Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.173
Filtrar
1.
PLoS One ; 15(3): e0230485, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210459

RESUMO

Globally, groupers (Epinephelidae) that form fish spawning aggregations (FSAs) are highly vulnerable to overfishing and often require site-specific approaches to management. Over 5-years (2009-2013), we conducted underwater visual censuses (UVC) at a well-known spawning site at Njari Island, Gizo, Western Province, Solomon Islands, that supports aggregations of squaretail coralgrouper (Plectropomus areolatus), camouflage grouper (Epinephelus polyphekadion) and brown-marbled grouper (E. fuscoguttatus). Findings show that while there were species-specific variations in the duration and timing of the spawning season, aggregation densities peaked from March to June, representing the main spawning season for all three species. For P. areolatus, gonad analysis from samples taken from 2008 to 2011 confirmed reproductive activity in support of density trends observed through UVC. Over the 5-year UVC monitoring period, FSA densities declined for P. areolatus and E. polyphekadion. Conversely, following the first year of monitoring, E. fuscoguttatus densities increased. These inter-specific differences may reflect variable responses to fishing as shown elsewhere, or for example, differences in recruitment success. In response to known declines in FSAs of these species, in 2018 the Solomon Islands government placed a nationwide ban on these species' harvest and sale between October and January. As this study shows, this ban does not encompass the peak aggregation period at Njari and will offer limited protection to other FSAs of these species that are known to vary in reproductive seasonality across the Solomon Islands. A more biologically meaningful and practical management strategy would be to implement a nationwide ban on the harvest and sale of these groupers each month between full and new moons when these FSAs form consistently throughout the country. Since effective management of FSAs typically requires a combined approach, spatial management that protects both spawning sites and reproductive migratory corridors is warranted.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Perciformes/fisiologia , Reprodução/fisiologia , Animais , Feminino , Masculino , Melanesia
2.
Environ Pollut ; 261: 114194, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32113106

RESUMO

As in the rest of the world, plastics are the most dominant marine litter category in Moroccan Atlantic waters. This work aims to identify the presence of microplastics in the stomach contents of three small pelagic species of the Central zone of the Atlantic, located between Cape Cantin (33°N) and Cape Boujdor (26°N): Scomber spp., Truchurus truchurus and Sardina pilchardus; Also, to map the spatial distribution of the investigated species. A total of 251 individuals were examined, composed by 118 Scomber spp, 82 Sardina pilchardus and 51 Trachurus trachurus. The characterization of microplastics ingested by those species was identified by FTIR. The results showed the presence of three polymers: Polyamide (PA), Acrylic (PC) and Polystyrene (PS), in 26% of the individuals studied. The presence of polymers was accumulated in Atlantic horse mackerel (Truchurus truchurus) with 30%, then in mackerels (Scomber spp.) with 27%, and European pilchardus (Sardina pilchardus) (9%). Fish containing microplastics in their stomachs are concentrated, mainly in the northern part of the study area. This zone has significant artisanal fishing activity and large rivers that can be source of microplastics.


Assuntos
Ingestão de Alimentos , Monitoramento Ambiental , Microplásticos , Perciformes , Animais , Oceano Atlântico , Conteúdo Gastrointestinal , Microplásticos/análise , Microplásticos/metabolismo , Marrocos , Perciformes/fisiologia , Poluentes Químicos da Água/análise
3.
Nat Commun ; 11(1): 1159, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127522

RESUMO

Social learning is often proposed as an important driver of the evolution of human cooperation. In this view, cooperation in other species might be restricted because it mostly relies on individually learned or innate behaviours. Here, we show that juvenile cleaner fish (Labroides dimidiatus) can learn socially about cheating consequences in an experimental paradigm that mimics cleaners' cooperative interactions with client fish. Juvenile cleaners that had observed adults interacting with model clients learned to (1) behave more cooperatively after observing clients fleeing in response to cheating; (2) prefer clients that were tolerant to cheating; but (3) did not copy adults' arbitrary feeding preferences. These results confirm that social learning can play an active role in the development of cooperative strategies in a non-human animal. They further show that negative responses to cheating can potentially shape the reputation of cheated individuals, influencing cooperation dynamics in interaction networks.


