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1.
J Acoust Soc Am ; 149(1): 652, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514174

RESUMO

Confinement due to the COVID-19 pandemic drastically reduced human activities. Underwater soundscape variations are discussed in this study, comparing a typical and confinement day in a coastal lagoon near a popular tourist city in Mexico. Recording devices were located at 2 m in depth and 430 m away from the main promenade-a two-way avenue for light vehicle traffic-where main tourist infrastructure is located. The nearby marine environment is habitat to birds and dolphins as well as fish and invertebrates of commercial importance. Medium and small boats usually transit the area. The main underwater sound level reduction was measured at low frequencies (10-2000 Hz) because of the decrease in roadway noise. Vessel traffic also decreased by almost three quarters, although the level reduction due to this source was less noticeable. As typical day levels in the roadway noise band can potentially mask fish sounds and affect other low frequency noise-sensitive marine taxa, this study suggests that comprehensive noise analysis in coastal marine environments should consider the contribution from nearby land sources.


Assuntos
/epidemiologia , Monitoramento Ambiental/métodos , Veículos Automotores , Ruído/efeitos adversos , Quarentena/tendências , Animais , Peixes/fisiologia , Humanos , México/epidemiologia , Oceanos e Mares/epidemiologia , Espectrografia do Som/métodos , Espectrografia do Som/tendências
2.
Ecotoxicol Environ Saf ; 208: 111655, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396169

RESUMO

An enormous amount of oil-containing drill cuttings have been produced by the marine oil and gas industry. The environmental impacts of discharged drilling waste have been extensively studied. However, there is still an urgent need to develop alternative methods to identify the genotoxicity of untreated and treated drill waste in a timely manner before it is discharged. In this study, we developed a relatively rapid, sensitive, and accurate genotoxicity-detection method using Comet assay and the marine benthic goby Mugilogobius chulae. This goby is sensitive to a standard toxicant mitomycin C (MMC). The optimal exposure period for genotoxicity detection using M. chulae was determined. Three genotoxic indices (tail length (TL), tail DNA content (TD), and tail moment (TM)) were used to assess the effectiveness of high-temperature treatment of oil-contaminated waste. Untreated oil-containing drill cuttings exhibited the highest genotoxicity to goby cells. Genotoxicity was dramatically reduced after thermal treatment of drill cuttings at 350 °C and 500 °C. TD and TM exhibited significant correlation with the concentration of total petroleum hydrocarbons (TPHs)/total polycyclic aromatic hydrocarbons (PAHs) according to Pearson and Mantel correlation analyses (P values were <0.05). Using redundancy analysis (RDA) and variation partition analysis (VPA), the genotoxic effects of the drill cuttings were ascribed to total alkanes and specific groups of PAHs. In conclusion, this newly established biological model has the potential to be widely used to detect the genetic damage of untreated or treated oil-containing drill cuttings discharged into the marine environment.


Assuntos
Dano ao DNA , Monitoramento Ambiental/métodos , Peixes/genética , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ensaio Cometa , Peixes/fisiologia , Temperatura Alta , Hidrocarbonetos/análise , Hidrocarbonetos/toxicidade , Campos de Petróleo e Gás/química , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Eliminação de Resíduos , Poluentes Químicos da Água/análise
3.
Ecotoxicol Environ Saf ; 209: 111821, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360593

RESUMO

To evaluate the effects on biochemicals, antioxidants, immune responses and disease resistance of the snakehead fish, following exposure to deltamethrin at 0.061, 0.121, 0.242, 0.485 and 0.970 µg/L. After 28 d, the biochemical, the levels of antioxidant enzymes and immune enzymes in liver, spleen, kidney and intestine were negatively related to the concentrations of deltamethrin exposure. Likewise, the survival rates of the fish after 7 d challenge with Aeromonas veronii were negatively related. The levels of IL-1ß, IL-8, TNF-α, Hsp70 and malondialdehyde in liver, spleen, kidney and intestine were positively connected to the concentrations of deltamethrin exposure. Results demonstrated that environmentally relevant concentrations (0.121, 0.242, 0.485 and 0.970 µg/L) inhibited the biochemicals, antioxidants and immune responses and disease resistance of snakehead fish.


