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Ceratium furcoides is a freshwater dinoflagellate originally from cold waters of northern Europe that has been expanding its distribution into new areas worldwide. Species distribution modeling (SDM) based on maximum entropy algorithm (MaxEnt) showed that C. furcoides has a much wider potential range than its current distribution and isothermality as the key environmental variable determining its spatial pattern. The model successfully predicts areas of introduction and the climate matching approach has identified mainly tropical and some subtropical regions as most vulnerable areas at risk of introduction and establishment of C. furcoides. Furthermore, the observed shift of the climatic niche occurred between native and non-native ranges, providing, for the first time, a robust evidence that a dinoflagellate can occupy climatically distinct niche spaces following its introduction into new areas. This is probably mirroring the lack of adequate management to deal with various impacts on drainage basins, such as ongoing accelerated cultural eutrophication coupled with river impoundments and water diversion. Thus, this framework provides helpful insights on how to optimize our ability to anticipate invasions and to avoid ecosystem services losses, as well as future studies prospects on adaptive mechanisms of this pervasive invader.

This study aimed to address the Ophiothela species distribution worldwide, report invasive populations, and investigate their association with benthic organisms through an extensive review of the scientific literature. All six Ophiothela species occur between latitudes 33o S and 38o N and, together, are dispersed across 75% of the marine realms. Spread throughout more than 6700 km of the Western Atlantic Ocean coastline, O. mirabilis is the only species recorded as invasive. Higher plasticity in substrate use was detected in invaded areas than in native ones, which indicates that substrate availability does not limit the invasive potential of O. mirabilis. The colonization affinity of Ophiothela species is high for Cnidaria species, irrespective of population origin. High densities (e.g., up to 2.8 brittle stars cm−2 per gorgonian surface) and opportunistic habitat colonization pattern found for O. mirabilis invasive populations suggest fast dispersion rates along the Atlantic coast. Therefore, the expansion of this species to nearby systems is likely, and the potential to damage native host species is high.

The intermediate disturbance hypothesis (IDH) has been thoroughly investigated, but much controversy has been found for supporting its assumptions, which rely largely on the nature of the disturbance, spatial scale, and biological predictors tested. In this paper, richness of native and non-native species along a suite of Neotropical aquatic ecosystems across a broad latitudinal and geographical range was used to test the IDH predictions. An extensive literature survey was performed to compile native species richness and the occurrence of several taxonomic groups listed as non-native for twenty-four coastal rivers and bays evenly distributed into three climatic zones (tropical, transitional, and subtropical). The climatic gradient was confirmed by NMDS and PERMANOVA, but IDH predictions were only significantly supported for native and total species richness in the coastal bays. The distribution patterns of non-native marine species showed a linear instead unimodal pattern of increase with latitudinal climatic gradient, but the responses are complex and dependent of many non-exclusive factors, such as the sampling effort per ecosystem and the potential interference of other disturbance gradients that should be further addressed to unravel the role of IDH for non-native species distribution.

Disentangling multilevel sources of variation is critical for understanding of diversity patterns in high-variability environments. We investigated the scale sensitivity of short-term environmental effects on the temporal beta diversity of fishes in 3 tropical coastal lagoons in Southeastern Brazil. Environmental effects were investigated at 3 hierarchical levels (local, zone, and lagoon). An AICc-based model selection was applied to generalized linear mixed models relating abundance-based beta diversity (Bray-Curtis dissimilarity; βBC) to environmental distances and random effects for other sources of variability. Abundance gradients (βBC-GRA) contributed more for βBC at all hierarchical levels, most likely due to random changes in the abundances of numerous rare marine-origin species. The temporal and spatial marine influences favored the balanced variation in the abundance of different species (βBC-BAL), probably by allowing for marine species with different environmental tolerances and requirements. The freshwater vs. marine influences were primarily represented by short-term effects of salinity changes at the local and zone levels and tide height and accumulated rainfall at the lagoon level. Other environmental effects (e.g. pH and transparency) were representative of that balance depending on the βBC component and hierarchical level. Random effects for morphometric features (local level, width of the connections between zones; lagoon level, distance from the ocean) and climate-related factors (local and zone levels, wind intensity and accumulated rainfall; lagoon level, changing seasons) were also relevant for the relationships between environmental variability and βBC. This study evidenced major scale-related mechanisms driving the temporal beta diversity of fishes in tropical coastal lagoons.