Assuntos
Comportamento Animal , Perciformes/fisiologia , Comportamento Social , Fatores Etários , Animais , Comportamento Alimentar/fisiologia
4.
J Fish Biol ; 96(3): 782-794, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32017088

RESUMO

The construction of dams and weirs, and associated changes to hydrological and hydraulic (e.g., water level and velocity) characteristics of rivers is a key environmental threat for fish. These multiple stressors potentially can affect fish in a variety of ways, including by causing changes in their movement, habitat use and activity. Understanding how and why these changes occur can inform management efforts to ameliorate these threats. In this context, we used acoustic telemetry to examine habitat use, longitudinal movement and activity of two lowland river fishes, Murray cod Maccullochella peelii and golden perch Macquaria ambigua, in a weir pool environment in south-eastern Australia. We compared our results to published studies on riverine populations to determine if their behaviours are similar (or not). We show that M. peelii and M. ambigua in a weir pool exhibited some similar behaviours to conspecific riverine populations, such as strong site fidelity and use of woody habitat for M. ambigua. However, some behaviours, such as large-scale (tens-hundreds of kilometres) movements documented for riverine populations, were rarely observed. These differences potentially reflect flow regulation (e.g., stable water levels, loss of hydraulic cues) in the weir pool. The two species also exhibited contrasting responses to dissolved oxygen conditions in the weir pool, which may reflect differences in their life history. Overall, this study shows that although some aspects of these two native fishes' life history can continue despite flow regulation, other aspects may change in weir pools, potentially impacting on long-term population persistence.


Assuntos
Ecossistema , Perciformes/fisiologia , Rios , Migração Animal , Animais , Oxigênio/metabolismo , Austrália do Sul
5.
J Fish Biol ; 96(3): 806-814, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32031243

RESUMO

The formation of mixed-species social groups, whereby heterospecifics form and maintain either transient or stable groups with each other, can confer substantial fitness benefits to individuals. Such benefits may arise via multiple mechanisms associated with both predation avoidance and foraging efficiency. In fishes, mixed-species shoaling reportedly occurs where displaced tropical species (known as "vagrants") interact with resident temperate species, although little is known about the nature and frequency of such interactions. To investigate this phenomenon, we used displaced tropical Indo-pacific Sergeant Abudefduf vaigiensis settling in temperate south-eastern Australia as a model system. Underwater visual surveys revealed shoal composition and size differed significantly between open-water and reef habitats, with shoals in open habitats being larger and more speciose. Shoals containing A. vaigiensis were mainly mixed-species, and larger and more speciose in open habitats than nearer to reef. Since both foraging efficiency (via access to plankton) and predation threat likely increase with increasing distance from reef habitat, we suggest that mixed-species shoaling mitigates predation risk whilst allowing increased foraging opportunities for A. vaigiensis in open areas. These findings provide support for the importance of mixed-species shoaling to the persistence of tropical reef fishes in temperate regions.


Assuntos
Ecossistema , Comportamento Alimentar/fisiologia , Perciformes/fisiologia , Animais , Comportamento Predatório , Austrália do Sul
6.
J Fish Biol ; 96(4): 939-949, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32048298

RESUMO

We examined the reproductive life history of calico surfperch (Amphistichus koelzi), including mating season, pregnancy, gestation and multiple paternity utilizing restriction site-associated DNA sequencing. Furthermore, we compared the mating season of calico with barred (Amphistichus argenteus), walleye (Hyperprosopon argenteum) and silver (Hyperprosopon ellipticum) surfperches to determine if the timing of reproduction is divergent within and between the genera. In calico surfperch, the mating season occurs from October to November, and females gestate from December to May. All broods exhibit multiple paternity with a range of four to seven sires per brood. The mating season of calico overlaps completely with barred surfperch; however, barred surfperches have a protracted mating season which extends until the beginning of December, which may be due to differences in reproductive strategy such as size at first reproduction. In the genus, the Hyperprosopon mating season begins earlier than Amphistichus, with divergence in the onset of mating between Hyperprosopon congeners of approximately 1 month.