Assuntos
Peixes/fisiologia , Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Antioxidantes/metabolismo , Peixes/imunologia , Imunidade , Rim , Fígado/efeitos dos fármacos , Malondialdeído/metabolismo , Baço/efeitos dos fármacos
4.
PLoS One ; 15(12): e0243273, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33320906

RESUMO

Antifreeze proteins inhibit ice growth and are crucial for the survival of supercooled fish living in icy seawater. Of the four antifreeze protein types found in fishes, the globular type III from eelpouts is the one restricted to a single infraorder (Zoarcales), which is the only clade know to have antifreeze protein-producing species at both poles. Our analysis of over 60 unique antifreeze protein gene sequences from several Zoarcales species indicates this gene family arose around 18 Ma ago, in the Northern Hemisphere, supporting recent data suggesting that the Arctic Seas were ice-laden earlier than originally thought. The Antarctic was subject to widespread glaciation over 30 Ma and the Notothenioid fishes that produce an unrelated antifreeze glycoprotein extensively exploited the adjoining seas. We show that species from one Zoarcales family only encroached on this niche in the last few Ma, entering an environment already dominated by ice-resistant fishes, long after the onset of glaciation. As eelpouts are one of the dominant benthic fish groups of the deep ocean, they likely migrated from the north to Antarctica via the cold depths, losing all but the fully active isoform gene along the way. In contrast, northern species have retained both the fully active (QAE) and partially active (SP) isoforms for at least 15 Ma, which suggests that the combination of isoforms is functionally advantageous.


Assuntos
Migração Animal , Proteínas Anticongelantes/genética , Mudança Climática , Proteínas de Peixes/genética , Perciformes/genética , Sequência de Aminoácidos , Animais , Regiões Antárticas , Proteínas Anticongelantes/análise , Proteínas Anticongelantes Tipo III/análise , Proteínas Anticongelantes Tipo III/genética , Regiões Árticas , Proteínas de Peixes/análise , Peixes/genética , Peixes/fisiologia , Oceanos e Mares , Perciformes/fisiologia , Filogenia , Alinhamento de Sequência
5.
Artigo em Inglês | MEDLINE | ID: mdl-33352927

RESUMO

The objectives of the present study were to determine the concentrations of heavy metals and metalloids in water, sediment and Osteochilus vittatus fish, and to assess chromosome aberrations, serum biochemical changes and histopathological alterations in O. vittatus from the Nam Kok river near the Sepon gold-copper mine, Lao People's Democratic Republic compared with the reference area. The results showed that Fe, Mn and Ni in water, As and Cd in sediment as well as As, Cd, Cr, Mn and Ni in O. vittatus muscle samples near the gold-copper mine exceeded standard values. Furthermore, the chromosome assessment in O. vittatus revealed seven types of chromosome aberrations, and the highest total number of chromosome aberrations was a centromere gap. The total number of chromosome aberrations, cell number with chromosome aberrations and percentage of chromosome aberrations in O. vittatus as well as serum liver enzymes between the studied areas were significantly different (p < 0.05). The liver histopathological alterations of the fish near the gold-copper mine revealed atypical cellular structures as nuclear membrane degeneration, rough endoplasmic reticulum disintegration and abnormal cytoplasmic mitochondria. The results of this study suggested that heavy metal and metalloid contaminations from the Sepon gold-copper mine area negatively affect O. vittatus fish in terms of chromosomal defects, serum biochemical changes and liver histopathological appearances.


Assuntos
Cromossomos/efeitos dos fármacos , Peixes/fisiologia , Metaloides/toxicidade , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cromossomos/química , Cobre/toxicidade , Monitoramento Ambiental , Ouro , Humanos , Laos , Metaloides/análise , Metais Pesados/análise , Mineração , Poluentes Químicos da Água/análise
6.
Proc Natl Acad Sci U S A ; 117(52): 33396-33403, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33328271