Syntopic species with similar anatomic configuration may face strong competition for trophic resources, thus relying on developed mechanisms to ensure coexistence. The present study investigated the influence of body size on trophic interactions between juveniles of two closely related fish species at three sandy beaches in south-eastern Brazil. A total of 150 fish were sampled, where 103 were identified as Trachinotus carolinus (mean ± SE: weight = 9 g ± 1.13) and 47 as Trachinotus goodei (weight = 46.7 g ± 3.34). A significant size-difference between juvenile Trachinotus was detected by a null-model analysis (P = 0.04), with T. carolinus (TL = 79.6 mm ± 2.4) presenting a smaller body size than T. goodei (TL = 147.7 mm ± 4.2). The main prey items consumed by T. carolinus were Perna perna (IAi = 0.76) and Emerita brasiliensis (IAi = 0.18), whereas the latter was the major T. goodei dietary prey (IAi = 0.71). Both prey were correlated with larger-sized juveniles of each pompano species, whereas smaller fish shared non-preferred trophic items. Such opportunistic behaviour of smaller juveniles may account for the dietary overlap detected between the Trachinotus species (P = 0.09). Size-related dietary partitioning was observed for the largest T. goodei juveniles, which displayed only a slight overlap with T. carolinus, and between juveniles belonging to the small and medium size groups of each pompano species. Therefore, food partitioning related to pompano body size seems to be especially important for the smallest juveniles, as they present the highest vacuity (particularly T. carolinus) in the sampled beaches, suggesting that these individuals are under intra- and interspecific competitive pressure, which may affect local coexistence.

Global inland water biodiversity is under mounting stress facing future scenarios of climate change, biological invasions, pollution, diversion, damming of rivers, and increase of water abstractions. Apart from having isolated effects, all these stressors threats act synergistically and thus pose additional emerging threats to biodiversity and ecosystem services. Native to Northern Europe, the nuisance and potential toxic dinoflagellate Ceratium furcoides (Levander) Langhans 1925 is a silent invader that blooms in freshwater systems; it has one of the most rapid spread rates globally. We propose a framework to determine the worldwide most vulnerable areas for the invasion by C. furcoides shortly (2041-2060) by combining future scenarios of climate change (a proxy for invasiveness) derived from ecological niche models with future dam construction data (a proxy for invasibility). The nine models applied in four future scenarios of greenhouse gas emission from Coupled Model Intercomparison Project Phase 6 showed a general increase in areas suitable for the invasion success of C. furcoides. High susceptibility overlapped with areas densely occupied by large and medium-size dams and future dam construction projects. Considering that C. furcoides can reproduce from a single cell, produces resistant stages, and has several strategies to cope with local environmental constraints, early detection protocols, and mitigation actions are urgently needed to avoid biodiversity declines related to this invader.

(1) Although suffers from intense pollution inputs, Guanabara Bay, the most socioeconomically and environmentally important estuary in Rio de Janeiro, Brazil, is still home to a diverse fauna, including several fish and crab species consumed by humans. The bay presents high sedimentation rates and sediment contamination, further aggravated by dredging processes carried out in recent years. In this context, this study aimed to verify the effect of the dredging process on total mercury (THg) concentrations at Guanabara Bay through swimming crab assessments sampled before (2016), during (2017), and after (2018) the dredging process, and mainly, if the detected concentrations can be harmful to consumer health, (2) Methods: Swimming crab samplings were carried out at the same time and sampling points in 2016, 2017 and 2018 and the total Hg was determined using a Direct Mercury Analyzer (DMA-80, Milestone, Bergamo, Italy), (3) Results: Increased Hg concentrations were observed during the dredging process, decreasing to lower values, close to the initial concentrations, at the end of the process. Some of the investigated abiotic factors favor Hg dynamics in the aquatic environment, while others were positively altered at some of the assessed sampling areas at the end of the dredging process, (4) Conclusions: Although crab Hg levels were below maximum permissible limits for human consumption, it is important to note that these animals are significantly consumed around Guanabara Bay, which may lead to public health issues in the long term.