Assuntos
Perciformes/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Perciformes/genética , Reprodução , Estações do Ano , Análise de Sequência de DNA
7.
J Fish Biol ; 96(4): 1004-1013, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32060925

RESUMO

Larval dispersion rather than adult migration generally leads to the worldwide expansion of fishes. Species of the genus Gymnocanthus have expanded geographically while undergoing allopatric speciation. Of this genus, while Gymnocanthus tricuspis inhabits the Arctic Ocean and surrounding area, G. herzensteini and G. intermedius occur around northern Japan. Larval early life histories of G. herzensteini and G. intermedius from northern Japan and G. tricuspis from Unalaska Island were investigated to estimate their dispersal potential during larval stages. The larval and juvenile abundances of G. herzensteini and G. intermedius were highest in May in shallow sandy bottoms below 7 m in depth, and the body sizes were 9.7-34.6 mm notochord length (NL) and/or standard length (SL) in G. herzensteini and 8.4-46.7 mm NL and/or SL in G. intermedius. Two egg masses of G. tricuspis (1.92 ± 0.08 mm in diameter) and hatched larvae (6.20 ± 0.19 mm NL) were collected in March. Compared with other sculpins in previous studies, the body sizes of G. herzensteini and G. intermedius at hatch are large and at settlement are small, while both hatch and settlement sizes of G. tricuspis are much larger. Counting micro-increments between the hatch check and settlement marks in G. herzensteini and G. intermedius demonstrated that the pelagic larval durations for 2 weeks with an immature body suggests that these species cannot disperse widely during the pelagic phase, while pelagic larvae of Arctic species such as G. tricuspis with long pelagic larval durations could disperse.


Assuntos
Distribuição Animal/fisiologia , Perciformes/fisiologia , Animais , Tamanho Corporal , Ilhas , Japão , Perciformes/anatomia & histologia , Simpatria
8.
PLoS One ; 15(2): e0228454, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053624

RESUMO

In commercial wild capture pelagic fisheries it is common practice to crowd catches to high densities to allow efficient pumping onboard. Crowding during the final stages of purse seine capture for small pelagic species often results in intense and sustained behavioural escape responses. Such a response may trigger a shift in energy production from aerobic to anaerobic pathways and result in metabolic acid accumulation and exhaustion of intracellular reserves of ATP. Where there is insufficient time or opportunity to recover to physiological equilibrium before death, pre-mortem stress may be an important determinant of fillet quality, as has been shown for a variety of farmed fish species. However, there is currently a lack of knowledge related to the flesh quality implications of capture stress for wild captured species in European waters. Here we show that crowding results in a physiological stress response that has consequences for flesh quality in the wild captured species Atlantic mackerel (Scomber scombrus). Using small schools in tanks and aquaculture net pens in three separate experiments, we found crowding results in physiological changes in mackerel consistent with an acute stress response and anaerobic metabolism. Consequently, we found crowded fish had more acidic pre- and post-mortem muscle pH as well as indications of faster onset and strength of rigor mortis and increased cathepsin B & L activity. We examined fillet flesh quality after two and seven days of ice storage and found reduced green colouration, increased gaping (separation of muscle myotomes) and reduced textural firmness associated with fish which had been crowded. However, the effects on quality were dependant on experiment and/or storage time. These results indicate the potential of crowding capture stress to influence the flesh quality of an economically important species and may have important implications for the wild capture pelagic fishing industry.