RESUMO

Repeatable, convergent outcomes are prima facie evidence for determinism in evolutionary processes. Among fishes, well-known examples include microevolutionary habitat transitions into the water column, where freshwater populations (e.g., sticklebacks, cichlids, and whitefishes) recurrently diverge toward slender-bodied pelagic forms and deep-bodied benthic forms. However, the consequences of such processes at deeper macroevolutionary scales in the marine environment are less clear. We applied a phylogenomics-based integrative, comparative approach to test hypotheses about the scope and strength of convergence in a marine fish clade with a worldwide distribution (snappers and fusiliers, family Lutjanidae) featuring multiple water-column transitions over the past 45 million years. We collected genome-wide exon data for 110 (∼80%) species in the group and aggregated data layers for body shape, habitat occupancy, geographic distribution, and paleontological and geological information. We also implemented approaches using genomic subsets to account for phylogenetic uncertainty in comparative analyses. Our results show independent incursions into the water column by ancestral benthic lineages in all major oceanic basins. These evolutionary transitions are persistently associated with convergent phenotypes, where deep-bodied benthic forms with truncate caudal fins repeatedly evolve into slender midwater species with furcate caudal fins. Lineage diversification and transition dynamics vary asymmetrically between habitats, with benthic lineages diversifying faster and colonizing midwater habitats more often than the reverse. Convergent ecological and functional phenotypes along the benthic-pelagic axis are pervasive among different lineages and across vastly different evolutionary scales, achieving predictable high-fitness solutions for similar environmental challenges, ultimately demonstrating strong determinism in fish body-shape evolution.


Assuntos
Organismos Aquáticos/fisiologia , Evolução Biológica , Peixes/fisiologia , Água , Animais , Ecossistema , Modelos Teóricos , Filogenia , Filogeografia , Incerteza
7.
Nat Commun ; 11(1): 5408, 2020 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-33106484

RESUMO

It has long been proposed that flying and swimming animals could exploit neighbour-induced flows. Despite this it is still not clear whether, and if so how, schooling fish coordinate their movement to benefit from the vortices shed by others. To address this we developed bio-mimetic fish-like robots which allow us to measure directly the energy consumption associated with swimming together in pairs (the most common natural configuration in schooling fish). We find that followers, in any relative position to a near-neighbour, could obtain hydrodynamic benefits if they exhibit a tailbeat phase difference that varies linearly with front-back distance, a strategy we term 'vortex phase matching'. Experiments with pairs of freely-swimming fish reveal that followers exhibit this strategy, and that doing so requires neither a functioning visual nor lateral line system. Our results are consistent with the hypothesis that fish typically, but not exclusively, use vortex phase matching to save energy.


Assuntos
Peixes/fisiologia , Animais , Fenômenos Biomecânicos , Biomimética , Hidrodinâmica , Sistema da Linha Lateral/química , Sistema da Linha Lateral/fisiologia , Robótica , Natação
8.
PLoS One ; 15(10): e0239895, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002046

RESUMO

Knowledge of continental shelf faunal biodiversity of Antarctica is patchy and as such, the ecology of this unique ecosystem is not fully understood. To this end, we deployed baited cameras at 20 locations along ~ 500 km of the Western Antarctic Peninsula (WAP) at depths from 90 to 797 m. We identified 111 unique taxa, with mud bottom accounting for 90% of the dominant (≥ 50% cover) habitat sampled. Amphipoda comprised 41% of the total maximum number of individuals per camera deployment (MaxN) and occurred on 75% of deployments. Excluding this taxon, the highest MaxN occurred around King George/25 de Mayo Island and was driven primarily by the abundance of krill (Euphausiidae), which accounted for 36% of total average MaxN among deployments around this island. In comparison, krill comprised 22% of total average MaxN at Deception Island and only 10% along the peninsula. Taxa richness, diversity, and evenness all increased with depth and depth explained 18.2% of the variation in community structure among locations, which may be explained by decreasing ice scour with depth. We identified a number of Vulnerable Marine Ecosystem taxa, including habitat-forming species of cold-water corals and sponge fields. Channichthyidae was the most common fish family, occurring on 80% of all deployments. The Antarctic jonasfish (Notolepis coatsorum) was the most frequently encountered fish taxa, occurring on 70% of all deployments and comprising 25% of total MaxN among all deployments. Nototheniidae was the most numerically abundant fish family, accounting for 36% of total MaxN and was present on 70% of the deployments. The WAP is among the fastest warming regions on Earth and mitigating the impacts of warming, along with more direct impacts such as those from fishing, is critical in providing opportunities for species to adapt to environmental change and to preserve this unique ecosystem.