Sharpnose sharks Rhizoprionodon lalandii and R. porosus are frequently captured in fishing activities in Brazil and are significantly consumed by humans, especially in southeastern Brazil. Both species lack population data and suffer intense fishing pressures and habitat degradation, consequently hindering adequate management and conservation actions. In this context, this study aimed to assess mercury (Hg) contamination in R. lalandii, and R. porosus sampled off the coast of Rio de Janeiro, addressing both animal health and public health risks. Sharks were obtained from two artisanal fishing colonies in southeastern Brazil (Copacabana and Recreio dos Bandeirantes), located on the coastal zone adjacent to Guanabara Bay, one of the most important, productive, and contaminated estuaries in Brazil, and a further three artisanal fishing colonies from the Regia˜o dos Lagos area (Saquarema, Cabo Frio and Rio das Ostras). Hg concentrations in liver, muscle, and brain in R. lalandii (n ¼ 24) and R. porosus (n ¼ 20) specimens were determined by inductively coupled plasma mass spectrometry. A gravid female measuring 112 cm from Copacabana is the first record for an individual of this size for R. lalandii. No correlation between length and muscle Hg concentrations was observed, and no differences between Hg concentrations for muscle or liver were found between male and female juveniles from either Cabo Frio or Rio das Ostras. No differences in Hg loads were observed herein for both assessed species. Low Hg bioaccumulation in juveniles and nongravid female muscle tissue was noted compared to significantly higher Hg concentrations in gravid females. Hg was detected in all embryos, indicating potential maternal offloading. As Hg thresholds for sharks in particular have not yet been established, whether the Hg concentrations detected in brain pose neurotoxic risks for these animals is not known. Public health concerns concerning adult R. lalandii consumption from Copacabana, however, are significant.

This study addressed whether species composition and structure, and functional guilds of the fish assemblages associated with rocky substrates changed gradually with the marine-estuarine gradient in Guanabara Bay, following thus the predictions for the ecocline gradient. Fish were sampled quarterly with bottom gillnet sets between September 2010 and December 2011 in four locations of Guanabara Bay, with physical and chemical water variables being concurrently measured during fish surveys. PCA corroborated the marine-estuarine gradient between the mouth of the bay (more saline, transparent and oxygenated waters) and the innermost and more estuarine areas (high temperature, and low oxygen and salinity). Most fish metrics, especially richness, Shannon diversity, and functional guilds mirroring the degree of estuary dependence, supported the hypothesis that the ecocline concept still can be applied to explain fish distribution in this highly-eutrophic bay. The upper estuary was intensively used by young stages of the diadromous species targeted by local fisheries, but least used by marine migrants and stragglers. The sites situated near the central portion of the bay shared many species with the upper and lower estuary, probably functioning as ecological corridors for fish dispersal. Our findings supported that shifts in the composition and structure of fish assemblages in Guanabara Bay comply with the ecocline concept, urging special attention to that measures toward environmental rehabilitation and further long-term assessments should be carried out to preserve the role of this complex ecosystem as breeding, nursery, and feeding site.