Assuntos
Aglomeração , Pesqueiros , Músculos/fisiologia , Perciformes/fisiologia , Estresse Fisiológico , Animais , Autopsia , Produtos Pesqueiros/análise , Qualidade dos Alimentos , Concentração de Íons de Hidrogênio , Músculos/química , Músculos/patologia , Alimentos Marinhos/análise
9.
Proc Biol Sci ; 287(1918): 20192228, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31937224

RESUMO

Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish (Istiophorus platypterus) and striped marlin (Kajikia audax) when attacking schooling sardine prey. Behavioural results from high-speed videos showed that sailfish and striped marlin both regularly made rostrum contact with prey but displayed distinct strategies. Marlin used high-speed dashes, breaking schools apart, often contacting prey incidentally or tapping at isolated prey with their rostra; while sailfish used their rostra more frequently and tended to use a slower, less disruptive approach with more horizontal rostral slashes on cohesive prey schools. Capture success per attack was similar between species, but striped marlin had higher capture rates per minute. The rostra of both species are covered with micro-teeth, and micro-CT imaging showed that species did not differ in average micro-tooth length, but sailfish had a higher density of micro-teeth on the dorsal and ventral sides of their rostra and a higher amount of micro-teeth regrowth, suggesting a greater amount of rostrum use is associated with more investment in micro-teeth. Our analysis shows that the rostra of billfish are used in distinct ways and we discuss our results in the broader context of relationships between morphological and behavioural feeding adaptations across species.


Assuntos
Perciformes/anatomia & histologia , Comportamento Predatório , Animais , Evolução Biológica , Comportamento Alimentar , Perciformes/fisiologia
10.
PLoS One ; 15(1): e0228254, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978207

RESUMO

Warsaw grouper, Hyporthodus nigritus, is a western Atlantic Ocean species typically found at depths between 55 and 525 m. It is listed as a species of concern by the U.S. National Marine Fisheries Service and as near threatened by the International Union for the Conservation of Nature. However, little information exists on the species' life history in the northern Gulf of Mexico (nGOM) and its stock status in that region is currently unknown. Age of nGOM Warsaw grouper was investigated via opaque zone counts in otolith thin sections (max age = 61 y), and then the bomb 14C chronometer was employed to validate the accuracy of age estimates. Otolith cores (n = 14) were analyzed with accelerator mass spectrometry and resulting Δ14C values overlain on a loess regression computed for a regional coral and known-age red snapper Δ14C time series. Residual analysis between predicted Δ14C values from the loess regression versus Warsaw grouper otolith core Δ14C values indicated no significant difference in the two data series. Therefore, the accuracy of otolith-based aging was validated, which enabled growth and longevity estimates to be made for nGOM Warsaw grouper. Dissolved inorganic carbon (DIC) Δ14C values collected from the nGOM support the inference that juvenile Warsaw grouper occur in shelf waters (<200 m) since DIC Δ14C values in this depth range are enriched in 14C and similar to the Δ14C values from otolith cores. A Bayesian model was fit to fishery-dependent age composition data and produced von Bertalanffy growth function parameters of L∞ = 1,533 mm, k = 0.14 y-1, and t0 = 1.82 y. Fishing mortality also was estimated in the model, which resulted in a ratio of fishing to natural mortality of 5.1:1. Overall, study results indicate Warsaw grouper is a long-lived species that is estimated to have experienced significant overfishing in the nGOM, with the age of most landed fish being <10 y.


