. However, ammonium concentration was the best single predictor of C. vulgaris GPP, and suspended solid concentration of epilithon GPP and CR. 7. Around 70% of the variation in both mean GPP and mean CR was explained by the mean monthly air temperature alone. A multiple regression model that included conductivity, PAR and nitrates in addition to mean monthly air temperature, explained 99.99% of the variation in mean CR. 8. Throughout the year, NDM was positive (mean value 7.03 gC m−2 day−1), while the GPP : CR24 ratio was higher than 1, confirming the net autotrophy of the system.