Guanabara Bay is located within one of the most populated areas in Brazil, still harbouring a great aquatic biodiversity and supporting important commercial fisheries despite the increased levels of human disturbances. Here, individual and simultaneous effects of water temperature, pH, and salinity on reef-associated and transient fish assemblages in a transitional marine-estuarine zone of Guanabara Bay were addressed. It was predicted that composition and structure of fish assemblages will respond differently to these environmental variables, depending on the species-specific degree of association with rocky substrates. A canonical correspondence analysis applied on all 83 fish species caught revealed that fish assemblages as a whole were mainly driven by salinity and pH, but with no clear trend of species association or seasonal responses. Canonical analysis of principal coordinates revealed a group composed only by reef-associated species, which was separated from a second group of only transient species, but some species of overlapping distribution were also detected (mixed group). Reef-associated species followed mostly a salinity gradient, whereas transient species responded to salinity and temperature, and those of the mixed group were ruled by salinity and pH. Generalized additive models indicated that, except for transient species, fish richness increased with the effects of estuarine waters from inner bay. Our study is the first to highlight the importance of a transitional zone in coastal bays, which can apparently increase the potential of sharing species among marine and estuarine areas, leading thus to positive effects on local biodiversity. We also stress the role of salinity as key structuring factor of the fish assemblages in tropical coastal bays, and its potential to be used, in conjunction with pH and temperature, as a proxy of alternating influence of estuarine and oceanic waters in these systems.

In this paper, the diet and trophic structure of fish assemblages caught in two zones of the largest (∼220 km2) hypersaline coastal lagoon in South America were addressed quarterly along 2011, and the patterns were compared among seasons and to a previous study performed during typical hypersaline conditions (i.e. 1993) to assess the short- and long-term effects of desalinisation. Our results confirmed that in 2011, Araruama Lagoon experienced a strong decrease in salinity, particularly in the autumn, with the ranging values (i.e. 37–48) remaining below to the salinities (i.e. 52–67) reported for most of the 1965–2005 period, but matching those (i.e. ≤ 41 on the average) recorded during the atypical less-hypersaline conditions of 1989–1990. Fish trophic structure recorded during 2011 was composed of five guilds, in decreasing order of biomass: planktivores (31.14%), detritivores (26.24%), invertivores (25.65%), piscivores (15.09%), and omnivores (1.58%). This structure resembled more those of similar, but comparatively less hypersaline systems in Africa and Australia, than that of extreme hypersaline lagoons in Mexico or Araruama lagoon in a typically hypersaline year. Our findings indicate that increased contributions of planktivores and detritivores could be used as promising predictors of, respectively, salination and desalinisation processes and thus shifts in the ecosystem trophic state. Variations on the biomasses of piscivores and invertivores were apparently more related to short-term salinity changes among seasons and across the lagoon zones. Since the relationships between fish trophic structure and desalinisation and its associated effects were complex, long-term studies using complementary and integrative approaches, such as stable isotopes and functional traits, are recommended to confirm our findings for Araruama Lagoon and validate our hypothesis for other similar hypersaline ecosystems.

The influence of water variables and the availability of complex bottom habitats in the sublittoral zone on surf-zone fish assemblages of sandy beaches in a Brazilian eutrophic bay were assessed. In total, 64 seine hauls were carried out bimonthly between October 2012 and September 2013 in two beaches located within a marine-estuarine transitional zone in Guanabara Bay and

Despite the increased use as tool for conservation of native fish, the creation of non-fishing reserves is more recent in Neotropical impoundments and its effectiveness rather variable. Although not intentionally created for conservation purposes, areas located near dams could function as fish reserves, since fishing activity is often forbidden in these sites for security reasons. We investigated the effects of a fishing-restricted area in Lajes Reservoir, a Neotropical reservoir dominated by invasive species, notably the yellow peacock bass Cichla kelberi, subject to intensive local fisheries. Cichlid populations associated with rocky banks of similar size and complexity were compared between fishing and non-fishing sites, after accounting for spatial autocorrelation. Native cichlids were significantly less abundant in the non-fishing area, in contrast to invasive cichlids. Accordingly, there were smaller individuals of the two native species in the fishing-allowed sites, where the mean size of peacock bass was also smaller. Our results suggest that angling can sometimes provide demographical control of large invasive piscivores and hence predation refuges for native fish in highly modified ecosystems such as reservoirs, thus resulting in reconciliation ecology. Fishing prohibition can sometimes be counterproductive for the conservation of native populations, illustrating the importance of context-specific management strategies.

Large tropical rivers are increasingly affected by dam construction, which generally implies alteration of flow regimes, increased water transparency, decline of native species and proliferation of invasive alien species. The potential of native Neotropical piscivores to provide biotic resistance to alien fish invaders and its interaction with water turbidity was investigated through mesocosm experiments. Three invasive and two native fish species were offered as prey to three native piscivores of the Parana river in 1000 L tanks. After 48 h, prey survival was compared among trials with and without the piscivores and in turbid (~ more preserved systems) versus clear water (~ disturbed systems by damming) treatments. Prey survival, particularly of the invasive species, was significantly lower in turbid water in the presence of predators (~ 45.9% versus ~ 53.7% in clear water). Piscivores preyed more on smaller individuals in clear water and on larger preys in turbid water. Although vulnerability to predation was prey-specific, our results support the potential of native piscivores to provide biotic resistance against alien freshwater species. Water turbidity mediated the predator–prey interactions and our results confirm the hypothesis that decreased turbidity caused by dams’ construction can affect predation efficiency of native piscivores and increase the abundance of alien fish.

The present study aimed to assess corocoro grunt use as bioindicator of Hg contamination in coastal marine systems by testing environmental (seasons) and biological effects (sexual maturity, size and weight) on THg accumulation and assessing human health risk. Fish was captured in winter and summer seasons at Vermelha Beach, Rio de Janeiro, Southeast Brazil. Adult O. ruber showed significantly higher THg than juveniles, and THg concentrations were positively correlated to fish length and weight. Fish THg concentrations did not differ between seasons and were below the accepted limit for human consumption. Human exposure risk by fish consumption was 0.31 μg MeHg kg−1 week−1 and the hazard quotient was 0.44 (0.11–1.84). Our results confirm the applied use of O. ruber as sentinel species for Hg contamination monitoring and highlight concern for its consumption, especially for local fishermen populations that highly consume this fish and may be more susceptible to Hg adverse effects.

This study comprises the first record of a juvenile Giant Devil Ray specimen for Rio de Janeiro, Southeastern Brazil, and its metal and metalloid contents. A scientometric assessment was also performed for the Manta and Mobula genera. Only five records were found, and only As, Cd, Pb, Hg, Pt, Pd and Rh have been assessed. All studies but one concerned human consumption. A significant knowledge gap on metal and metalloid ecotoxicology for mobulid rays is noted, indicating the emergence of a new field of research that th may be applied for wildlife conservation and management in response to anthropogenic contamination. Our study is also the first to provide Al, Cr, Cu, Fe, Mn, Sr, Ti, V and Zn contents for muscle, liver, brain and kidney for a mobulid ray and one of the scarce reports concerning As, Cd, Hg and Pb in muscle, liver and kidney.

Neotropical freshwater ecosystems are experiencing a great expansion in the number of invasive species, which is especially alarming since this region harbours 30% of the world’s fish biodiversity with high levels of endemism. We aimed to evaluate the main predictors of peacock basses (Cichla spp.) abundance outside their native range, which are the Amazon and Tocantins-Araguaia river basins. We used multivariate ordination techniques and multimodel inference to analyse peacock basses abundance in twelve reservoirs of the Paraiba do Sul river basin, southeastern Brazil. Interestingly, reservoirs at higher (southernmost) latitudes, located in more populated areas, had higher water temperature and lower turbidity, due to increased water residence time, and these three variables were also positively correlated with abundance of this warm-water invasive fish. Habitat structure was less important in explaining peacock basses abundance, which was not significantly related to biotic factors (fish species richness and time since peacock basses introduction). We hypothesize that the observed effects of reservoir management on limnological features and peacock bass abundance, particularly water residence time (as a mediator of temperature and turbidity), may apply to other Neotropical basins and could influence the impact of this invader.

The Brazilian Environmental Ministry (MMA) released a report in 2016 listing 163 non-native species into Brazilian inland waters. Reservoirs are among the freshwater habitats most frequently associated with the release of non-native species. Therefore, the aim of the present study was to evaluate the occurrence and distribution of the non-native species listed by the MMA, in large Brazilian reservoirs (≥ 30 km2). Further, we have tested the hypothesis that beta diversity of non-native species within reservoirs from the same basin is lower than those among reservoirs from distinct basins. A literature search was performed for 70 Brazilian reservoirs, resulting in the records of 91 non-native species. Reservoirs from the Parana basin showed the highest number of occurrences, with 33 non-native species recorded only in the Itaipu reservoir. Beta diversity of non-native species showed higher variability among reservoirs from different basins than those within the same basin. Some basins were also distinguished by their composition of non-native species, as supported by the IndVal index. Non-native species were widespread along Brazilian reservoirs, and their distribution can be even higher than reported.

Rocky reefs are one of the most important biotopes in Guanabara Bay due to their broad distribution and high species diversity. This study aimed to describe the composition and structure of the fish assemblage associated with rocky reefs in Vermelha Beach (RJ/Brazil), an estuarine-marine transitional zone located at the entrance of Guanabara Bay. Fish were surveyed through underwater visual censuses, conducted by snorkeling divers along 10 m²-linear transects (n = 90). A total of 2.487 fishes were recorded belonging to 29 species in 18 families. Except for Atherinella brasiliensis, all other species are intimately associated with rocky reefs. The present work also stresses the importance of further studies to evaluate the role of periodic influences of estuarine and oceanic waters as structuring factors of the fish assemblages associated with rocky reefs at Vermelha Beach and similar ecosystems.

Made available in DSpace on 2018-11-26T17:16:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-15 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The Abrolhos Bank is an area of high ecological, socio-economic importance and harbour the richest and most extensive coral reefs in the South Atlantic. Here we report the discovery of shallow (12-25 m depth) reef complex with ten large biogenic structures, intermediate between the typical mushroom-shaped pinnacles of the northern Abrolhos Bank (17 degrees-18 degrees S) and the small patch reefs found on the central/southern coast of the Espirito Santo State (19 degrees-20 degrees S). The newly discovered reefs harbour a relatively rich and abundant reef community, with 73 fish and 14 benthic cnidarian species, including endangered and commercially important ones. We discuss on urgent needs of properly mapping and understanding the ecological functioning of this reef system. Information provided here is a baseline for future impact evaluations, particularly considering the recent worst environmental disaster of Brazil from a dam collapse in Doce river that affected the region. (C) 2016 Elsevier Ltd. All rights reserved. Univ Fed Espirito Santo, Dept Oceanog & Ecol, Ave Fernando Ferrari,514 Goiabeiras, Vitoria 29075910, ES, Spain Assoc Ambiental Voz Nat, Vitoria, ES, Spain Univ Fed Estado Rio de Janeiro, Programa Posgrad Ciencias Biol Biodiversidade Neo, Rio De Janeiro, RJ, Brazil Inst Meros Brasil, Curitiba, PR, Brazil Calif Acad Sci, San Francisco, CA 94118 USA Univ Estadual Paulista, Dept Morfol, Inst Biociencias, Botucatu, SP, Brazil Inst COMAR Conservacao Marinha Brasil, Joinville, SC, Brazil Univ Fed Paraiba, Ctr Ciencias Aplicadas & Educ, Rio Tinto, PB, Brazil Univ Fed Espirito Santo, Ctr Univ Norte Espirito Santo, Sao Mateus, ES, Brazil Univ Calif Santa Cruz, Ecol & Evolutionary Biol Dept, Santa Cruz, CA 95064 USA Univ Estadual Paulista, Dept Morfol, Inst Biociencias, Botucatu, SP, Brazil CNPq: GDE 202475/ 2011-5 CNPq: 54515130/2011

Fluctuating asymmetry (FA), which can be defined as random morphologic changes on bilateral symmetry plan of paired morphometric and meristic characters in response of environmental disturbances, is an alternative tool to traditional methods of environmental health assessment that has an interesting potential to appraise the state of adaptation of a population before that acute contaminations affect the whole community or ecosystem. This study aimed to assess the occurrence of FA in three morphometric and three meristic characters of the Corocoro grunt Orthopristis ruber (Cuvier, 1830), and compare the deviations in bilateral symmetry of this reef-associated and omnivorous in Guanabara Bay (Brazil), the venue for various outdoor aquatic sports during the 2016 Olympic Games. Five indexes of FA were tested over the six characters of 66 O. ruber , which were caught during the dry and wet seasons of 2011 and at three areas Guanabara Bay of different environmental characteristics. In addition to validate the existence of FA for O. ruber , our findings revealed significant deviations in the bilateral symmetry according to the FA indexes and fish characters. Together with the FA1 index, the number of gill rakers and the number of rays of the pectoral fin provided the best methodological approach to address the levels of FA in O. ruber as a response to environmental stressors in each region. The levels of FA in O. ruber was significantly lower in the Urca region (less impacted) than for individuals caught near the Paqueta Island and Rio-Niteroi Bridge sites (more degraded). Partial Redundancy Analysis also shows that the fish characters are affected in different ways by environmental stressors, but especially in response to the levels of dissolved oxygen and, secondarily, to water transparency, and that Paqueta Island is apparently less impacted than the site near the Rio-Niteroi Bridge. Our results confirm the potential of FA to be used as a tool to detect environmental effects on a reef-associated fish species in a tropical polluted bay, but further studies are necessary to validate our findings for other species and ecosystems.

This study used the hypervariable domain of the mitochondrial DNA (mtDNA) control region (CR) to assess the genetic divergence among native and invasive populations of Cichla kelberi, which is considered the first peacock cichlid introduced and established throughout Brazil and is among the most invasive populations of this genus worldwide. The maximum likelihood tree based on 53 CR sequences with strong bootstrap support revealed that C. kelberi forms a monophyletic clade, confirming that all 30 C. kelberi studied belong to this morphotype. Additionally, the haplotype analysis of the C. kelberi sequences from 11 sampling sites revealed that invasive populations are much less diverse than native ones and largely dominated by a single haplotype that prevailed in reservoirs at the Paraiba do Sul River basin. Two haplotypes were recorded exclusively in an invasive population at Porto Rico, southern Brazil, and one private haplotype was detected in two reservoirs from Paraiba do Sul (Pereira Passos and Paracambi), suggesting more than one introduction event and that native populations should be better evaluated to encompass the entire genetic diversity of native C. kelberi. The possible route and pathways of C. kelberi introduction are also briefly discussed.

Artificial reefs (ARs) have been used globally to increase fish stocks, especially for local fisheries, but few studies have addressed the seasonal changes in fish attracted to ARs over extended periods. Bottom gillnets were used twice a year (wet versus dry seasons) to investigate how the composition and structure of fishing resources change over seasons during 20 years in the oldest experimental AR complex deployed in Southeastern Brazil. In total, 74 fish species were caught, and Sciaenidae, Carangidae and Ariidae families were the most representative in both numbers and occurrence. Fish abundance, species richness and biomass varied significantly between AR and reference site (RS), with higher values being recorded in the artificial habitats. Generalized additive models and ANOVA showed a gradual transition over time for the fish assemblages associated with the reef complex, indicating an initial phase primarily dominated by estuarine species, followed by an extended period of attraction by reef-associated fish and many species of commercial interest. The season was identified as the most important factor for the development of fish assemblages in the AR complex. Fish abundance increased gradually towards the 14th year after AR deployment and became more variable thereafter, with the stabilization or a abundance decreasing for some species. Our findings reveal that AR might be locally important for commercial species such as Rhizhoprionodon porosus, Macrodon ancylondon and Isopisthus parvipinnis, and highlight the importance of structurally complex structures as a promising strategy to enhance the attraction of fishery resources. JL Lima thanks the Research Foundation of Rio de Janeiro (FAPERJ) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for the PhD scholarship and the internship abroad scholarship, respectively. This work was financed by FAPERJ (E-26/203.002/2016) and by the Brazilian Agency for Research Development - CNPq (301084/2016-5). This study was also partially financed by the CAPES (finance code 001).