Assuntos
Membrana dos Otólitos/química , Perciformes/fisiologia , Datação Radiométrica/métodos , Animais , Teorema de Bayes , Radioisótopos de Carbono/química , Pesqueiros , Golfo do México , Longevidade , Espectrometria de Massas , Perciformes/crescimento & desenvolvimento
11.
PLoS One ; 15(1): e0224060, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31945056

RESUMO

De facto marine protected areas (DFMPAs) are regions of the ocean where human activity is restricted for reasons other than conservation. Although DFMPAs are widespread globally, their potential role in the protection of marine habitats, species, and ecosystems has not been well studied. In 2012 and 2013, we conducted remotely operated vehicle (ROV) surveys of marine communities at a military DFMPA closed to all civilian access since 2010 and an adjacent fished reference site at San Clemente Island, the southernmost of California's Channel Islands. We used data extracted from ROV imagery to compare density and biomass of focal species, as well as biodiversity and community composition, between the two sites. Generalized linear modeling indicated that both density and biomass of California sheephead (Semicossyphus pulcher) were significantly higher inside the DFMPA. Biomass of ocean whitefish (Caulolatilus princeps) was also significantly higher inside the DFMPA. However, species richness and Shannon-Weaver diversity were not significantly higher inside the DFMPA, and overall fish community composition did not differ significantly between sites. Demonstrable differences between the DFMPA and fished site for two highly sought-after species hint at early potential benefits of protection, though the lack of differences in the broader community suggests that a longer trajectory of recovery may be required for other species. A more comprehensive understanding of the potential conservation benefits of DFMPAs is important in the context of marine spatial planning and global marine conservation objectives.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Perciformes/fisiologia , Animais , California , Ilhas Anglo-Normandas , Peixes/fisiologia , Cadeia Alimentar , Atividades Humanas , Humanos , Ilhas , Densidade Demográfica
12.
J Fish Biol ; 96(1): 274-277, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760658

RESUMO

Response of orange-finned anemonefish Amphiprion chrysopterus and three-spot damselfish Dascyllus trimaculatus to red laser-pointer light was studied in Mo'orea, French Polynesia. Four magnificent anemones Heteractis magnifica and their resident fish were observed for typical behaviours (biting, chasing, hiding, posing, lunging and retreating) with and without exposure to laser-pointer light. Lunging behaviour increased significantly for both fish species upon exposure to laser-pointer light; none of the other behaviours changed significantly. We advance the hypothesis that orange-finned anemonefish and three-spot damselfish interpret laser pointer stimulation as a territorial threat.


Assuntos
Comportamento Animal/fisiologia , Luz/efeitos adversos , Perciformes/fisiologia , Animais , Recifes de Corais , Polinésia
13.
Environ Pollut ; 256: 113452, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31706763

RESUMO

Tasmanian recreational fishers have reported the presence of dark pigmentations in the usually white fillets of southern sand flathead (Platycephalus bassensis), a phenomenon known as muscle melanisation. Based on histology, it is suggested that eumelanin and pheomelanin are involved in the occurrence of the phenomenon. A gross melanisation scoring system was validated through a comparison with an image analysis technique, that quantified the percentage surface area of the fillets affected by muscle melanisation. The occurrence of muscle melanisation was most severe in fish inhabiting Deceitful Cove, Tamar Estuary. This indicated that muscle melanisation in P. bassensis may be caused by yet to be identified site specific factors. No significant relationships were evident between the percentage surface area of melanised muscle with condition index, age, sex, maturation stage, fish weight, fish length and size of melano-macrophage centres in the liver or spleen. Overall, this study has provided critical information that will frame the direction and focus of future P. bassensis muscle melanisation research.