Assuntos
Biodiversidade , Ambientes Extremos , Animais , Regiões Antárticas , Antozoários/fisiologia , Peixes/fisiologia , Poríferos/fisiologia , Água do Mar
9.
PLoS One ; 15(9): e0237374, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877404

RESUMO

Large predators play important ecological roles, yet many are disproportionately imperiled. In marine systems, artificial reefs are often deployed to restore degraded reefs or supplement existing reefs, but it remains unknown whether these interventions benefit large predators. Comparative field surveys of thirty artificial and natural reefs across ~200 km of the North Carolina, USA coast revealed large reef-associated predators were more dense on artificial than natural reefs. This pattern was associated with higher densities of transient predators (e.g. jacks, mackerel, barracuda, sharks) on artificial reefs, but not of resident predators (e.g., grouper, snapper). Further analyses revealed that this pattern of higher transient predator densities on artificial reefs related to reef morphology, as artificial reefs composed of ships hosted higher transient predator densities than concrete reefs. The strength of the positive association between artificial reefs and transient predators increased with a fundamental habitat trait-vertical extent. Taller artificial reefs had higher densities of transient predators, even when accounting for habitat area. A global literature review of high trophic level fishes on artificial and natural habitats suggests that the overall pattern of more predators on artificial habitats is generalizable. Together, these findings provide evidence that artificial habitats, especially those like sunken ships that provide high vertical structure, may support large predators.


Assuntos
Recifes de Corais , Comportamento Predatório/fisiologia , Animais , Peixes/fisiologia , Geografia , Estados Unidos
10.
Proc Biol Sci ; 287(1935): 20201752, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32993472

RESUMO

Group living is a common strategy used by fishes to improve their fitness. While sociality is associated with many benefits in natural environments, including predator avoidance, this behaviour may be maladaptive in the Anthropocene. Humans have become the dominant predator in many marine systems, with modern fishing gear developed to specifically target groups of schooling species. Therefore, ironically, behavioural strategies which evolved to avoid non-human predators may now actually make certain fish more vulnerable to predation by humans. Here, we use an individual-based model to explore the evolution of fish schooling behaviour in a range of environments, including natural and human-dominated predation conditions. In our model, individual fish may leave or join groups depending on their group-size preferences, but their experienced group size is also a function of the preferences of others in the population. Our model predicts that industrial fishing selects against individual-level behaviours that produce large groups. However, the relationship between fishing pressure and sociality is nonlinear, and we observe discontinuities and hysteresis as fishing pressure is increased or decreased. Our results suggest that industrial fishing practices could be altering fishes' tendency to school, and that social behaviour should be added to the list of traits subject to fishery-induced evolution.


Assuntos
Pesqueiros , Peixes/fisiologia , Comportamento Social , Animais , Conservação dos Recursos Naturais , Seleção Genética
11.
Proc Natl Acad Sci U S A ; 117(41): 25580-25589, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32989156

RESUMO

Anthropogenic environmental change is altering the behavior of animals in ecosystems around the world. Although behavior typically occurs on much faster timescales than demography, it can nevertheless influence demographic processes. Here, we use detailed data on behavior and empirical estimates of demography from a coral reef ecosystem to develop a coupled behavioral-demographic ecosystem model. Analysis of the model reveals that behavior and demography feed back on one another to determine how the ecosystem responds to anthropogenic forcing. In particular, an empirically observed feedback between the density and foraging behavior of herbivorous fish leads to alternative stable ecosystem states of coral population persistence or collapse (and complete algal dominance). This feedback makes the ecosystem more prone to coral collapse under fishing pressure but also more prone to recovery as fishing is reduced. Moreover, because of the behavioral feedback, the response of the ecosystem to changes in fishing pressure depends not only on the magnitude of changes in fishing but also on the pace at which changes are imposed. For example, quickly increasing fishing to a given level can collapse an ecosystem that would persist under more gradual change. Our results reveal conditions under which the pace and not just the magnitude of external forcing can dictate the response of ecosystems to environmental change. More generally, our multiscale behavioral-demographic framework demonstrates how high-resolution behavioral data can be incorporated into ecological models to better understand how ecosystems will respond to perturbations.


Assuntos
Mudança Climática , Ecossistema , Retroalimentação Fisiológica/fisiologia , Modelos Biológicos , Animais , Antozoários/fisiologia , Recifes de Corais , Peixes/fisiologia , Herbivoria/fisiologia , Atividades Humanas , Humanos
12.
PLoS One ; 15(9): e0228974, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32976488

RESUMO

Parental care elevates reproductive success by allocating resources into the upbringing of the offspring. However, it also imposes strong costs for the care-giving parent and can foster sexual dimorphism. Trade-offs between the reproductive system and the immune system may result in differential immunological capacities between the care-providing and the non-care-providing parent. Usually, providing care is restricted to the female sex making it impossible to study a sex-independent influence of parental investment on sexual immune dimorphism. The decoupling of sex-dependent parental investment and their influences on the parental immunological capacity, however, is possible in syngnathids, which evolved the unique male pregnancy on a gradient ranging from a simple carrying of eggs on the trunk (Nerophinae, low paternal investment) to full internal pregnancy (Syngnathus, high paternal investment). In this study, we compared candidate gene expression between females and males of different gravity stages in three species of syngnathids (Syngnathus typhle, Syngnathus rostellatus and Nerophis ophidion) with different male pregnancy intensities to determine how parental investment influences sexual immune dimorphism. While our data failed to detect sexual immune dimorphism in the subset of candidate genes assessed, we show a parental care specific resource-allocation trade-off between investment into pregnancy and immune defense when parental care is provided.


Assuntos
Peixes/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Sistema Imunitário/fisiologia , Caracteres Sexuais , Processos de Determinação Sexual/imunologia , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Poder Familiar , Processos de Determinação Sexual/genética
13.
PLoS One ; 15(9): e0238550, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32976502

RESUMO

Knowledge of community resilience aids the development of strategies to mitigate the impacts of a disturbance. An extreme low-seawater temperature event in late January and February 2008 resulted in high fish mortality in the coastal waters of the Penghu Islands, Taiwan. In this study, we used underwater diving visual censuses to analyze fish communities at eight sampling stations along the coast of the Penghu Islands for seven years after the 2008 event. We evaluated community metrics, including species richness, abundance-weighted diversity, average thermal affinity, and average trophic level, and described the temporal variation in select dominant species abundances. Species richness and diversity of the communities required 53 months to reach a steady-state at the sampling stations following the cold water intrusion. The cold event initially reduced community thermal affinity, which then increased throughout the study period, reflecting the recovery of the community to baseline thermal conditions. The increased average trophic level after the cold event implied that the temperature shock decreased the proportion of lower trophic-level fishes. Average trophic level declined as the communities recovered from the disturbance, reflecting the recovery of the community to baseline species composition in terms of feeding habit. Our results suggest that functional diversity may require longer to recover than taxonomic diversity for communities in the Penghu Islands.


Assuntos
Biodiversidade , Peixes , Animais , Clima , Temperatura Baixa , Ecossistema , Peixes/fisiologia , Água do Mar/análise , Taiwan
14.
Proc Biol Sci ; 287(1935): 20192939, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32933441

RESUMO

Salamanders, frog tadpoles and diverse lizards have the remarkable ability to regenerate tails. Palaeontological data suggest that this capacity is plesiomorphic, yet when the developmental and genetic architecture of tail regeneration arose is poorly understood. Here, we show morphological and molecular hallmarks of tetrapod tail regeneration in the West African lungfish Protopterus annectens, a living representative of the sister group of tetrapods. As in salamanders, lungfish tail regeneration occurs via the formation of a proliferative blastema and restores original structures, including muscle, skeleton and spinal cord. In contrast with lizards and similar to salamanders and frogs, lungfish regenerate spinal cord neurons and reconstitute dorsoventral patterning of the tail. Similar to salamander and frog tadpoles, Shh is required for lungfish tail regeneration. Through RNA-seq analysis of uninjured and regenerating tail blastema, we show that the genetic programme deployed during lungfish tail regeneration maintains extensive overlap with that of tetrapods, with the upregulation of genes and signalling pathways previously implicated in amphibian and lizard tail regeneration. Furthermore, the lungfish tail blastema showed marked upregulation of genes encoding post-transcriptional RNA processing components and transposon-derived genes. Our results show that the developmental processes and genetic programme of tetrapod tail regeneration were present at least near the base of the sarcopterygian clade and establish the lungfish as a valuable research system for regenerative biology.


Assuntos
Peixes/fisiologia , Cauda/fisiologia , Animais , Extremidades/fisiologia , Filogenia , Regeneração/fisiologia
15.
Proc Biol Sci ; 287(1935): 20201456, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32933449

RESUMO

To be effective, animal colour signals must attract attention-and therefore need to be conspicuous. To understand the signal function, it is useful to evaluate their conspicuousness to relevant viewers under various environmental conditions, including when visual scenes are cluttered by objects of varying colour. A widely used metric of colour difference (ΔS) is based on the receptor noise limited (RNL) model, which was originally proposed to determine when two similar colours appear different from one another, termed the discrimination threshold (or just noticeable difference). Estimates of the perceptual distances between colours that exceed this threshold-termed 'suprathreshold' colour differences-often assume that a colour's conspicuousness scales linearly with colour distance, and that this scale is independent of the direction in colour space. Currently, there is little behavioural evidence to support these assumptions. This study evaluated the relationship between ΔS and conspicuousness in suprathreshold colours using an Ishihara-style test with a coral reef fish, Rhinecanthus aculeatus. As our measure of conspicuousness, we tested whether fish, when presented with two colourful targets, preferred to peck at the one with a greater ΔS - from the average distractor colour. We found the relationship between ΔS and conspicuousness followed-- a sigmoidal function, with high ΔS colours perceived as equally conspicuous. We found that the relationship between ΔS and conspicuousness varied across colour space (i.e. for different hues). The sigmoidal detectability curve was little affected by colour variation in the background or when colour distance was calculated using a model that does not incorporate receptor noise. These results suggest that the RNL model may provide accurate estimates for perceptual distance for small suprathreshold distance colours, even in complex viewing environments, but must be used with caution with perceptual distances exceeding- -10 ΔS.


Assuntos
Escamas de Animais/fisiologia , Peixes/fisiologia , Animais , Percepção de Cores , Recifes de Corais , Pigmentação , Tetraodontiformes/fisiologia
16.
Nat Commun ; 11(1): 3832, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737315

RESUMO

Tropical ectotherms are hypothesized to be vulnerable to environmental changes, but cascading effects of organismal tolerances on the assembly and functioning of reef fish communities are largely unknown. Here, we examine differences in organismal traits, assemblage structure, and productivity of cryptobenthic reef fishes between the world's hottest, most extreme coral reefs in the southern Arabian Gulf and the nearby, but more environmentally benign, Gulf of Oman. We show that assemblages in the Arabian Gulf are half as diverse and less than 25% as abundant as in the Gulf of Oman, despite comparable benthic composition and live coral cover. This pattern appears to be driven by energetic deficiencies caused by responses to environmental extremes and distinct prey resource availability rather than absolute thermal tolerances. As a consequence, production, transfer, and replenishment of biomass through cryptobenthic fish assemblages is greatly reduced on Earth's hottest coral reefs. Extreme environmental conditions, as predicted for the end of the 21st century, could thus disrupt the community structure and productivity of a critical functional group, independent of live coral loss.


Assuntos
Antozoários/fisiologia , Biodiversidade , Peixes/fisiologia , Modelos Estatísticos , Adaptação Fisiológica , Animais , Biomassa , Recifes de Corais , Planeta Terra , Ecossistema , Peixes/classificação , Cadeia Alimentar , Temperatura Alta , Oriente Médio , Oceanos e Mares
17.
Chemosphere ; 261: 127714, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32738711

RESUMO

Lead (Pb) is a harmful metal element for aquatic animals. The aim of this study was to determine waterborne Pb exposure on oxidative stress, serum biochemistry and heat shock proteins (HSPs) genes expression in Channa argus. Fish were randomly divided into four groups and the Pb concentrations were 0, 50, 200, and 800 µg/L, respectively. The results showed that the accumulation of Pb was detected in the gill, intestine, liver and muscle following exposure to Pb. Pb accumulation content in tissues was gill > intestinal > liver > muscle. With the increased of Pb exposure concentrations, the levels of catalase (CAT), glutathione peroxidase (GPx), lysozyme (LZM) and immunoglobulin M (IgM) significantly decreased. Serum biochemistry, oxidative stress parameters and HSPs gene expression were all enhanced with the increase following Pb expose concentration. Our results suggest that waterborne Pb exposure can induce Pb accumulation, oxidative stress and immune response in C. argus.


Assuntos
Peixes/fisiologia , Chumbo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Bioacumulação , Catalase/metabolismo , Peixes/metabolismo , Expressão Gênica , Brânquias/metabolismo , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico/metabolismo , Chumbo/metabolismo , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/metabolismo
18.
Proc Biol Sci ; 287(1932): 20201459, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32752983

RESUMO

Hybridization events are not uncommon in marine environments where physical barriers are attenuated. Studies of coral reef taxa have suggested that hybridization predominantly occurs between parapatric species distributed along biogeographic suture zones. By contrast, little is known about the extent of sympatric hybridization on coral reefs, despite the large amount of biogeographic overlap shared by many coral reef species. Here, we investigate if the propensity for hybridization along suture zones represents a general phenomenon among coral reef fishes, by focusing on the marine angelfishes (family Pomacanthidae). Although hybridization has been reported for this family, it has not been thoroughly surveyed, with more recent hybridization studies focusing instead on closely related species from a population genetics perspective. We provide a comprehensive survey of hybridization among the Pomacanthidae, characterize the upper limits of genetic divergences between hybridizing species and investigate the occurrence of sympatric hybridization within this group. We report the occurrence of hybridization involving 42 species (48% of the family) from all but one genus of the Pomacanthidae. Our results indicate that the marine angelfishes are among the groups of coral reef fishes with the highest incidences of hybridization, not only between sympatric species, but also between deeply divergent lineages.


Assuntos
Peixes/fisiologia , Hibridização Genética , Simpatria , Animais , Recifes de Corais , Fluxo Gênico , Genética Populacional
19.
PLoS One ; 15(8): e0236200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32846430

RESUMO

Indo-Pacific lionfish have become invasive throughout the western Atlantic. Their predatory effects have been the focus of much research and are suggested to cause declines in native fish abundance and diversity across the invaded range. However, little is known about their non-consumptive effects, or their effects on invertebrates. Lionfish use shelters on the reef, thus there is potential for competition with other shelter-dwelling organisms. We demonstrate similar habitat associations between invasive lionfish, native spiny lobsters (Panulirus argus) and native long-spined sea urchins (Diadema antillarum), indicating the potential for competition. We then used a laboratory experiment to compare activity and shelter use of each species when alone and when lionfish were paired with each native species. Spiny lobsters increased their activity but did not change their shelter use in the presence of a lionfish, whilst long-spined sea urchins changed neither their activity nor shelter use. However, lionfish reduced their shelter use in the presence of spiny lobsters and long-spined sea urchins. This study highlights the importance not only of testing for the non-consumptive effects of invasive species, but also exploring whether native species exert non-consumptive effects on the invasive.


Assuntos
Peixes/fisiologia , Comportamento de Retorno ao Território Vital , Espécies Introduzidas , Palinuridae/fisiologia , Ouriços-do-Mar/fisiologia , Distribuição Animal , Animais , Região do Caribe , Recifes de Corais , Dinâmica Populacional
20.
PLoS One ; 15(8): e0237996, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822408

RESUMO

Identifying juvenile habitats is critical for understanding a species' ecology and for focusing spatial fishery management by defining references like essential fish habitat (EFH). Here, we used vector autoregressive spatio-temporal models (VAST) to delineate spatial and temporal patterns in juvenile density for 13 commercially important species of groundfishes off the US west coast. In particular, we identified hotspots with high juvenile density. Three qualitative patterns of distribution and abundance emerged. First, Dover sole Microstomus pacificus, Pacific grenadier Coryphaenoides acrolepis, shortspine thornyhead Sebastolobus alascanus, and splitnose rockfish Sebastes diploproa had distinct, spatially-limited hotspots that were spatially consistent through time. Next, Pacific hake Merluccius productus and darkblotched rockfish Sebastes crameri had distinct, spatially limited hotspots, but the location of these hotspots varied through time. Finally, arrowtooth flounder Atheresthes stomias, English sole Parophrys vetulus, sablefish Anoplopoma fimbria, Pacific grenadier Coryphaenoides acrolepis, lingcod Ophiodon elongatus, longspine thornyhead Sebastolobus altivelis, petrale sole Eopsetta jordani, and Pacific sanddab Citharichthys sordidus had large hotspots that spanned a broad latitudinal range. These habitats represent potential, if not likely, nursery areas, the location of which will inform spatial management.


Assuntos
Ecossistema , Peixes/fisiologia , Animais , California , Peixes/crescimento & desenvolvimento , Linguado/fisiologia , Gadiformes/fisiologia , Perciformes/fisiologia
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