Toxins synthesized by marine benthic dinoflagellates may be transferred towards higher trophic levels via cell ingestion. Okadaic acid (OA) and other compounds produced by benthic Prorocentrum species are associated with acute and lethal fish responses, but its sublethal effects are barely known. The toxicity of low and intermediate P. lima concentrations to the ringneck blenny Parablennius pilicornis was evaluated through short-term food chain transfer experiments using brine shrimps as primary grazers of toxic cells and, subsequently, as fish prey. Fish activity level, opercular beat frequency, feces biomass, condition factor, and hepatosomatic index were used as toxicity proxies. We hypothesized that sub-lethal concentrations of DSP toxins will affect fish responses, but the strength of these effects will be mediated by the initial somatic condition of exposed individuals. Increased opercular beat frequencies were recorded in fish from the treatment with the highest P. lima concentration provided to brine shrimps, contrasting with rather variable and low opercular beat frequencies from the control. Fish fed with brine shrimps exposed to low and intermediate concentrations of P. lima showed a great inter-individual variation in activity level and particularly in opercular beat frequency, wherein the initial condition factor of exposed individuals appeared to have broadly mediated these fish responses. The presence of P. lima all year round in benthic marine systems highlights a possible chronic exposure of fish to OA and fish will likely become more susceptible to predation in natural environments, facilitating, therefore, toxin transfer through marine trophic webs.

Harmful algae may differently affect their primary grazers, causing sub-lethal effects and/or leading to their death. The present study aim to compare the effects of three toxic benthic dinoflagellates on clearance and grazing rates, behavioral changes, and survival of Artemia salina. Feeding assays consisted in 1-h incubations of brine shrimps with the toxic Prorocentrum lima, Gambierdiscus excentricus and Ostreopsis cf. ovata and the non-toxic Tetraselmis sp. Brine shrimps fed unselectively on all toxic and non-toxic algal preys, without significant differences in clearance and ingestion rates. Acute toxicity assays were performed with dinoflagellate cells in two growth phases during 7-h to assess differences in cell toxicity to A. salina. Additionally, exposure to cell-free medium was performed to evaluate its effects on A. salina survival. The behavior of brine shrimps significantly changed during exposure to the toxic dinoflagellates, becoming immobile at the bottom by the end of the trials. Dinoflagellates significantly affected A. salina survival with 100% mortality after 7-h exposure to cells in exponential phase (all treatments) and to P. lima in stationary phase. Mortality rates of brine shrimps exposed to O. cf. ovata and G. excentricus in stationary phase were 91% and 75%, respectively. However, incubations of the brine shrimps with cell-free medium did not affect A. salina survivorship. Significant differences in toxic effects between cell growth phases were only found in the survival rates of A. salina exposed to G. excentricus. Acute exposure to benthic toxic dinoflagellates induced harmful effects on behavior and survival of A. salina. Negative effects related to the toxicity of benthic dinoflagellates are thus expected on their primary grazers making them more vulnerable to predation and vectors of toxins through the marine food webs.

Fish assemblages recorded from August 2010 to July 2013 in two lotic and lentic environments of the Middle Paranć River floodplain were studied in the light of flood and flow pulse variations. Three flood pulses occurred during the period of study, each with a different magnitude, duration and timing. Instead four flow pulses were recorded during this period. The varied hydrological conditions had an influence on the ichthyofauna. The fish species richness in both lentic and lotic habitat was negatively correlated with the maximum water level and fish assemblages were spatially and temporally structured according to their different reproductive strategies. Long- and short-distance migratory species were dominant after the flood pulse of the highest intensity and longest duration, whereas sedentary fish and internal fertilisation prevailed during flow pulses and lower flood pulses. Fish assemblage similarity was generally low between habitats during flood and flow pulses, but increased after those events depending on their magnitude, duration and timing. Apparently, flow pulses would also function like floods, as mechanisms of spatio-temporal structuring of fish assemblages. Journal compilation. Fil: Espínola, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Rabuffetti, Ana Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Abrial, Elie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Amsler, Mario Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Paira, Aldo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Simões, Nadson Ressyé. Universidade Federal Do Sul Da Bahia; Brasil Fil: Santos Das Neves, Luciano. Universidade Federal Do Estado Do Rio de Janeiro; Brasil