Assuntos
Peixes/metabolismo , Perciformes/fisiologia , Poluentes Químicos da Água/metabolismo , Animais , Austrália , Monitoramento Ambiental , Estuários , Peixes/fisiologia , Fígado/química , Músculos/química , Areia , Tasmânia , Poluentes Químicos da Água/análise
14.
J Fish Biol ; 96(1): 92-101, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31661158

RESUMO

We compared the trophic niches of freshwater sculpins Cottus spp. with those of other co-habiting forage fishes in two groups of boreal lakes with distinct habitats and fish communities. Near North Lakes (45° 00' to 47° 30' N) were deeper, stratified and contained lake trout Salvelinus namaycush as the apex piscivore, whereas Far North Lakes (51° 10' to 52° 20' N) were shallower, did not stratify and contained pike Esox lucius and walleye Sander vitreus as the apex piscivores. Trophic niches of sculpins and other forage fishes were compared based on niche metrics calculated from muscle stable carbon (δ13 C) and nitrogen (δ15 N) isotope ratios. In Near North Lakes, sculpins were found almost exclusively in deep, offshore waters and their niche positions reflected a greater reliance on pelagic production (lower δ13 C) and a higher trophic elevation (higher δ15 N) compared with most other forage fishes. Furthermore, sculpins in Near North Lakes tended to have larger trophic niches (occupied greater area in δ13 C- δ15 N space), particularly in the food chain (δ15 N) dimension, than other cohabiting forage fishes. In contrast, sculpins in Far North Lakes were commonly found in the nearshore and had trophic niche positions and sizes that were similar to those of the other cohabiting forage fishes. This study illustrates the flexibility in the realised trophic niches of sculpins in relation to habitat availability and fish community composition in boreal lakes.


Assuntos
Cadeia Alimentar , Lagos , Perciformes/fisiologia , Animais , Canadá , Estado Nutricional
15.
C R Biol ; 342(9-10): 309-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31784218

RESUMO

Damselfishes of the genus Stegastes are among the most conspicuous benthic reef-associated fish in the Gulf of California, and the two most commonly found species are the Beaubrummel Gregory Stegastes flavilatus and the Cortez damselfish Stegastes rectifraenum. Both species are described as ecologically and morphologically very similar. However, the niche theory predicts that coexisting species will tend to minimize competition through niche partitioning. We, therefore, investigated the degree of their ecological similarity through their morphology, trophic ecology, and spatial distribution, as well as, the effects of environmental variables on their abundance. We showed that S. rectifraenum is highly abundant in the entire Gulf of California while S. flavilatus is only found in the central and southern part. The abundance of S. rectifraenum was higher in shallow water and decreased when the cover of macroalgae and sand increased. No environmental variable was related to the abundance of S. flavilatus. Both species had distinct isotopic niches: S. flavilatus fed almost exclusively on plankton and zoobenthos, while S. rectifraenum had an omnivorous diet mixing turf, zoobenthos and plankton. The diet divergence was reflected in the morphology of the two species. Stegastes flavilatus had a more rounded body shape, with a higher supraoccipital crest and more gill rakers than S. rectifraenum, which may increase its ability to feed on vagile invertebrates and zooplankton. Our results support the hypothesis that a niche partition has occurred between the two species. Furthermore, the importance of planktonic food sources to both species, considered as benthic territorial feeders, challenges the traditional ecological description of the Stegastes species.


Assuntos
Ecologia , Perciformes/fisiologia , Animais , Brânquias/fisiologia
16.
PLoS One ; 14(12): e0225552, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31887738

RESUMO

Predator-prey relations, as well as the trophic ecology of highly migratory marine species, is important to understand their impact on the ecosystem. Conventional methods were used to study the diet composition and feeding strategy of the Northeast Atlantic mackerel (Scombrus scomber), during their summer feeding migration to Icelandic waters in 2009-2014. In addition, generalised additive modelling (GAM) was used to determine which biological and environmental factors contribute to the variation of their stomach weight in the years 2011-2014. From the dietary analysis, we found that calanoid copepods (especially Calanus finmarchicus) were the most important contributor to the overall diet of mackerel in the years studied. Although in some years and areas, they also preyed heavily on larger prey items such as euphausiids, amphipods and megalopa larvae of crab and shrimp. The GAM showed that temperature and the time the day of sampling were significant explanatory variables for the stomach weight, while zooplankton biomass did not seem to have much influence. The Northeast Atlantic mackerel are ferocious feeders upon copepods, as well as exhibiting an overall opportunistic feeding strategy. During their feeding migration in Icelandic waters, they were found to feed on the most dominant species available to them.


