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This study analysed and compared the shell shape, morphometrics and relative growth of four sympatric limpet species (Patella depressa,Patella ulyssiponensis,Patella vulgataandSiphonaria pectinata) collected at Praia da Luz in Lagos (Algarve coast – southern Portugal). Morphometric relationships were established through regression analysis between linear (shell length, width and height), ponderal (total weight), area (shell base and surface areas) and volume variables (shell internal and total volumes). Relative growth (isometryvsallometry) was analysed to assess variation in the growth rate of morphometric variables throughout the species ontogeny. In addition, morphometric indices (ellipticity, conicity, density, surface area and volumetry) were calculated to further characterize shell shape. Overall, 1482 individuals with broad size and weight ranges were analysed (P. depressa= 354;P. ulyssiponensis= 306;P. vulgata= 408;S. pectinata= 414). All regressions were highly significant (P< 0.001) and the morphometric variables were strongly correlated (r= 0.761 to 0.994). Among 28 morphometric relationships, there were 14 isometries, 13 positive allometries and only one negative allometry. The morphometric indices revealed clear morphological differences between species and were mostly size-dependent, reflecting gradual changes in shell shape during growth. The main results are compared with a compilation of analogous data reported for these limpet species throughout their distributional range. Overall, the general trends in relative growth are discussed in terms of the species life habits, main traits and functional morphology.

This study describes Apseudopsis formosus sp. nov., a new apseudomorph tanaidacean species from the Ria Formosa lagoon (southern Portugal). Species description was based on 223 individuals (22 juveniles, 60 males and 141 females), comprising diverse developmental stages (juveniles II, males I and II, preparatory, copulatory and intermediate females). The total length of the studied population ranged from 2.2 to 3.0 mm in juveniles, 2.5 to 4.8 mm in males and 2.9 to 4.9 mm in females. Overall, Apseudopsis formosus sp. nov. differs from congeneric tanaidaceans from the Atlantic Ocean and Mediterranean Sea by the presence of combined different morphological characters such as short pointed rostrum, posterolateral pointed corners on pereonites 2-6, hyposphenium only on pereonite 6, antennular outer flagellum 7- to 10-segmented, inner flagellum 3-segmented and five spines on propodus of pereopod 1, and sexual dimorphism evidenced by a pronounced mid-dorsal triangular wing-shaped protuberance on male merus cheliped, unique in Apseudopsis genus. At each studied developmental stage, some individuals presented abnormalities in spination, having only four spines in one of the propodus of pereopod 1. Additionally, five first records of Apseudopsis from the Algarve coast (A. adami, A. bacescui, A. elisae, A. mediterraneus and A. uncidigitatus) are reported for Portuguese waters. A biogeographic overview of the genus Apseudopsis is presented through the compilation and mapping of all worldwide reported occurrences. Passive dispersion can explain the most recent species distribution, yet not disregarding that the study area is taxonomically understudied. This study contributes to improve the current knowledge on tanaidacean taxonomy and updates the geographical distribution range of the Apseudopsis-complex. Portuguese Fisheries Operational Programme (Mar2020) [MAR-02-01-02-FEAMP-0061] European Maritime and Fisheries Fund (EMFF 2014-2020) Fundacao para a Ciencia e a Tecnologia (FCT)Portuguese Foundation for Science and Technology [SFRH/BPD/94985/2013] Centro de Estudos do Ambiente e do Mar (CESAM) [UID/AMB/50017] FCT/MEC FEDER, within the PT2020 Partnership Agreement FEDER, within Compete 2020European Union (EU)

This study describes the reproductive cycle of the common limpet (Patella vulgata) and rough limpet (Patella ulyssiponensis) from the Algarve coast (southern Portugal). Individuals of both species were sampled monthly during two consecutive years, and subjected to gonad histology and calculation of the mean gonadal index (GI). Both species had balanced sex ratios (P. vulgata = 1M: 0.98F; P. ulyssiponensis = 1M: 1.03F), similar size-frequency distribution between sexes, and equivalent mean shell lengths (SL) and total weights (TW) between males and females. In these protandrous hermaphrodites, the estimated size at sex change was slightly smaller in P. vulgata (SL50 approximate to 29 mm) than in P. ulyssiponensis (SL50 approximate to 36 mm). The reproductive cycles of both species were characterised by a main spawning season in early spring to early summer, sometimes including subsidiary spawning events. A comparison of the main spawning season throughout the species distributional ranges revealed that populations of P. vulgata and P. ulyssiponensis from southern Portugal have later spawning periods than other populations from the northeastern Atlantic Ocean. The present information is relevant for conservation purposes and for the proposal of management measures for the harvesting activity targeting P. vulgata and P. ulyssiponensis in southern Portugal. Agência financiadora Fisheries Operational Programme (MAR 2020) European Maritime and Fisheries Fund (EMFF 2014-2020) Corporation Bank of India info:eu-repo/semantics/publishedVersion

Ocean acidification (OA) will decrease shellfish growth and survival, with ecological and economic consequences for fisheries and aquaculture. However, the high variability of results among experiments, and the lack of long-term studies, make it difficult to predict the effect that OA will have on bivalve species. We tested the long-term effect of high CO2 on growth, calcification rates, and survival of juveniles of the commercial bivalve species Chamelea gallina from Southern Portugal. The local high alkalinity of seawater probably buffered the negative effect of the pH drop, and after 75 days juveniles increased their growth and calcification rates with CO2. However, after 217 days, the situation reversed, bivalves under control conditions had the highest growth and calcification rates, while individuals under high CO2 presented negative calcification rates. The biometric variable that responded first was the width of the individuals, followed by the height and length of the shells. Survival was unaffected except for a mortality peak of juveniles under control and intermediate conditions as a consequence of a temperature drop. In the short term, C. gallina will increase their calcification rates to compensate for OA. However, in the long term, the additional energy expended will be translated into growth losses with negative repercussions for the fisheries and aquaculture. The cultivation of shellfish on high alkaline seawater should be further explored as a bioremediation measure to mitigate the negative effect of OA on shellfish aquaculture.

This study reports the reproductive cycle, condition index, size at first maturity, growth and the morphometric relationships of the common cockle Cerastoderma edule in Ria de Aveiro (NW Portugal), fundamental knowledge in fisheries management planning and ecosystem conservation. The reproductive cycle was monitored for a period of two years, from January 2013 to December 2014. Spawning extended from June to October, with a peak in the summer months (July to September). The condition index showed a seasonal pattern which appear related to food availability and gametogenic cycle. Sexual maturity was attained at a shell length of 18.6 mm during the first year of life, which stands below the minimum landing size currently in force (25 mm). The von Bertalanffy growth equation was based on size-at-age data obtained from the microscopic analysis of growth rings in sectioned shells: Lt = 40.7[1-e −0.74(t-0.30)]. The morphometric relationships between shell dimensions (length, height and width) were studied in order to understand the effects of ontogenetic changes in cockles` shell morphology, an information that is useful to improve the selectivity of the fishing gears and the size-sorting devices. Some management strategies for the Ria de Aveiro cockle fishery were proposed.

Understanding the diversity and community composition of marine communities in coastal areas is of utmost importance to understand how overlapping anthropogenic pressures impact the marine environment. The demersal and epibenthic communities of the Portuguese northern continental shelf were surveyed using a bottom trawl to understand their taxonomic composition, abundance, spatial distribution, and their relationship with environmental variables such as sediment, organic matter, depth and latitude. Bottom sediments were homogenous, being mainly composed by sand particles. The diversity of the study area was low, but high abundance of important commercial species, as Trisopterus luscus, Trachurus trachurus, Palaemon serratus and Merluccius merluccius, in the juvenile stage of life, points out the importance of the area as nursery grounds. Four assemblages were identified, with a visible geographical pattern. Results obtained supply background information that may contribute to the development of future management and monitoring plans for this important and sensible coastal area. Project PRESPO 2008-1/038; PD/BD/135065/2017 info:eu-repo/semantics/publishedVersion

Coastal bivalve populations are characterized by large temporal fluctuations, driven by recruitment success dependent on environmental conditions. The present study evaluated the relationship of rainfall, chlorophyll-α, sea surface temperature (SST) and wind, with the biomass of four commercial bivalve species (Spisula solida, Donax trunculus, Chamelea gallina and Ensis siliqua) that occur both along the Barlavento (western region), and the Sotavento (eastern region), along the South coast of Portugal, between 1999 and 2011. Multiple regression models were used to test two hypotheses: a) the association between environmental conditions three months prior to the spawning period and the biomass in the following year (response variable) and b) the association between environmental conditions during the spawning season plus one month and the biomass in the following year. Wind was not included in the model to test a). The environmental variables considered were not important for E. siliqua. In the period prior to spawning, temperature was significant for S. solida (both study areas), rain for D. trunculus and C. gallina (western area) and chlorophyll-α for C. gallina (western area). All the correlations were positive. During the spawning period, rain was significant for all three species but with different trends. The correlation with rain in months early in the spawning season was positive for S. solida (both areas) and D. trunculus (western area). The correlation with the rain in months towards the end of the spawning period was negative for D. trunculus, and C. gallina (western area). Chlorophyll-α in months at later stages of spawning was significant and positive for D. trunculus (both areas) and C. gallina (western area). The wind, expressed as an index developed to indicate the overall occurrence of winds blowing parallel to the coast (assumes to favour the retention of larvae in appropriate environments), was negatively correlated with biomass for mid to late spawning season for S. solida (eastern area) and D. trunculus (western area). For C. gallina there was a positive correlation with wind early in the spawning season. The SST was not an important variable during the spawning period with the exception of D. trunculus where the temperature at mid spawning season was significant with a negative correlation in the western coast and positive in the eastern coast. This study highlighted the annual spatial distribution of four commercially important bivalves and how environmental factors are likely to play an important role on both biomass and location of the fishing beds. Monitoring of the environmental variables could provide information to predict biomasses of bivalve species, an important tool for its management, as well as predict trends and plan strategies in response to global environmental changes. info:eu-repo/semantics/publishedVersion

The epifauna associated to farmed mussels in southern Portugal coast was analysed, aiming at identifying the species with spreading potential through commercial transport. The presence of a relevant number of the species here found is not reported to at least one of the common mussel export/transposition countries. Indeed, important species biogeographic dissimilarities between the mussel farm area and the Greater North Sea and Western Mediterranean Sea sub-regions were detected, suggesting the potential transport of non-indigenous species (NIS) into other countries. Among them, fouling species such as the anemones Paractinia striata and Urticina felina, the acorn barnacles Balanus glandula and Balanus trigonus or the bryozoans Bugulina stolonifera and Schizoporella errata exhibit functional attributes that allow them to colonise and spread in new areas. This combined biogeographic and functional approach may contribute to clarify the role of aquaculture on the transport of NIS and to predict and prevent their spreading worldwide. info:eu-repo/semantics/publishedVersion

This study analysed the shell morphology, morphometric relationships and relative growth in three topshell species (Phorcus lineatus, Phorcus sauciatus and Steromphala umbilicalis) collected in the Algarve coast (southern Portugal). A total of 1382 individuals were sampled (465 P. lineatus, 447 P. sauciatus and 470 S. umbilicalis) and all species comprised individuals with broad size and weight ranges. Morphometric relationships were established between linear (shell height, width, spire height, aperture height, aperture width) and ponderal (total weight) variables, whose relative growth (isometry vs. allometry) was analysed to assess variation throughout the species ontogeny. All morphometric relationships were highly significant (P < 0.001) and displayed invariably high correlation coefficients (r = 0.828 to 0.977), presenting mostly negative allometries (77.8%), distantly followed by positive allometries (16.7%) and by isometric growth (5.5%). In addition, four morphometric indices (sphericity, conicity, aperture roundness and density) were calculated to further describe and discern variation in shell shape in these topshell species. Moreover, this study provides a useful compilation and comparison of morphometric relationships, indices and relative growth features, thus improving the knowledge currently available on these subjects for P. lineatus, P. sauciatus and S. umbilicalis. IPMA-2019-042-BI info:eu-repo/semantics/publishedVersion

Populations of marine bivalves are subject to large interannual fluctuations as a result of their sensitivity to unfavourable environmental conditions. These populations have a strong dependence on recruitment, which constitutes a risk to stock conservation and the sustainability of the commercially exploited species. Bivalve sanctuaries comprising no‐take areas can promote the restocking of large coastal areas as a result of the high fecundity and the potentially long‐distance larval dispersal of bivalves. The present study explores a novel spatio‐temporal approach to investigate suitable locations for bivalve sanctuaries, aimed at protecting and enhancing stocks along the Algarve coast in southern Portugal. In the context of small‐scale fisheries, bivalve dredging constitutes an important socio‐economic activity. Three bivalve species are targeted: the striped venus (Chamelea gallina), the donax clam (Donax trunculus), and the surf clam (Spisula solida). Data gathered from 36 bivalve fishing surveys conducted over three decades (1986–2015) were analysed using geostatistical methods, accounting for temporal and spatial autocorrelation to produce continuous prediction maps of species distribution for each survey. The approach taken permitted the use of all scattered historical data collected by different methods. The predictions were then used to summarize and illustrate the spatial distribution of species across time, in terms of average biomass, variability, and maximum potential biomass, and to delimit the areas as a function of the species persistence (recurrent, occasional, or rare). The temporal patterns through space were further investigated using empirical orthogonal function (EOF) analysis. The areas accounting for 80% of the species biomass were also estimated. Results of this set of analyses led to the proposal of locations for establishing bivalve sanctuaries, aimed at enhancing the stocks of commercial bivalve species in the long term. Such an innovative spatio‐temporal approach and management strategy is replicable in other fishing resources and geographic areas.

In this study, the genetic diversity of Donax vittatus across the Iberian Peninsula was investigated using four mitochondrial (COI, Cytb, 16S F and M types) and three nuclear (H8, 18S and 285) genes. These same molecular markers were also sequenced in D. semistriatus and D variegatus to address the phylogenetic relationships of the species of the genus Donax common along the European coasts. Our results showed high haplotype diversity in combination with a low nucleotide diversity and a star-shaped network with a predominant haplotype, indicating a recent population expansion for the examined sampling sites of D. vittatus. Furthermore, analyses of population differentiation performed with COI mitochondrial marker, including global Far estimation and pairwise Far values, indicated the non-existence of significant genetic structure in D. vittatus of Northwest Iberian populations. Because these localities show a high genetic similarity, we suggest that D. vittatus could be a potentially alternative exploitable resource, as complement to the D. trunculus fisheries, whose natural stocks have decreased dramatically in some areas. Furthermore, we present for the first time, evidence of DUI in the clams D. vittatus and D. semistriatus. (C) 2017 Elsevier Ltd. All rights reservd. Ministerio de Economia y Competitividad [AGL2016-75288-R AEI/FEDER] Northern Regional Operational Programme (NORTE), through the European Regional Development Fund INDITEX-UDC Portuguese Foundation for Science and Technology (FCT) [SFRH/BPD/108445/2015] [NORTE-01-0145-FEDER-000035] info:eu-repo/semantics/publishedVersion

The main objectives of this study were (i) to provide an updated age-length key for D. trunculus from Atlantic waters, and (ii) to evaluate population dynamics, the timing of recruitment and production parameters of the wedge clam Donax trunculus in two moderately exposed sandy beaches (the protected area of Donana National Park and the tourist destination of Isla Canela) along the littoral of Huelva (SW Spain). First an in-depth analysis of the shell and updated estimation of growth parameters of the intertidal D. trunculus population were performed between January 2014 and July 2015 using two different methods i) thin-layer cross section (TL) (ii) length-frequency distributions (LFD). Von Bertalanffy growth functions provided an asymptotic length of 46 mm (LFD) and 46.7 mm (TL) and growth constants of 0.48 (LFD) and 0.47 yr(-1) (TL) in Donana beach. In addition, several deformities as well as signs of shell repair were observed. Population dynamics analyses through length frequency distribution clarified the timing of recruitment (February-March and July). The mean annual biomass ((B) over bar) of intertidal populations of D. trunculus ranged between 3.03 (Donana) and 3.31 g ash-free dry mass (AFDW) m(-2) yr(-1) (Isla Canela). Individual production showed the highest value at 27 mm length (0.117 g AFDW m(-2) yr(-1)) and annual production (P) ranged between 3.40 (Donana) and 4.91 g (Isla Canela), resulting in renewal rate (P/(B) over bar) values between 1.03 and 1.61, respectively. The present results, together with information on environmental parameters, revealed clear differences in population dynamics and production between beaches related to the presence or absence of a protection figure. European Fisheries Fund info:eu-repo/semantics/publishedVersion

The present study reports the first record of the Monrovia doctorfish, Acanthurus monroviae (Steindachner, 1876) in the Algarve coast (southern Portugal). A female (257 mm TL) was caught 21 April 2016 off the beach of Olhos d’Agua by a small-scale fishing boat operating bottom-set gill nets at approximately 15 m depth. Morphometric and meristic parameters of the specimen are reported and compared with previous records of A. monroviae. This is the second occurrence of this tropical fish species in Portuguese waters and the second northernmost capture ever reported for the northeastern Atlantic. The present record is an additional example of tropicalisation of the ichthyofauna in temperate waters by a thermophilic tropical species. Indeed, although not established in the study area, A. monroviae found a suitable seawater temperature regime in southern Portugal and further expanded its distributional range along the Iberian coasts. For biogeographic purposes, all reported occurrences of this species in the northeastern Atlantic and Mediterranean (including very recent records and sightings) are compiled and mapped.

A multimetric approach was used to detect structural, compositional, and functional shifts in the underlying macrobenthic communities of an offshore mussel (Mytilus galloprovincialis) farm in a Portuguese Aquaculture Production Area. Sampling stations distributed inside and outside this area were used to evaluate sediment descriptors and macrobenthic samples collected before (April and September 2010) and after (June and September 2014) the initiation of mussel farming. Sediment fine fraction, organic matter content, and trace element concentrations were found to increase with depth, independently from the mussel farm. Moreover, the structure and composition of the macrobenthic communities were likewise structured by depth. Turnover was the dominant temporal and spatial pattern of beta diversity for all communities. Furthermore, the functional diversity of these communities was unaffected by the mussel farm. These results suggested that an offshore profile allowed hydrodynamic conditions to weaken the impact of mussel farming and highlighted the importance of conducting an integrative multimetric analysis when studying aquaculture impacts on benthic communities. FEDER Program through the project IAPAA "Avaliacao do impacto da area de producao aquicola da Armona no ecossistema costeiro e comunidades locais" (PROMAR project) [31-03-01-FEP-0014]

The present study reports six new and consecutive records of the Atlantic blue crab (Callinectes sapidus Rathbun, 1896) in the southern coast of Portugal. Specimens were caught during less than two months (22nd November 2018 - 18th January 2019) as bycatch of trammel nets operated by small-scale fishing boats in scattered locations along the Algarve coast and in the Ria Formosa lagoon. Four adult males (221-236 mm carapace width) and two adult females (191-207 mm carapace width) were caught at relatively shallow depths (1-6 m), on muddy and sandy bottoms in the Ria Formosa lagoon and in the Algarve coast. Morphometric parameters of the specimens are compiled and the respective occurrences are mapped for biogeographic purposes. These first three occurrences in the Algarve coast and the second, third and fourth records in the Ria Formosa lagoon, further supported by additional anecdotal evidences and recent sales at the wholesale market, reveal a rapid westward expansion and confirm the establishment of C. sapidus along the southern coast of Portugal. Possible sources of introduction and causes for the distributional expansion are evaluated. The potential impacts of this invasive species on local ecosystems and fishing/harvesting resources are discussed. Fisheries Operational Programme (MAR 2020) European Maritime and Fisheries Fund (EMFF 2014-2020) info:eu-repo/semantics/publishedVersion

Harvested populations of the sea urchin (Paracentrotus lividus) from the northwestern (Carreco) and southwestern (Aljezur) coasts of Portugal were surveyed to describe the species reproductive cycle and assess possible relationships with geographical location and seawater temperature. Individuals were sampled monthly to analyze gonad histology, mean gonadal index (GI), and gonadosomatic index (GSI) during 2 consecutive years (November 2010-November 2012). Both populations presented an annual reproductive cycle, with synchronous gonad maturation and gamete release between sexes. Gonad maturation occurred throughout autumn-winter, followed by a single but prolonged spawning season during spring-summer. The duration of the spawning season displayed a latitudinal gradient likely related to the north-south increasing trend in seawater temperature, with the northwestern population (Carreco) exhibiting a shorter spawning period compared to the southwestern population (Aljezur). The timing and duration of the spawning season was compared with several populations throughout the distributional range of P. lividus in the Atlantic Ocean and Mediterranean Sea. In the population from Carreco, the size at first sexual maturity (test diameter = 35.9 mm) was considerably smaller than the minimum conservation reference size (MCRS) of 50 mm test diameter legally established for P. lividus. This study confirms that sustainable exploitation depends on harvesters' awareness of and compliance with the MCRS and provides useful information for the eventual establishment of a closed season in the harvesting of P. lividus. Fisheries Operational Programme European Maritime and Fisheries Fund Fisheries Operational Programme European Maritime and Fisheries Fund

The Atlantic blue crab Callinectes sapidus Rathbun, 1896 is native in the western Atlantic, however it is a non-indigenous species across Europe since 1900, among other world regions. In this paper, we report the first occurrences of this species in the Ria Formosa lagoon and in the Guadiana estuary (SW-Iberian Peninsula, Europe) which occurred in 2016 and July 2017, respectively. We hypothesize that the introduction of this species into these ecosystems might be due to the expansion of the Guadalquivir estuary population through natural processes (larval advection, active movement), or due to unintended introduction events after being transported aboard fishing boats, or, less likely, through ballast water. Changes in Guadiana's river flow after the construction of the Alqueva dam might also explain the presence of another non-indigenous species in the Guadiana estuary. The hypotheses presented, regarding the introduction of the Atlantic blue crab into these ecosystems and of its co-occurrence with other decapod species, are framed in a broader context to serve as a future research framework. The use of the Atlantic blue crab as a new fishing resource is also proposed, namely if it is to be used exclusively by local communities and if no deleterious impacts upon other fisheries and the ecosystem occur from this new fishery. Agência financiadora / Número do projeto Delta Stewardship Council Delta Science Program 1167 Foundation for Science and Technology (FCT, Portugal) UID/Multi/04326/2013 European Regional Development Fund (COMPETE program-Operational Competitiveness Programme) FCT IF/00661/2014/CP1234 SFRH/BD/104209/2014 SFRH/BPD/108949/2015 Berkeley Research Impact Initiative (BRII) - UC Berkeley Library 16-01-04-FMP-0005 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/publishedVersion

The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (203% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in It philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters. (C) 2016 Elsevier B.V. All rights reserved. Fundacao para a Ciencia e Tecnologia (FCT) project "ECOAPPROACH" [PTDC/AAC-AMB/121037/2010] FCT [SFRH/BPD/69563/2010] "Estrutura de Missao para a Extensao da Plataforma Continental" (EMEPC)

This study reports the morphometric relationships and relative growth of 20 uncommon bivalve species collected along the Algarve coast (southern Portugal). Morphometric relationships were established between three linear variables (shell length, height and width) and one ponderal variable (total weight) and the relative growth between variables (isometryvsallometry) was analysed in order to assess their variation throughout ontogeny. In addition, morphometric indices (elongation, compactness, convexity and density) based on ratios of those linear and ponderal variables were calculated in order to further characterize morphologically the bivalve species. A total of 2512 individuals belonging to nine bivalve families were analysed, comprising specimens with broad ranges in both shell length (11.8–109.0 mm SL) and total weight (0.2–354.6 g TW). All morphometric relationships were highly significant (P< 0.001) and displayed invariably high correlation coefficients (r= 0.727–0.998). Among a total of 60 morphometric relationships, 27 isometries, 25 positive allometries and 8 negative allometries were registered. The morphometric indices displayed a remarkable variation among taxa, reflecting the high morphological diversity of these miscellaneous bivalve species. Discriminant analysis provided a spatial visualization of the species morphometric variables that further evidenced their main shape features, the distinctness between some species and families (e.g. Pharidae and Cardiidae) and the morphological resemblance among some species belonging to other families (e.g. Veneridae and Tellinidae). Overall, this information is useful and has practical application in diverse research fields, including studies on systematics and taxonomy, physiology, biology, ecology, fisheries assessment and management.

The reproductive cycle of Acanthocardia tuberculata (Linnaeus, 1758) was studied in M’diq Bay. The gonadal development was determined by means of standard histological techniques, mean oocyte diameters and a condition index. Rough cockle is a gonochoric species with synchronous gonadal development and spawning in males and females. The sex ratio obtained was not significantly different to 1:1. Gametogenesis began in late winter (November) coinciding with the temperature drop. In June, with increasing sea water temperature, most of the population was spent and resting oocytes appeared dispersed in the gonad. Resting stage occurred from August to October, during which time sex could not be determined in 100% of the population. A. tuberculata showed a clear seasonality in its gametogenic cycle, with one spawning peak per year in June. Quantitative measurements of 6318 oocyte diameters indicated the patterns of development observed in the qualitative staging. The results obtained revealed the direct influence of temperature on the reproductive cycle. First sexual maturity occurred at 42.77 mm shell length. The information gathered in this study allowed preliminary management measures to be suggested for the fishery of this species, including a closed season during the main spawning season (May-June) and the establishment of a minimum landing size (at least 50 mm shell length) for A. tuberculata from the Moroccan Mediterranean coast.

This study reports a detailed description of the bycatch, discards and survival rates in the cuttlefish (Sepia officinalis) trap fishery off the Algarve coast (southern Portugal). A total of 86 fishing surveys involving 6,311 cuttlefish traps were performed between May and September from 2009 to 2014. Bycatch species were caught in 1,037 traps (bycatch catchability rate of 16.4%), comprising 1576 individuals with an overall weight of 268.3 kg. During the study period, bycatch CPUEs were 12.5 ind./50 traps and 2.1 kg/50 traps, with bycatch rates of 21.1% by number and 15.9% by weight. Thirty-four species (89.5% of bycatch taxa) were discarded at sea, corresponding to discard rates of 19.5% by number and 11.1% by weight. The short-snouted seahorse, Hippocampus hippocampus (L.), was the third most abundant bycatch species (11.6% No.; 0.4% kg) and the second most discarded (12.6% No.; 0.6% kg), being invariably discarded live and undamaged owing its conservation status. This markedly seasonal small-scale trap fishery constitutes a locally important socio-economic activity during spring and summer, characterised by low bycatch and discard rates, complemented by high survival rates of discards. Agência financiadora Interreg IVB-Atlantic Arc Programme European Union (EU) Fisheries Operational Programme MAR 2020 European Maritime and Fisheries Fund EMFF 2014-2020 info:eu-repo/semantics/publishedVersion

Non-indigenous species (NIS) are increasingly widespread and abundant in coastal areas, hence being considered indicators to assess the environmental status of marine waters under the Marine Strategy Framework Directive. However, information on the effects of biological invasions on species composition and abundance is still scarce, particularly for soft-sediment benthic communities, which remain poorly understood. Therefore, the present study aimed at monitoring the benthic communities of two Portuguese estuarine systems, with a particular focus on NIS. Sampling surveys were conducted at the Tagus and Sado estuaries, in three different years. Invertebrate communities were collected at sampling stations located along the estuarine gradient, using a clam dredge, and several water and sediment parameters were measured at the same locations. NIS represented nearly one fourth (23%) of the total observed individuals across all years and estuaries, with Ruditapes philippinarum accounting for 22% of the total abundance across estuaries and years. Although both estuaries presented a similar total number of species (91 at the Tagus and 81 at the Sado), three-fold more NIS were identified at the Tagus estuary. The frequency of occurrence of the NIS Crassostrea (Magallana) gigas, Mya arenaria and Panopeus occidentalis increased significantly over the three years at the Tagus estuary and decreased significantly for Dyspanopeus sayi from 2015 to 2018. The Tagus and Sado estuaries presented distinct and diverse communities, with the abundance of R. philippinarum being eleven-fold greater at the Tagus estuary than at the Sado estuary. This study provides a baseline list of the NIS occurring in two of the main Portuguese estuarine systems, as well as an approach to estimate NIS abundance, richness, frequency of occurrence and community diversity. Although most studies on NIS impacts have focused on single species, the assessment of the environmental status of marine waters requires that overall impacts of NIS on marine ecosystems are determined. This study indicated metrics that are appropriate to evaluate changes in soft-sediment benthic communities associated to the introduction of NIS. Fundacao para a Ciencia e Tecnologia (FCT)Portuguese Foundation for Science and TechnologyEuropean Commission [UID/MAR/04292/2019] project CRASSOSADO project AQUASADO (Programa Mar 2020) project COCKLES (Interreg Atlantic) [EAPA_458/2016] project NIPOGES (Programa Mar 2020) project COASTNET [PINFRA/22128/2016] Direcao Geral de Recursos Naturais, Seguranca e Recursos Maritimos (DGRM) Instituto da Conservacao da Natureza e das Florestas (ICNF) [SFRH/BD/145746/2019]

The present study reports morphometric relationships and discusses the relative growth in the banded murex (Hexaplex trunculus) and the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (southern Portugal). A total of 11 morphometric parameters (eight linear variables: shell length, shell width, total aperture length, aperture length, aperture width, spire length, spire width and siphonal canal length; three ponderal variables: total weight, soft parts weight and shell weight) were analysed in both species. The analyses comprised numerous individuals of both sexes and with broad size ranges (H. trunculus: 10.7–82.8 mm shell length;B. brandaris: 14.6–107.7 mm shell length), fairly representative of the populations from the Ria Formosa lagoon. In general,B. brandarisexhibited greater morphological plasticity and higher variability in shell shape compared withH. trunculus. In both species, the vast majority of morphometric relationships displayed positive allometries, distantly followed by negative allometries and by isometries. AlthoughH. trunculusandB. brandarisare known to lack external sexual dimorphism, several morphometric relationships revealed significant differences in the type of growth between sexes, which should be further confirmed using more powerful techniques, such as geometric morphometric analyses of shell shape.

Although the bivalve dredge used on the Algarve coast (southern Portugal) is highly selective for the target species, in some periods of the year the bycatch can exceed the catch of the commercial species. The present study aimed to quantify the bycatch and discards, estimate damage and mortality, and propose management measures to minimize discards and mortality. A total of 15 fishing surveys (60 tows) were performed using two types of dredges (“DDredge” targeting Donax trunculus and “SDredge” targeting Spisula solida and Chamelea gallina). Of the 85257 individuals (392.4 kg) of 52 taxa that were caught, 73.4% belonged to the target species, 22.1% to commercially undersized target species and 4.5% to bycatch species. Bycatch rates were lower for SDredge (13.5% in number and 6.3% in weight) than for DDredge (46.0% in number and 32.9% in weight). Damage and mortality rates were also lower using SDredge (1.3% and 1.0% of the total catches, respectively) than using DDredge (4.0% and 2.8% of the total catches). Survival experiments revealed the diverse vulnerability of the taxa and confirmed the influence of the damage score on the mortality rate. The results gathered in the present study encourage the adoption of a bycatch reduction device to reduce both direct and indirect mortality., Aunque la draga de bivalvos utilizada en la costa del Algarve (sur de Portugal) es altamente selectiva para las especies objetivo, en algunos períodos del año la captura incidental puede exceder la captura de las especies comerciales. En este contexto, el presente estudio tuvo como objetivo cuantificar las capturas incidentales y los descartes, estimar el daño y la mortalidad, y proponer medidas de gestión para minimizar los descartes y la mortalidad. Se realizaron un total de 15 embarques (60 arrastres) utilizando dos tipos de dragas (“DDredge” dirigida a Donax trunculus y “SDredge” dirigida a Spisula solida y Chamelea gallina). En total, se capturaron 85257 individuos (392.4 kg) pertenecientes a 52 taxones, distribuidos entre especies objetivo (73.4%), especies objetivo por debajo de la talla legal (22.1%) y especies de captura incidental (4.5%). Las tasas de captura incidental fueron menores en SDredge (13.5% número y 6.3% peso) que en DDredge (46.0% número y 32.9% peso). Las tasas de daños y mortalidad también fueron menores usando SDredge (1.3% y 1.0% de las capturas totales) que usando DDredge (4.0% y 2.8% de las capturas totales). Los experimentos de supervivencia revelaron la diferente vulnerabilidad de los taxones y confirmaron la influencia del nivel de lesiones en la tasa de mortalidad. Los resultados del presente estudio fomentan la adopción de un dispositivo de reducción de capturas incidentales (BRD) para reducir la mortalidad directa e indirecta.

The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata. O destino de capturas acessórias rejeitadas ao mar é uma questão de grande interesse para a pesquisa e gestão das pescas. Foram realizadas experiências de sobrevivência para avaliar a capacidade de sobrevivência dos animais danificados e rejeitados durante as operações com ganchorra, uma draga utilizada na pesca de amêijoa (bivalves). Três espécies capturadas acidentalmente, dois peixes (Trachinus vipera; Dicologlossa cuneata) e um caranguejo (Políbio henslowii), foram recolhidos durante a triagem das capturas realizadas a bordo de um barco de pesca comercial que opera com ganchorra. Uma escala de pontuação arbitrária foi utilizada para quantificar o tipo e amplitude dos danos inflingidos nos organismos. A bordo, os indivíduos danificados foram colocados em tanques com água do mar, que foram posteriormente transferidos para o laboratório. Experiências de sobrevivência foram realizadas durante as 48h subsequentes. A espécie D. cuneata exibiu a menor mortalidade após 48 horas (54%), seguido do P. henslowii (65%) e T. vipera (81%). Apesar dos valores de mortalidade percentuais determinados, o número médio de indivíduos que morreram durante 15 minutos de arrasto (tempo de pesca comercial padrão) foi relativamente pequeno, 1.2, 3.24 e 11 para D. cuneata, T. vipera e P. henslowii, respectivamente. No entanto, quando esses números são extrapolados para toda a frota da ganchora o impacto desta prática sobre as populações das espécies estudadas pode ser significativo, particularmente para a D. cuneata.

The striped venus Chamelea gallina is an important commercial bivalve species in Europe. However, large inter-annual fluctuations in stock abundance and periodic recruitment failure threaten the biological and economic sustainability of this fishery. This study aimed to improve the knowledge of the reproductive cycle and reproductive strategies of this species from the Algarve coast (southern Portugal) in order to contribute to the establishment of management measures and to assess its potential for aquaculture. The reproductive cycle of C. gallina followed a seasonal cycle, significantly influenced by sea surface temperature and food availability. Gametogenesis took place in winter, coinciding with the phytoplankton bloom. Spawning occurred during summer, followed by a short period of sexual inactivity in autumn. Condition index did not reflect the reproductive cycle of C. gallina and generally, followed the same trend of chlorophyll a. Glycogen was positively correlated with gonadal index and chlorophyl...

The exploitation of the common octopus Octopus vulgaris in Portugal increased 50% in the last 20 years, largely motivated by the depletion of many fish stocks. Recently, the biomass of this fishery resource sharply decreased in some areas causing serious concern among local fishermen and an effort is underway to advise on novel and sustainable management measures. In this context, the octopus pre-recruit aggregations along the Portuguese coast are identified using georeferenced fishery-independent data, from autumn and winter sampling between 1996 and 2008. The relationships between pre-recruit aggregations and several environmental variables are analyzed to characterize their essential habitats (EFH). Pre-recruits are distributed throughout the Portuguese coast aggregated in 8 distinct recruitment grounds located on the middle-shelf at 11–19 km from the coastline, which are characterized by average bottom depths of 65–110 m and are associated to major rivers and lagoon systems. Within each season pre-recruit abundance is much higher in the south region, while pre-recruit aggregations on the northwest coast showed high inter-annual and seasonal variation driven by environmental variability. The western zone adjacent to Ria Formosa lagoon (southern coast) was identified as the main recruitment ground for O. vulgaris along the Portuguese coast. This is supported by the higher abundance of pre-recruits and by the recurrence of their presence in this area over the years analyzed, both in autumn and winter. The effects of physical variables on pre-recruit abundance modelled with generalized additive models (GAM) showed important regional differences. Bottom salinity and river runoff are the environmental variables that have most impact on pre-recruit distribution and abundance on the west coast, regardless of any seasonal effects. On the other hand, temperature imposes distinct seasonal and regional limitations on pre-recruit distribution, both on the NW and S regions. Pre-recruit preferential habitat is characterized by bottom temperatures of 14 °C, salinity values around 36.0, low precipitation (average

Polybius henslowii Leach, 1820, a Portunid crab distributed from the British Isles to Morocco and the Mediterranean Sea is caught in high densities by many types of fishing gear and frequently thrown back to the sea. Along the northern coast of Portugal, P. henslowii is an important species discarded in beam trawl fishery. There are no quantitative estimations of discards and very little is known about its biology, information that is needed to value this species. The present work was conducted from March 2007 to December 2010 in order to improve the current knowledge of the reproductive biology of P. henslowii. By-catches were registered aboard commercial vessels that volunteered to participate in the study. In that period P. henslowii represented 57.3% of the total catch and was present in all hauls analysed. The target species, Palaemon serratus (Pennant, 1777), represented 1.2% of the total catch, showing the low selectivity of the fishing gear and the need for suppression of this gear to catch this shrimp species. Differences in size between sexes were found, with males being larger and heavier than females. Mature females occurred mainly in autumn and the carapace width at which 50% of the females reach maturity was estimated to be 37.8 mm, which could be set as the minimum landing size of this potential exploitable resource. A macroscopic ovarian maturity stages classification was proposed, allowing a rapid field assessment of female sexual maturity. This study fills a gap in the knowledge of a very important species discarded in beam trawl fishery that may be basis of further work.

The sword razor clam Ensis arcuatus is the most important commercial species of razor clam in Spain, and its fishery in the Ria de Pontevedra (Galicia, NW Spain) is the most productive. Despite the economic importance of this species, information on its biology is scarce. This study reports shell morphometric relationships, age, and growth rates of E. arcuatus in three fishing beds in the Ria de Pontevedra (Brensa, Bueu and Ons, located in respectively the inner, middle and outer zones of the ria), providing the first estimates of growth parameters for the species in the Iberian Peninsula. Growth was estimated by examination of surface growth rings and internal shell microgrowth patterns (acetate peel technique) that proved to be the most suitable method for growth estimate. Growth of E. arcuatus was slower in Bueu ( L ∞ = 140.4, k = 0.40) followed by Brensa ( L ∞ = 151.91, k = 0.40) and Ons ( L ∞ = 172.7, k = 0.33), and the clams reached commercial size in 1.7, 2.3 and 2.8 years in Ons, Brensa and Bueu, respectively. The differences in growth between sites in relation to environmental parameters are evaluated and the implications for the razor clam fishery are discussed.

The present study aimed to describe the reproductive cycle and estimate the size at sexual maturity of the Manila clam (Ruditapes philippinarum) in the Tagus Estuary (Portugal). Specimens were collected monthly from September 2013 to December 2015 during fishing surveys using bivalve dredges. The gametogenic cycle was described in detail using gonad histology and monitored throughout the study period by the monthly variation in the frequency of gonad maturation stages, mean gonadal index and mean oocyte diameter. This invasive population of R. philippinarum displayed synchronous gonadal development between sexes, with ripening occurring mainly in April and May followed by an extensive spawning period until November–December. Individuals reached the size at first sexual maturity at 29.4 mm in shell length (i.e. before 1 year old). Furthermore, the reproductive strategy, dynamics and potential were compared between the invasive R. philippinarum and the native congeneric carpet shell clam (Ruditapes decussatus). Overall, the data gathered in this study constitutes valuable baseline information to propose conservation strategies and implement management measures to minimize the harmful impacts caused by this invasive species on local ecosystems and native biodiversity, particularly over populations of autochthonous bivalves.

Noticeable changes in global temperatures, climate and ocean carbon chemistry are the result of carbon dioxide increase in the atmosphere. This increase has been mitigated by the oceans capacity to absorb one-fourth of the carbon dioxide in the atmosphere, although this CO2 intake affects oceans carbonate chemistry [i.e., ocean acidification—(OA)]. The detrimental effect of OA in the development and shell formation has been studied in several species of bivalves, although no information is available on the wedge shell Donax trunculus, a gastronomically appreciated species and an important economical resource in several southern European countries. We evaluated the effect of pCO2 increase on hatching and early life stages of D. trunculus, considering two ocean acidification scenarios (ΔpH −0.3 and ΔpH −0.6). Our results showed that elevated pCO2 caused a delay in hatching into D-larvae and reduced larvae survival. In the extreme scenario (ΔpH −0.6), some trochophore larvae persisted to day 9 of the experiment and more abnormal larvae were produced than in the ΔpH −0.3 and control treatments. At day 5, normal veligers under extreme acidification were smaller than in other treatments, but by day 9, these differences were attenuated and the average size of normal D-larvae varied inversely to the pH gradient. Possible underlying mechanisms for these complex response patterns are discussed, including the existence of phenotypic plasticity or genetic pre-adaptive capacity in this D. trunculus population to cope with future environmental changes.

The pullet carpet shell Venerupis corrugata is an economically valuable species in several European countries, however, nowadays stocks are under high fishing pressure. Hatchery production of juveniles for release is a major contributor to strengthen the stock and consequently improve the sustainability of the natural stocks. This study aimed to determine the feasibility of rearing V. corrugata larvae with different larval densities (10, 40 and 200 larvae per mL) in a recirculating aquaculture system (RAS), compared with the traditional larval rearing methodology (Batch). The mean survival, growth and metamorphic rate of V. corrugata larvae in RAS was higher (11.1%; 71.3m; 21.6% respectively) than in the Batch system, in all tested densities. The larval growth was not affected by the initial density until 40 larvae per mL, however, 200 larvae per mL decreased the larval growth in length nearly 54m. The larval rearing time was shortened in 2days in the RAS system. The physical, chemical and microbiologic parameters suggested that the tested densities were not excessive to disturb the biofilter stability of RAS. The V. corrugata larval rearing performed at high larval stocking densities in RAS system present a reduction in the operating costs to produce this species. Marinaqua (PROMAR) and Reproseed (FP7-KBBE-2009) project and acknowledge Ciência 2008 program (FCT).

The surf Spisula solida and the striped venus Chamelea gallina clams support important fisheries in Europe. These fisheries have been affected by inter-annual fluctuations in stock abundance and recruitment failures. Aquaculture could contribute to address these problems through the production of larvae or juveniles for stock-enhancement programmes. In the present study, the prerequisites to produce these species in hatchery were established. Of the different methods used to obtain gametes (thermal stimulation, scarification and flow through), C. gallina spawned in the flow through only. By its turn, the best method for obtaining gametes for S. solida was stripping. Higher survivals of D-larvae were found at 15 and 17 degrees C. The greatest larval survival and growth rates were obtained from larvae fed Isochrysis aff. galbana (T-iso). First C. gallina and S. solida pediveliger larvae were found at day 8 and day 26 respectively. The presence of metamorphosed larvae found even in the unfed treatment for C. gallina and for S. solida is an advantage for aquaculture production. After metamorphosis, the S. solida juveniles' survival was quite low, whereas there was no mortality for C. gallina juveniles reared without substrate regardless the diet provided. Juveniles fed the binary diet (Chaetoceros calcitrans - C. cal + T.iso) and the monodiet T-iso showed relatively higher growth in shell length and weight than C. cal. The hatchery production of these two species was possible, however the results of this study showed that C. gallina can be more attractive for aquaculture than S. solida.

European Council Regulation 104/2000 states that fishery products must be labeled to indicate commercial designation of species, the production method, and the catch area. Therefore, traceability of seafood implies knowledge of the species offered to retail and their origin. Ensissiliqua is a bivalve intensively fished in Europe and sold in fresh and canned forms. Although several published methods clearly differentiate Ensis genus species, none of those assess the origin of the commercial samples. In the present study, a microsatellite marker (Esi-UDC3055F) was developed to establish the catch area of E. siliqua samples. Amplification yielded a fragment of 275 or 302 base pairs, depending on whether they were Iberian or Irish populations. The usefulness of this method was also assessed in commercial samples. The results of this study provide a reliable methodology for the identification of catch area in European E. siliqua commercial samples. The coupling of this methodology with existing techniques for razor clam species identification provides a powerful tool for traceability and labeling enforcement.

This study estimated the age of Hexaplex trunculus (Gastropoda: Muricidae) by analysing operculum growth marks. Surface striae and adventitious layers were counted in opercula of H. trunculus from the Ria Formosa Lagoon (southern Portugal) and from the Bizerte Lagoon (northern Tunisia), and in aquacultured individuals used for validation of the ageing technique. Operculum growth features were also compared between H. trunculus populations under contrasting environmental conditions (namely seawater temperature). Despite high inter-individual variability, all H. trunculus populations displayed a clear increasing trend in the number of striae and layers with increasing specimen size. The operculum marginal growth revealed that opercular deposition is not annual. Instead, a few growth marks are formed in the operculum each year, which was confirmed with reared specimens. In both ageing methods, considerable variation in the number of counts at a determined shell length indicates that operculum growth marks should be interpreted cautiously because they might not correspond accurately with individual age. Because of the subjectivity inherent to either method, counting striae and layers in opercula only provides rough age estimates of H. trunculus. published

The present study provides updated information on amphipod assemblages of the southern Portuguese coast, the most south-western part of continental Europe. The influence of depth and sediment type on the spatial distribution of shallow soft-bottom amphipods was tested by means of univariate and multivariate methods. Samples were collected down to 40 m depth within areas ranging from very fine sand to gravel. The ratio between density and diversity was found to increase with depth and from coarser to finer sediments. Both physical variables tested were found to play a major role in structuring amphipod assemblages. However, some dominance of depth was evident as samples were mainly separated according to this variable. Moreover, while only 15 taxa were common to all depth levels, 35 were collected from all sediment types. Both depth and sediment type may override the potential effects of geographical location, as samples from different areas along the southern Portuguese coast were biologically related. A peculiar habitat was sampled in this study: a maerl bed, which was confirmed to be a hotspot of density. Nevertheless, this habitat did not harbor a distinct amphipod assemblage but some taxa such as Caprella spp., Lembos websteri, lysianassids and Gammarella fucicola were preferentially collected there. The biogeographical analysis pointed out the occurrence of 8% of Mediterranean endemic species, confirming the influence of the Mediterranean Sea beyond the Strait of Gibraltar, and the Atlantic-Mediterranean feature of the amphipod fauna of this geographically relevant area. The present results support the need to interpret the spatial distribution patterns of marine species in relation to the combined effect of depth and sediment characteristics.

The present study reports the growth rate of the purple dye murex, Bolinus brandaris (Gastropoda: Muricidae), estimated from mark-recapture experiments. A total of 1067 specimens (shell length = 43.4±8.1 mm, range = 14.6−78.4 mm) were marked with Dymo® tape tags and released in a semi-intensive fish culture earthen pond. After a period at liberty ranging from almost two months to around two years, 288 individuals were recaptured (shell length = 67.4±6.2 mm, range = 45.3−88.6 mm), which corresponded to a recapture rate of 27.0%. At recapture, only one specimen had lost the tag (tag loss rate < 0.1%) and all remaining tags were intact and legible. Mean monthly growth rates were 0.9±1.0 mm in shell length, 0.4±0.5 mm in shell width and 0.7±0.7 g in total weight. Growth rates showed high inter-individual variability and an evident decreasing trend with specimen size. Comparison of growth rates with similar information available for other muricids confirmed that B. brandaris is a relatively slow-growing species. This provides valuable information for both fisheries management and for assessing the potential of B. brandaris as a candidate species for molluscan aquaculture.

Macrobenthic community changes were assessed in relation to different levels of fishing intensity following a before—after, control—impact experimental design with a control, a moderately impacted area, and a highly impacted area. Samples were collected before, immediately after, and 1, 2, 3, 7, 14, 30, and 120 days after fishing. Communities in fished areas showed short-term significant effects on abundance, number of species, biomass, and diversity 1–3 days after fishing, with fished areas presenting lower mean values than the control. The opposite pattern was found for the carnivore-to-suspension feeding ratio. The main taxonomic groups showed different responses to fishing. Only gastropod abundance and the abundance of the polychaete families Pectinariidae and Sabellidae showed persistent negative effects of fishing. The effects on these polychaete families confirms the sensitivity of sedentary and suspension feeders to fishing. Some variables presented slightly higher negative effects with f...

The karyotype of the common ragworm Hediste diversicolor (OF Muller 1776) (Poly- chaeta, Nereididae) was determined for the first time; it comprised 8 metacentric, 2 submetacentric and 4 subtelocentric chromosome pairs. In a few metaphases, we observed an easily distinguishable undersized supernumerary chromosome. Recent taxonomic revisions of the family Nereididae have highlighted the need for further studies in several genera. To understand the taxonomic relationships in this family, we carried out a comparative karyological analysis through multivariate analyses (prin- cipal component analysis and hierarchical cluster analysis), using morphological and structural fea- tures of karyotypes, between H. diversicolor and 10 other Nereididae species. This analysis showed the distinctiveness of H. limnicola, H. diversicolor and Nereis oligohalina, which could be explained by the presence of 3 or 4 morphological categories of chromosomes in these species. The remaining species presented more symmetrical karyotypes with only 2 morphological categories and were grouped in 2 main clusters, mainly due to different percentages of metacentric chromosomal pairs. This study highlights the importance of cytogenetics in taxonomic studies of polychaetes.

The sword razor shell Ensis siliqua (Linnaeus, 1758) is a bivalve with a high commercial value being appreciated in fresh and processed markets. However, the genetic studies carried out in populations of E. siliqua are scarce. In this work, the genetic variability and differentiation of the sword razor shell was assessed using PCR–RFLPs of a fragment of the 16S rRNA mitochondrial gene and random amplified polymorphic loci (RAPD) in nine localities from Ireland, Spain, and Portugal. In the 314 individuals examined for the mitochondrial fragment, 12 composite haplotypes were observed; meanwhile, a unique phenotype was observed for each of the 242 individuals analyzed with 61 RAPD loci. Two of the mitochondrial composite haplotypes accounted for the majority of individuals (89.81%) and showed a remarkably disjoint distribution between Irish and Iberian samples, with the exception of Aveiro which exhibited as the most frequent haplotype the same found in Ireland. The level of variability observed for each sample was generally correlated with both types of markers and the results obtained suggest the existence of a strong population differentiation between Irish and Iberian localities, except for the Portuguese sample from Aveiro which is surprisingly closer to Irish individuals, although it is probably highly differentiated.

16 pages, 5 figures, 2 tables, 1 appendix, [EN] Ecological aspects of 75 megabenthic bivalve species found on the south coast of Portugal (from Vila Real to Sagres) were studied based on the information provided by seasonal bivalve surveys from 2000 to 2007 (8600 hauls, simultaneously using a razor shell dredge and a clam dredge). Of the 75 species identified, 36 occurred less than 30 times, and thus were considered rare in the area. The remaining 39 bivalves were analysed according to their occurrence, bathymetric distribution, geographic preferences, seasonal preferences, burying-depth, beach exposure and river mouth proximity. All species belonging to the Pharidae and Solenidae families (razor shells) and most Tellinidae were significantly more frequent in the razor shell dredge (indicating deeper burying in the sediment), whilst the families Cardiidae and Donacidae were significantly more frequent in the clam dredge (indicating that these species are probably closer to the sediment surface). As for the season, most bivalve species occurred similarly in both seasons (19 sp; 49%), but a large proportion were more abundant during the autumn surveys (17 sp., 44%), whereas only three species were commoner during the spring surveys. Most species belonging to the families Cardiidae and Mactridae were commoner in the autumn surveys. The spatial distribution differed between species and cluster analysis identified four communities with greater geographic affinity. Species belonging to the family Cardiidae were preferably found in the western part (WB) and the eastern part (S) of the study area, whereas the families Donacidae, Mactridae and Tellinidae occurred mainly in the central area (EB) and the eastern (S) coastal sectors. Overall, shallower species (modal depth at 3-6 m) showed greater occurrences and abundances than the deeper ones, and the depth pattern observed did not change between seasons. Donacidae and Mactridae (except Mactra glauca) were represented essentially by shallow species, whereas Cardiidae (except Acanthocardia tuberculata and Cerastoderma edule) included mostly species occurring in deeper waters. Bathymetric sequence of species distribution within some families was observed, [ES] Se estudiaron algunos aspectos ecológicos de 75 especies de bivalvos megabentónicos en la costa meridional de Portugal (desde Vila Real a Sagres), basados en la información obtenida a lo largo de varios muestreos estacionales realizados entre el año 2000 y 2007 (8600 muestras). Las muestras se obtuvieron utilizando simultáneamente un rastro para capturar navajas y un rastro para capturar almejas). De los 75 taxones identificados, 36 aparecieron menos de 30 veces, considerándose raros en el área. De los 39 taxones de bivalvos restantes se analizaron los patrones de presencia, distribución batimétrica, preferencias geográficas y estacionalidad y se relacionaron con la profundidad de enterramiento, la exposición de las playas y la proximidad a desembocaduras de ríos. Todas las especies de las familias Pharidae, Solenidae (navajas) y la mayor parte de Tellinidae fueron más frecuentes en el rastro para capturar navajas, indicando una mayor profundidad de enterramiento en el sedimento, mientras que las familias Cardiidae y Donacidae fueron significativamente más frecuentes en el rastro para capturar almejas, indicando que estas especies se encuentran más cercanas a la superficie del sedimento. La mayoría de especies presentaron abundancias similares a lo largo de todo el año (19 especies, 49%), pero una gran proporción fueron más abundantes en los muestreos de otoño (17 especies, 44%), mientras que sólo 3 especies fueron más comunes en primavera. La mayoría de especies de las familias Cardiidae y Mactridae fueron más comunes en otoño. La distribución espacial fue distinta para cada especie y el análisis de clasificación jerárquica mostró 4 comunidades con mayor afinidad geográfica. Las especies pertenecientes a la familia Cardiidae se encontraron preferentemente en la parte occidental de la zona de estudio (WB) y en la oriental, mientras que las familias Donacidae, Mactridae y Tellinidae aparecieron principalmente en pelos sectores central (EB) y oriental (S) del área. Las especies de distribución más somera (profundidad modal 3-6 m) fueron más frecuentes y abundantes en general que las especies de más profundidad y este patrón no cambió entre primavera y otoño. Donacidae y Mactridae (excepto Mactra glauca) estuvieron representadas fundamentalmente por especies someras, mientras que los Cardiidae (excepto Acanthocardia tuberculata y Cerastoderma edule) estuvieron representados principalmente por especies de profundidad. En algunas familias se observó una distribución batimétrica secuencial, This work formed part of the MMR post-doc program financed by Fundação para a Ciência e a Tecnologia BPD/14935/2004

The present study was undertaken in order to analyse whether macrobenthic communities can or not be used in monitoring programmes of the environmental quality of fish ponds. Functional community analysis and biotic metrics were analysed aiming at the assessment of their effectiveness in discriminating potential impacts of fish production in these systems. The macrofaunal patterns in earthen fish ponds of the Ria Formosa lagoon showed to be influenced by the input of fish food during the production cycle and by changes in abiotic parameters caused by seasonality and fish production. Polychaetes were generally dominant considering the number of taxa and abundance. The trophic functional analysis of the benthic communities showed that the deposit-feeding functional group dominated in both areas of the ponds but within water entrance areas there was an increase of suspension-feeding, carnivory and herbivory feeding modes. The presence of less trophically mixed communities within feeding areas may be related to the relative high disturbance levels of these areas. From the biotic indicators that show a differential response to organic input in fish earthen ponds, the abundance of Capitella spp. as well as the diversity (Shannon–Wiener and Margalef species richness), evenness (Pielou) and AMBI indices seem to be the best indicators to be used in monitoring studies in similar systems. Managers should pay particular attention when Capitella spp. taxa are observed within the feeding areas. Nevertheless, manipulative experiments are needed in order to test the dominance levels of Capitella spp. and the values of those indices that are of concern.

This study aimed to assess the influence of growth and reproductive cycle on the meat yield and proximate composition of the banded murex (Hexaplex trunculus) from the Ria Formosa lagoon (Algarve coast, southern Portugal). Samples of the edible portion (all soft-body tissues) were analysed monthly during one year. The average meat yield was 37.9±4.6%, with females containing more edible content (39.1±4.7%) than males (36.8±4.2%). The proximate composition comprised 70.7±1.4% moisture, 20.1±1.2% protein, 1.6±0.3% fat, 3.0±0.3% ash, and 4.6±1.2% carbohydrate, corresponding to an energetic value of 119.2±7.5 kcal/100 g wet weight. The meat yield was influenced by specimen size, increasing significantly during growth. Both meat yield and proximate composition presented seasonal fluctuations related to the reproductive cycle, which coincided mainly with the periods of maturation and spawning of this species in the Ria Formosa. Finally, H. trunculus meat yield and proximate composition were compared with similar information available for other marine gastropods.

The age and growth of the smooth clam Callista chione from the southwestern coast of Portugal were estimated during a 1 yr study period by using both the surface growth rings and internal shell microgrowth lines (by acetate peel method). The von Bertalanffy growth curves obtained by these 2 methods were, respectively: Lt = 91.9(1 - e - 0.18 (t + 0.22) ) and Lt = 98.1(1 - e - 0.15 (t + 0.43) ). Based on these, the counting of surface growth rings is appropriate for a quick age estimation of individuals up to 10 yr old (~75 mm shell length, SL). For older specimens, analysis of the growth lines in the cross section of shells is recommended, because close to the shell border it becomes difficult to distinguish growth rings on the shell surface. Rapid shell growth occurred in spring and summer, whereas slow growth occurred during autumn and winter, with the deposition of an annual growth ring. The over- all growth performance and the phi-prime index were used to compare growth parameters with data from literature about venerid bivalves. These parameters indicated that Callista spp. have a higher growth performance than other venerid bivalves and this is correlated with geographical latitude. The smooth clam achieves sexual maturation at 4 yr of age and reaches the minimum landing size (60 mm SL) after 5 yr.

Despite the importance of the dredge fishery in Portugal, few studies have focused on bycatch and discard mortality. Catches from three types of dredge: north dredge (ND); grid dredge (GD); and traditional dredge (TD), currently used in the Spisula solida (Bivalvia: Mactridae) fishery, were compared in order to characterize bycatch and to estimate discard mortality. In TD and ND, the catch was retained in a net bag, whereas in the GD a metallic grid cage was used. Tows were carried out on sandy bottoms at depths ranging from 5 to 10 m. Bycatch differed significantly between dredges. The ratio of bycatch abundance to S. solida was 0.22:1 for ND, 0.10:1 for GD and 0.33:1 for TD. The weight ratio was 0.15:1, 0.14:1 and 0.32:1 for ND, GD and TD, respectively. Although a lower bycatch was observed for GD, higher mortality (ND: 10%; TD: 20%; GD: 36%) was estimated for this dredge. However, taking into consideration the fishing yields obtained for each dredge combined with the fact that this fishery is managed by daily quota per vessel, our results showed that, at daily quota level, discard mortality was lower when GD was used. Our study suggests that in output-controlled fisheries, there are obvious advantages in developing dredges with rigid retention structures, such as metallic grids, because these are more selective and efficient than dredges that use net bags. At species level, the bycatch mortality to attain quota varied among dredges. A "selective" and persisting significant removal of bycatch species from biota may change benthic community structure. Therefore, clam fisheries should apply exploitation strategies that are goal-oriented and adaptive to the evolution of the macrofauna communities, which might include the use of different dredge types, thereby diversifying the bycatch and consequently avoiding the cumulative removal of specific macrofauna taxa.

Luciferase-based imaging allows a global view of microbial pathogenesis. We applied this technique to gammaherpesvirus infection by inserting a luciferase expression cassette into the genome of murine herpesvirus-4 (MuHV-4). The recombinant virus strongly expressed luciferase in lytically infected cells without significant attenuation. We used it to compare different routes of virus inoculation. After intranasal infection of anaesthetized mice, luciferase was expressed in the nose and lungs for 7–10 days and in lymphoid tissue, most consistently the superficial cervical lymph nodes, for up to 30 days. Gastrointestinal infection was not observed. Intraperitoneal infection was very different to intranasal, with strong luciferase expression in the liver, kidneys, intestines, reproductive tract and spleen, but none in the nose or lungs. The nose has not previously been identified as a site of MuHV-4 infection. After intranasal infection of non-anaesthetized mice, it was the only site of non-lymphoid luciferase expression. Nevertheless, lymphoid colonization and persistence were still established, even at low inoculation doses. In contrast, virus delivered orally was very poorly infectious. Inoculation route therefore had a major impact on pathogenesis. Low dose intranasal infection without anaesthesia seems most likely to mimic natural transmission, and may therefore be particularly informative about normal viral gene functions.

Mate competition and mate choice are not mutually exclusive behaviors. Both behaviors may drive sexual selection in one or both sexes of a population. One of several factors affecting which behavior is exhibited by which sex is the operational sex ratio (OSR) in the study population. The present study combines behavioral observations in the field with controlled experiments in aquaria to investigate social interactions and mate choice in both male and female long-snouted seahorses Hippocampus guttulatus in the context of the population OSR. Compared with the more readily studied pipefishes, data on OSR and mate choice in seahorses are scarce in the published literature. Our field data provide novel evidence of social promiscuity, size-assortative mating, and an OSR that varies from being unbiased early and midseason to male biased at the end of the breeding season. Our mate choice experiments revealed intersexual differences in mate preference with males significantly preferring larger females to familiar ones. Taken together, our field and experimental results suggest that mate choice rather than intrasexual competition could drive sexual selection in seahorses. Key words: assortative mating, reproductive behavior, sexual selection, Syngnathidae. [Behav Ecol]

The purple dye murex, Bolinus brandaris (Linnaeus, 1758), is a muricid gastropod common throughout the Mediterranean and along the Moroccan and Portuguese Atlantic coasts. In the present study, we confirmed the diploid chromosome number of 2n = 70 for this species, and established for the first time the karyotype, which comprised 12 metacentric, 15 submetacentric and eight subtelocentric chromosome pairs. To facilitate cytotaxonomic comparisons, we carried out a comparative karyological analysis through multidimensional scaling between B. brandaris and three other 2n = 70 muricid species (Hexaplex trunculus, Ocenebra erinaceus, and Stramonita haemastoma) for which chromosomal measurements have been previously published. The interpretation of the ideograms and the statistical analysis highlighted the closest similarity of B. brandaris and H. trunculus compared to S. haemastoma and O. erinaceus. Indeed, B. brandaris and H. trunculus showed the smallest dissimilarities both for relative length and arm ratio, with O. erinaceus presenting intermediate values, whereas the highest dissimilarities were found between H. trunculus and S. haemastoma for both data. The karyotypes of B. brandaris and H. trunculus (subfamily Muricinae) presented the highest proportions of metacentric chromosomes compared to the other two muricids analysed, suggesting that those karyotypes could be considered primitive within the 2n = 70 Muricidae studied so far. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 185–193.

12 pages, 8 figures.-- Printed version published Dec 10, 2008., From 2000 to 2006, a total of 75 bivalve species were identified, varying from 29 (spring 2001) to 54 species (spring 2005) per year. Seasonal tendencies in diversity varied according the year, thus the interpretation of long-term and regional scales is essential before drawing any conclusions in other studies. Richness and diversity consistently decreased with depth and increased with sediment grain size (from low in very coarse sand to high in coarse silt). Diversity decreased progressively from 3 to 16 m depth, thus the harsher shallower environments (due to waves and tidal air exposure) showed greater diversity than the most stable areas. Communities in finer sediments were more diverse than those in coarser sand. Evenness showed patterns opposite to diversity, overall., Diversity and evenness maps (produced with multivariate universal kriging), showed that most geographic areas with greater diversity were farer from river outflows and wastewater treatment plants. Two types of geographic pattern were observed: areas with persistently greater bivalve diversity through time and areas that changed locally from year to year. This spatial analysis can be used to establish priority conservation areas for management purposes, and to analyse the persistency of regional diversity patterns. The area with most habitat heterogeneity (Sotavento) corresponded to greatest diversity., There was a positive relationship between Spisula solida and Chamelea gallina landings and bivalve diversity 2 years and 1 year later, respectively. Possibly, local fisheries, by selectively withdrawing the commercial numerically dominant species from the ecosystem, increased diversity 1 to 2 years later, as the ecological niches of the dominants are quickly filled by several other species thereby creating a more even community. On regional scales, no significant impact was found on long-term bivalve diversity in local fisheries., This work was part of an MMR Post-doc program financed by Fundação para a Ciência e a Tecnologia BPD /14935/ 2004.