Assuntos
Comportamento Alimentar/fisiologia , Cadeia Alimentar , Perciformes/fisiologia , Comportamento Predatório/fisiologia , Migração Animal/fisiologia , Animais , Regiões Árticas , Oceano Atlântico , Copépodes , Islândia , Larva , Modelos Biológicos , Estações do Ano , Temperatura , Fatores de Tempo , Zooplâncton
17.
BMC Evol Biol ; 19(1): 205, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694524

RESUMO

BACKGROUND: Antarctic fishes of the Notothenioidei suborder constitutively upregulate multiple inducible chaperones, a highly derived adaptation that preserves proteostasis in extreme cold, and represent a system for studying the evolution of gene frontloading. We screened for Hsf1-binding sites, as Hsf1 is a master transcription factor of the heat shock response, and highly-conserved non-coding elements within proximal promoters of chaperone genes across 10 Antarctic notothens, 2 subpolar notothens, and 17 perciform fishes. We employed phylogenetic models of molecular evolution to determine whether (i) changes in motifs associated with Hsf1-binding and/or (ii) relaxed purifying selection or exaptation at ancestral cis-regulatory elements coincided with the evolution of chaperone frontloading in Antarctic notothens. RESULTS: Antarctic notothens exhibited significantly fewer Hsf1-binding sites per bp at chaperone promoters than subpolar notothens and Serranoidei, the most closely-related suborder to Notothenioidei included in this study. 90% of chaperone promoters exhibited accelerated substitution rates among Antarctic notothens relative to other perciformes. The proportion of bases undergoing accelerated evolution (i) was significantly greater in Antarctic notothens than in subpolar notothens and Perciformes in 70% of chaperone genes and (ii) increased among bases that were more conserved among perciformes. Lastly, we detected evidence of relaxed purifying selection and exaptation acting on ancestrally conserved cis-regulatory elements in the Antarctic notothen lineage and its major branches. CONCLUSION: A large degree of turnover has occurred in Notothenioidei at chaperone promoter regions that are conserved among perciform fishes following adaptation to the cooling of the Southern Ocean. Additionally, derived reductions in Hsf1-binding site frequency suggest cis-regulatory modifications to the classical heat shock response. Of note, turnover events within chaperone promoters were less frequent in the ancestral node of Antarctic notothens relative to younger Antarctic lineages. This suggests that cis-regulatory divergence at chaperone promoters may be greater between Antarctic notothen lineages than between subpolar and Antarctic clades. These findings demonstrate that strong selective forces have acted upon cis-regulatory elements of chaperone genes among Antarctic notothens.


Assuntos
Evolução Molecular , Proteínas de Peixes/genética , Chaperonas Moleculares/genética , Perciformes/genética , Perciformes/fisiologia , Regiões Promotoras Genéticas , Adaptação Fisiológica , Animais , Regiões Antárticas , Regulação da Expressão Gênica , Resposta ao Choque Térmico , Filogenia
18.
Mar Biotechnol (NY) ; 21(6): 791-805, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31741169

RESUMO

The large yellow croaker Larimichthys crocea is an economically important marine fish species endemic to China and East Asia. Ningde area of Fujian Province is a major L. crocea aquaculture and spawning center in China. L. crocea cultivated at the Zhoushan area appears to be popular but suffered high mortality in cold water during winter seasons. To reduce the mortality rate, we pretreated fish with cold shocks prior to shift to cold water. In this study, we show that cold-pretreated L. crocea 12 days after shift to cold water increase the viability by 5.77-fold compared to the unpretreated (live fish 75 versus 13, p value = 1.775e-06, n = 100). The highest loss of 31 out of 100 fish in the unpretreated group occurred in day 3 after temperature shift. To identify the pretreatment-induced transcriptional changes that may be attributed to cold-resistance and survival, we performed RNA-seq analysis of a total of 48 fish that were prior to and 48 h, 54 h, and 72 h after temperature shift in pretreated and unpretreated groups in sextuplicate. Transcriptomic profiling analysis indicates that pretreatment-induced transcriptional alterations of enzymes involved in FASI, ß-oxidation, PUFA synthesis, oxidative phosphorylation, and molecular chaperones persisted after temperature shift, suggesting that these metabolic pathways may play a role in L. crocea cold-resistance and survival. Our study provides insights on how the pretreatment enhances the L. crocea growth fitness in cold water.


Assuntos
Aquicultura/métodos , Temperatura Baixa/efeitos adversos , Perciformes/crescimento & desenvolvimento , Perciformes/fisiologia , Animais , Perciformes/metabolismo , Análise de Sequência de RNA , Transcriptoma
19.
Environ Pollut ; 255(Pt 2): 113333, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610518

RESUMO

Arsenic (As) is a metalloid element that is ubiquitous in the marine environment and its contamination has received worldwide attention due to its potential toxicity. Arsenic can induce multiple adverse effects, such as lipid metabolism disorder, immune system dysfunction, oxidative stress and carcinogenesis, in animals. Inorganic arsenic includes two chemical forms, arsenite (As (III)) and arsenate (As (V)), in natural environment. As (V) is the dominant form in natural waters. In the present study, metabolomic and proteomic alterations were investigated in juvenile rockfish Sebastes schlegelii exposed to environmentally relevant concentrations of As (V) for 14 d. The analysis of iTRAQ-based proteomics combined with untargeted NMR-based metabolomics indicated apparent toxicological effects induced by As (V) in juvenile rockfish. In details, the metabolites, including lactate, alanine, ATP, inosine and phosphocholine were significantly altered in As-treated groups. Proteomic responses suggested that As (V) could not only affected energy and primary metabolisms and signal transduction, but also influenced cytoskeleton structure in juvenile rockfish. This work suggested that the combined proteomic and metabolomic approach could shed light on the toxicological effects of pollutants in rockfish S. schlegelii.


Assuntos
Arsênico/toxicidade , Perciformes/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Arseniatos , Arsenitos , Bass/fisiologia , Metabolômica , Estresse Oxidativo/efeitos dos fármacos , Proteômica
20.
Mar Pollut Bull ; 145: 418-428, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590805

RESUMO

Pollution threats Antarctica and scientists blame xenobiotics and anthropic activities. Yet little is known about their effect on Antarctic ichthyofauna. Accordingly, we investigated the endocrine system of male fish Notothenia rossii and N. coriiceps (Perciformes, Nototheniidae) collected during Austral summer. For N. rossii, hormone levels of estradiol, testosterone, and 11-ketotestosterone were higher in fish collected during March than those of January; whereas for N. coriiceps estradiol and androgens levels were higher and lower in March, respectively. Histological analysis of the testes showed an unrestricted lobular type with no pathological alterations. However, detection of vitellogenin-like in plasma and skin mucus were seen in 75% of N. coriiceps males and 7% of N. rossii males. This is the first report of mucus vitellogenin-like detection as a non-invasive biomarker of endocrine disruption in notothenioid males and settles a baseline for future studies of reproductive biology and endocrine disruption in Antarctic fishes.


Assuntos
Sistema Endócrino/metabolismo , Perciformes/fisiologia , Reprodução/efeitos dos fármacos , Poluentes da Água/toxicidade , Animais , Regiões Antárticas , Ecotoxicologia , Sistema Endócrino/efeitos dos fármacos , Monitoramento Ambiental , Estradiol/metabolismo , Feminino , Masculino , Perciformes/crescimento & desenvolvimento , Testosterona/análogos & derivados , Testosterona/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA