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1.
J Environ Sci (China) ; 148: 230-242, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095160

RESUMO

Fish constitutes the main protein source for the Amazonian population. However, the impact of different anthropogenic activities on trace element and metal accumulation in fish and their risks for human health at a regional scale remain largely unexplored. Here we assessed exposure levels of 10 trace elements and metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Pb, and Hg) in 56 samples belonging to 11 different species of fish from the Brazilian Amazon. We studied the relationship between exposure levels, fish origin, and fish feeding habits, and assessed toxicological and carcinogenic risks for the Amazonian population. No significant correlation was found between sampling site and exposure levels to the studied elements, but a significant difference was found between the accumulation of some metals and the position of the fish species in the food chain. The concentrations of Cr and Hg in fish flesh were found to exceed the Brazilian limits for human consumption. This study shows that current fish consumption patterns can lead to estimated daily intakes of Hg, As and Cr that exceed the oral reference dose, thus posing a toxicological concern. Furthermore, carcinogenic risks may be expected due to the continued exposure to Cr and As. The results of this study show that the consumption of wild caught fish in the Amazon region should be controlled. Moreover, continued monitoring of trace element and metal contamination in fish and on the health of the Amazonian population is recommended, particularly for riverine and indigenous communities.


Assuntos
Peixes , Contaminação de Alimentos , Metais , Oligoelementos , Poluentes Químicos da Água , Animais , Brasil , Humanos , Poluentes Químicos da Água/análise , Oligoelementos/análise , Contaminação de Alimentos/análise , Medição de Risco , Metais/análise , Monitoramento Ambiental
2.
Glob Chang Biol ; 30(10): e17534, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39412116

RESUMO

Recent decades have witnessed substantial changes in freshwater biodiversity worldwide. Although research has shown that freshwater biodiversity can be shaped by changes in habitat diversity and human-induced pressure, the potentials for interaction between these drivers and freshwater biodiversity at large spatial extents remain unclear. To address these issues, we employed a spatially extensive multitrophic fish and insect database from 3323 stream sites across the United States, to investigate the ability of habitat diversity to modulate the effect of human pressure on the richness and abundance of fish and insects. We found evidence that high levels of habitat diversity were associated with increased richness and abundance of fish and insects (including whole-assemblage and individual trophic guilds). We also show that the effects of human pressure on the richness and abundance of fish and insects tend to become positive at high levels of habitat diversity. Where habitat diversity is low, human pressure strongly reduces insect richness and abundance, whereas these reductions are attenuated at high levels of habitat diversity. Structural equation modeling revealed that human pressure reduced habitat diversity, indirectly negatively affecting the richness and abundance of fish and insects. These findings illustrate that, in addition to promoting greater fish and insect biodiversity, habitat diversity may mitigate the deleterious effects of human pressures on these two stream assemblages. Overall, our study suggests that maintaining high levels of habitat diversity is a useful way to protect freshwater biodiversity from ongoing increases in human pressure. However, if human pressures continue to increase, this will reduce habitat diversity, further threatening stream assemblages.


Assuntos
Biodiversidade , Ecossistema , Peixes , Insetos , Rios , Animais , Insetos/fisiologia , Peixes/fisiologia , Estados Unidos , Humanos , Atividades Humanas
3.
Mol Genet Genomics ; 299(1): 96, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39382723

RESUMO

DNA transposons are diverse in fish genomes and have been described to generate genomic evolutionary novelties. hAT transposable element data are scarce in Teleostei genomes, making it challenging to conduct comparative genomic studies to understand their neutrality or function. This study aimed to perform a genomic and molecular characterization of hAT copies to assess the diversity of these elements and associate changes in these sequences to genomic and karyotypic novelties in Apareiodon sp. The data revealed that hAT TEs are highly abundant in the Apareiodon sp. genome, with few possibly autonomous copies. Highly conserved sequences with likely functional transposases were observed in nine hAT elements. A great diversity of hAT subgroups was observed, especially from Ac, Charlie, Blackjack, Tip100, hAT6, and hAT5, and a similar wave of hAT genomic invasion was identified in the genome for these six groups of hAT sequences. The data also revealed a distinct number of microsatellites within degenerated hAT copies. hAT sites were demonstrated to be dispersed in the Apareiodon sp. chromosomes and not involved in W chromosome-specific region differentiation. In conclusion, the genomic analysis revealed a great diversity of hAT elements, possible autonomous copies, and differentiation of degenerated transposable elements into tandem sequences.


Assuntos
Elementos de DNA Transponíveis , Genoma , Filogenia , Elementos de DNA Transponíveis/genética , Animais , Genoma/genética , Evolução Molecular , Repetições de Microssatélites/genética , Genômica/métodos , Peixes/genética , Peixes/classificação
4.
J Anim Ecol ; 93(11): 1771-1784, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39354751

RESUMO

Diversity and interspecific synchrony are among the main drivers behind the temporal stability of community abundance. Diversity can increase stability through the portfolio effect, while higher synchrony generally decreases stability. In turn, species interactions and similar responses to environmental variation are considered the main factors underlying the strength of interspecific synchrony, despite the challenges in determining their relative roles. The analysis of the relationship between interspecific synchrony and the trait (or phylogenetic) distance between species can increase the robustness of inferences about these factors. Here, we used pairwise interspecific and community-wide analyses to investigate, respectively, the drivers of interspecific synchrony and the influence of trait and phylogenetic diversity on the stability of fish communities. For that, we used 18 years of fish abundance data from the Upper Paraná River floodplain. At the interspecific level, we used quantile regressions to test within-guild relationships between interspecific synchrony and trait and phylogenetic distance between species. At the community level, we tested the relationships between community-wide synchrony, stability, and (trait and phylogenetic) diversity. We found that interspecific synchrony decreased with trait and phylogenetic distances. In the community-level analysis, we found that more synchronous fish communities were less stable, but the relationship between diversity and stability was in general weak. At the interspecific level, our study highlights the role of similar responses to environmental variation in driving species' temporal dynamics. At the community level, the strength of the relationships between trait or phylogenetic diversity and community stability depended on the feeding guild. On the other hand, we found strong relationships between synchrony and stability. These results suggest that increased synchrony levels in response to regional environmental changes could decrease the stability of fish communities in this floodplain.


Assuntos
Biodiversidade , Peixes , Filogenia , Rios , Animais , Peixes/fisiologia , Brasil , Dinâmica Populacional
5.
Int. j. cardiovasc. sci. (Impr.) ; 37(suppl.9): 42-42, oct., 2024.
Artigo em Português | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1577437

RESUMO

RESUMO: A ingestão de peixes como barracudas, moreias e garoupas pode causar intoxicação por ciguatera, toxina proveniente de microrganismos unicelulares do gênero Gambierdiscus. A ciguatoxina é inodora, insípida e afeta canais de sódio e potássio, provocando neurotoxicidade e cardiotoxicidade. Sintomas neurológicos e gastrointestinais são mais comuns, enquanto as manifestações cardiovasculares, como bradicardia, arritmia e hipotensão, são geralmente transitórias. Relatamos um caso raro de bradicardia grave e miocardite associadas à ciguatera. RELATO DE CASO: Paciente masculino, 64 anos, maratonista, foi admitido em hospital em Fernando de Noronha após ingestão de peixe de pesca local, com diarreia volumosa, sudorese, parestesia, vertigem e lipotimia. Apresentava bradicardia (23 bpm) e instabilidade hemodinâmica, sendo necessária atropina e hidratação. Após três dias, recebeu alta com FC de 40-45 bpm. Procurou atendimento em Brasília por tontura, bradicardia sinusal persistente (34 bpm) e alterações da repolarização ventricular. O ecocardiograma mostrou aumento biatrial e fração de ejeção limítrofe, com hipocinesia inferolateral. Aressonância magnética (RMC) mostrou realce mesoepicárdico compatível com miocardite aguda (mapa T2 alterado), e o holter indicou bradicardia (FCm 40 bpm). Após 9 dias de internação, os sintomas se resolveram. Em reavaliação, apresentou FC média de 60 bpm, mas foram observadas 2.748 extra-sístoles ventriculares polimórficas isoladas, sequela da miocardite, que causou 3,5% de fibrose no ventrículo. Aangiotomografia revelou placa com estenose de 20%, sem calcificações. O paciente segue em acompanhamento, sem novas intercorrências. Sua esposa, que compartilhou a mesma alimentação, também apresentou sintomas, mas não necessitou atendimento hospitalar. CONCLUSÃO: Aciguatera é uma doença pouco conhecida e subdiagnosticada. Este caso destaca a importância dessa hipótese diagnóstica em pacientes com déficit cronotrópico após viagem a regiões endêmicas. A RMC foi essencial para o diagnóstico de miocardite e para a recomendação de evitar esforço por 6 meses, prevenindo arritmias e óbito. Foi realizada notificação à Secretaria de Saúde para orientar a população de Fernando de Noronha e turistas.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Arritmias Cardíacas , Bradicardia , Ciguatoxinas , Emergências , Peixes , Cardiotoxicidade
6.
J Hazard Mater ; 479: 135638, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39217937

RESUMO

Microplastics in aquatic ecosystems harbor numerous microorganisms, including pathogenic species. The ingestion of these microplastics by commercial fish poses a threat to the ecosystem and human livelihood. Coastal lagoons are highly vulnerable to microplastic and microbiological pollution, yet limited understanding of the risks complicates management. Here, we present the main bacterial groups, including potentially pathogenic species, identified on microplastics in waters, sediments, and commercial fish from Ciénaga Grande de Santa Marta (CGSM), the largest coastal lagoon in Colombia. DNA metabarcoding allowed identifying 1760 bacterial genera on microplastics, with Aeromonas and Acinetobacter as the most frequent and present in all three matrices. The greatest bacterial richness and diversity were recorded on microplastics from sediments, followed by waters and fish. Biochemical analyses yielded 19 species of potentially pathogenic culturable bacteria on microplastics. Aeromonas caviae was the most frequent and, along with Pantoea sp., was found on microplastics in all three matrices. Enterobacter roggenkampii and Pseudomonas fluorescens were also found on microplastics from waters and fish. We propose management strategies for an Early Warning System against microbiological and microplastic pollution risks in coastal lagoons, illustrated by CGSM. This includes forming inter-institutional alliances for research and monitoring, accompanied by strengthening governance and health infrastructures.


Assuntos
Bactérias , Sedimentos Geológicos , Microplásticos , Animais , Sedimentos Geológicos/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Peixes/microbiologia , Poluentes Químicos da Água/análise , Colômbia , Monitoramento Ambiental , Microbiologia da Água , Água do Mar/microbiologia
7.
Mar Drugs ; 22(9)2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39330303

RESUMO

We describe five new isolates of two Gambierdiscus species from Bahía de La Paz in the southern Gulf of California. Batch cultures of Gambierdiscus were established for morphological characterization using light microscopy (LM) and scanning electron microscopy (SEM). Pigment and amino acid profiles were also analyzed using high-performance liquid chromatography (HPLC-UV and HPLC-DAD). Finally, toxicity (CTX-like and MTX-like activity) was evaluated using the Artemia salina assay (ARTOX), mouse assay (MBA), marine fish assay (MFA), and fluorescent receptor binding assay (fRBA). These strains were identified as Gambierdiscus cf. caribaeus and Gambierdiscus cf. carpenteri. Toxicity for CTX-like and MTX-like activity was confirmed in all evaluated clones. Seven pigments were detected, with chlorophyll a, pyridine, Chl2, and diadinoxanthin being particularly noteworthy. For the first time, a screening of the amino acid profile of Gambierdiscus from the Pacific Ocean was conducted, which showed 14 amino acids for all strains except histidine, which was only present in G. cf. caribeaus. We report the presence of Gambierdiscus and Fukuyoa species in the Mexican Pacific, where ciguatera fish poisoning (CFP) cases have occurred.


Assuntos
Dinoflagellida , Animais , Camundongos , Dinoflagellida/química , Aminoácidos/análise , Cromatografia Líquida de Alta Pressão , Artemia/efeitos dos fármacos , Ciguatoxinas/toxicidade , Ciguatera , Peixes/parasitologia
8.
Parasite ; 31: 55, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39311469

RESUMO

We propose and describe Alobophora sandrae Cajiao-Mora & Bullard n. gen., n. sp. (Digenea: Caballerotrematidae) for specimens we collected from arapaima, Arapaima gigas sensu lato (Osteoglossiformes: Arapaimidae) in the Amazon River near Leticia, Colombia. Alobophora differs from Caballerotrema Prudhoe, 1960 by lacking head collar projections and by having clustered corner spines and a narrow head collar (4-5× wider than pharynx), whereas Caballerotrema has head collar projections, lacks clustered corner spines, and has a broad head collar (7-8× wider than pharynx). We reassign Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez & Sattmann, 2002 to the new genus, as Alobophora annulata (Diesing, 1850) Cajiao-Mora and Bullard n. comb., and provide a supplemental description of Caballerotrema brasiliense Prudhoe, 1960 based on specimens we collected from arapaima. We also examined the holotype and a paratype of Caballerotrema piscicola (Stunkard, 1960) Kostadinova & Gibson, 2001 and concluded that C. piscicola is a junior subjective synonym of C. brasiliense. Our 28S phylogeny recovered A. sandrae sister to A. annulata, with that clade sister to a clade comprising C. brasiliense and an innominate species of Caballerotrema. Caballerotrematidae was recovered sister to Echinostomatidae. We also provide a dichotomous key to caballerotrematids based on head collar projections, corner spine arrangement, proportional pharynx and head collar breadth, testes shape and arrangement, body surface spine shape and distribution, vitellarium distribution, and abundance of prostatic cells.


Title: Alobophora sandrae n. gen. n. sp. (Digenea : Caballerotrematidae) infectant Arapaima gigas sensu lato (Osteoglossiformes : Arapaimidae) avec une révision de Caballerotrema, une clé des Caballerotrematidae et une phylogénie mise à jour. Abstract: Nous proposons et décrivons Alobophora sandrae Cajiao-Mora & Bullard n. gen., n. sp. (Digenea : Caballerotrematidae) pour les spécimens que nous avons collectés chez l'arapaïma, Arapaima gigas sensu lato (Osteoglossiformes : Arapaimidae) dans le fleuve Amazone près de Leticia (Colombie). Alobophora diffère de Caballerotrema Prudhoe, 1960 par l'absence de projections du collier céphalique et par la présence d'épines angulaires groupées et d'un collier céphalique étroit (4 à 5 fois plus large que le pharynx), tandis que Caballerotrema présente des projections du collier céphalique, n'a pas d'épines angulaires groupées et a un collier céphalique large (7 à 8 fois plus large que le pharynx). Nous réaffectons Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez & Sattmann, 2002 au nouveau genre, sous le nom d'Alobophora annulata (Diesing, 1850) Cajiao-Mora et Bullard n. comb., et fournissons une description supplémentaire de Caballerotrema brasiliense Prudhoe, 1960 basée sur des spécimens que nous avons collectés sur des arapaïmas. Nous avons également examiné l'holotype et un paratype de Caballerotrema piscicola (Stunkard, 1960) Kostadinova & Gibson, 2001 et avons conclu que C. piscicola est un synonyme subjectif junior de C. brasiliense. Notre phylogénie 28S a trouvé A. sandrae groupe-frère d'A. annulata, avec ce clade frère d'un clade comprenant C. brasiliense et une espèce non nommée de Caballerotrema. Les Caballerotrematidae ont été trouvés comme groupe-frère des Echinostomatidae. Nous fournissons également une clé dichotomique des Caballerotrematidae basée sur les projections du collier de la tête, la disposition des épines d'angle, la largeur proportionnelle du pharynx et du collier de la tête, la forme et la disposition des testicules, la forme et la distribution des épines de la surface du corps, la distribution du vitellarium et l'abondance des cellules prostatiques.


Assuntos
Doenças dos Peixes , Filogenia , Rios , Trematódeos , Infecções por Trematódeos , Animais , Trematódeos/classificação , Trematódeos/anatomia & histologia , Trematódeos/genética , Trematódeos/isolamento & purificação , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia , Doenças dos Peixes/parasitologia , Colômbia , Peixes/parasitologia , RNA Ribossômico 28S/genética
9.
Glob Chang Biol ; 30(9): e17513, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39319475

RESUMO

Human activities and climate change have accelerated species losses and degradation of ecosystems to unprecedented levels. Both theoretical and empirical evidence suggest that extinction cascades contribute substantially to global species loss. The effects of extinction cascades can ripple across levels of ecological organization, causing not only the secondary loss of taxonomic diversity but also functional diversity erosion. Here, we take a step forward in coextinction analysis by estimating the functional robustness of reef fish communities to species loss. We built a tripartite network with nodes and links based on a model output predicting reef fish occupancy (113 species) as a function of coral and turf algae cover in Southwestern Atlantic reefs. This network comprised coral species, coral-associated fish (site occupancy directly related to coral cover), and co-occurring fish (occupancy indirectly related to coral cover). We used attack-tolerance curves and estimated network robustness (R) to quantify the cascading loss of reef fish taxonomic and functional diversity along three scenarios of coral species loss: degree centrality (removing first corals with more coral-associated fish), bleaching vulnerability and post-bleaching mortality (most vulnerable removed first), and random removal. Degree centrality produced the greatest losses (lowest R) in comparison with other scenarios. In this scenario, while functional diversity was robust to the direct loss of coral-associated fish (R = 0.85), the taxonomic diversity was not robust to coral loss (R = 0.54). Both taxonomic and functional diversity showed low robustness to indirect fish extinctions (R = 0.31 and R = 0.57, respectively). Projections of 100% coral species loss caused a reduction of 69% of the regional trait space area. The effects of coral loss in Southwestern Atlantic reefs went beyond the direct coral-fish relationships. Ever-growing human impacts on reef ecosystems can cause extinction cascades with detrimental consequences for fish assemblages that benefit from corals.


Assuntos
Biodiversidade , Mudança Climática , Recifes de Corais , Extinção Biológica , Peixes , Animais , Peixes/fisiologia , Antozoários/fisiologia
10.
Parasitol Res ; 123(9): 328, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39297998

RESUMO

This study examined the metrics of the macroparasite community in fishes from the Jaguaribe River basin, state of Ceará, before and after receiving water from the São Francisco River in Northeastern Brazil. This research assessed the association of environmental factors (water parameters) and the traits of 30 fish species on the parasite richness and abundance across space (river course) and time (seasons, pre- and post-transposition periods). Generalized linear models reveal associations between parasite metrics and host traits, water parameters, and river sub-basin. Host size and body condition positively correlated with parasite richness and abundance, while reproductive phase was negatively related. Water quality impacted ecto- and endoparasites differently, with seasonal and sub-basins variations and differences among sub-basins. The general models also indicate that the period is a significant variable, where parasite richness decreases while abundance increases in the post-transposition period. This study underscores the importance of considering diverse environmental and host variables for understanding parasite dynamics in river ecosystems. These findings could lead to valuable insights for ecosystem management and conservation, elucidating the potential consequences of environmental alterations on parasite-host interactions and ecosystem health.


Assuntos
Biodiversidade , Doenças dos Peixes , Peixes , Parasitos , Rios , Animais , Brasil , Rios/parasitologia , Peixes/parasitologia , Parasitos/classificação , Parasitos/isolamento & purificação , Doenças dos Peixes/parasitologia , Estações do Ano , Ecossistema , Doenças Parasitárias em Animais/parasitologia , Doenças Parasitárias em Animais/epidemiologia
11.
J Anim Ecol ; 93(10): 1442-1444, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39275885

RESUMO

The variance-mean scaling in population abundance or Taylor's power law (TPL) has been reported hundreds of times and is related to ecological processes such as competition, dispersal or territoriality. In this sense, the TPL was extensively validated to resume population variability and to show the action of ecological mechanisms. Baumgartner and Peláez (2024) combine databases of fish dynamics along the United States, species traits, species phylogeny and climatic conditions, estimating the TPL for 180 species along 972 populations. The observed scaling suggests that the variability of the population decreases with abundance. Notably, 68% of the variation in the variance-mean scaling was explained by species traits and environmental conditions. Specifically, the life history of the species, associated with its body size, was the main explanation for the TPL, also reporting that the variability of the population increased faster with mean abundance in the headwaters than in other river sections. Equally important, the diversity of the community in which the species were inserted did not affect the scaling. These results provide overwhelming evidence on the nature of TPL on large geographic scales and how they are affected by species biology and environmental conditions. A contribution that should motivate further empirical and theoretical analysis of the TPL and its determinants.


El escalamiento en varianza con la media de la abundancia poblacional, ha sido reportado en cientos de sistemas y es conocido como Ley Poder de Taylor (TPL, de sus siglas en inglés). Este escalamiento se ha relacionado con la importancia de la competencia, dispersión o territorialidad, resumiendo la dinámica poblacional y su conexión con distintos mecanismos ecológicos. El estudio publicado por Baumgartner y Peláez (2024) combina bases de datos de dinámica de peces en los Estados Unidos de América, de sus rasgos, filogenia y ambientales, estimando la TPL para un total de 180 especies a lo largo de 972 poblaciones. El escalamiento observado sugiere que la variabilidad disminuye con la abundancia de las poblaciones. Notablemente, el 68% de la variación en el escalamiento fue explicado por los rasgos de las especies (historia de vida y tamaño corporal) y las condiciones ambientales. Aumentando más rápidamente la variabilidad en la dinámica poblacional con la abundancia media en las cabeceras que en otras secciones del río. Igualmente importante fue la falta de efectos significativos de la biodiversidad de la comunidad sobre el escalamiento varianza­media de sus poblaciones. Estos resultados proporcionan una contundente evidencia sobre la naturaleza de la TPL en grandes escalas geográficas y cómo se ve afectada por la biología de las especies y las condiciones ambientales. Resultados y abordajes que sugieren futuros análisis empíricos y teóricos sobre la TPL y sus determinantes.


Assuntos
Peixes , Dinâmica Populacional , Animais , Peixes/fisiologia , Densidade Demográfica , Características de História de Vida , Rios , Modelos Biológicos , Estados Unidos , Meio Ambiente
12.
Sci Rep ; 14(1): 22366, 2024 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-39333691

RESUMO

The increase in the construction of mega dams in tropical basins is considered a threat to freshwater fish diversity. Although difficult to detect in conventional monitoring programs, rheophilic species and those reliant on shallow habitats comprise a large proportion of fish diversity in tropical basins and are among the most sensitive species to hydropower impacts. We used Baited Remote Underwater Video (BRUV), an innovative, non-invasive sampling technique, to record the impacts caused by Belo Monte, the third largest hydropower project in the world, on fishes inhabiting fast waters in the Xingu River. BRUV were set in a river stretch of ~ 240 km for 7 years, 2 before and 5 after the Belo Monte operation. We explored the spatial and temporal variation in fish diversity (α, ß, and γ) and abundance (MaxN) using generalized additive models. We also investigated the variation of environmental variables and tested how much information we gained by including them in the diversity and abundance models. Belo Monte altered the flow regime, water characteristics, and fishery yield in the Xingu, resulting in changes in the fish community structure. Temporally, we observed sharp declines in α diversity and abundance, far exceeding those from a previous study conducted with more conventional sampling methods (i.e., catch-based) in the region. γ-diversity was also significantly reduced, but we observed a non-expected increase in ß diversity over time. The latter may be associated with a reduction in river connectivity and an increase in environmental heterogeneity among river sectors. Unexpected signs of recovery in diversity metrics were observed in the last years of monitoring, which may be associated with the maintenance of flow levels higher than those previously planned. These results showed that BRUV can be a useful and sensitive tool to monitor the impacts of dams and other enterprises on fish fauna from clear-water rivers. Moreover, this study enhances our comprehension of the temporal variations in freshwater fish diversity metrics and discusses the prevalent assumption that a linear continuum in fish-structure damage associated with dam impoundments may exhibit temporal non-linearity.


Assuntos
Biodiversidade , Peixes , Centrais Elétricas , Rios , Animais , Peixes/fisiologia , Ecossistema , Brasil , Monitoramento Ambiental/métodos
13.
Fish Physiol Biochem ; 50(6): 2505-2517, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39235532

RESUMO

Recently, hypoxic areas have been identified in water bodies of the Pampas region due to human activity. The objective of this work was to study the effect of low concentrations of dissolved oxygen (hypoxia) on the reproductive endocrine axis of a pampas fish (Odontesthes bonariensis). Groups of 8 males and 8 females were subjected to severe hypoxia (2-3 mg l-1) and normoxia (7-9 mg l-1) in 3000 l tanks by duplicate during the reproductive season (spring). After 21 days, 4 males and 4 females from each tank were sacrificed, and blood was drawn to measure estradiol (E2) and testosterone (T). The brain, pituitary gland and a portion of the gonads were extracted and processed to measure the expression of: gnrh1, cyp19a1b, fshß, lhß, fshr, lhcgr and cyp19a1a. From the second experimental week, no spawning was found in the hypoxic females, while at the end of the treatment period no male released sperm. Fish under hypoxic conditions showed signs of gonadal regression, reduction of GSI and plasma levels of sex steroids. Furthermore, the expression of gnrh1 in both sexes, cyp19a1b and fshr in males and only fshß and cyp19a1a in females decreased in comparison with normoxic fish. After 40 days under normal conditions, signs of reproductive recovery were observed in the treated fish. The results obtained demonstrated that hypoxia generated an inhibition of some components of the pejerrey's reproductive endocrine axis, but the effect was reversible.


Assuntos
Testosterona , Animais , Masculino , Feminino , Testosterona/sangue , Hipóxia/veterinária , Estradiol/sangue , Aromatase/metabolismo , Aromatase/genética , Reprodução/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Peixes/fisiologia , Sistema Endócrino/efeitos dos fármacos , Hipófise/metabolismo , Hipófise/efeitos dos fármacos , Oxigênio/sangue , Oxigênio/metabolismo , Gônadas/efeitos dos fármacos
14.
Braz J Biol ; 84: e286429, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39292143

RESUMO

This study was carried out to analyze the fatty acid and amino acid compositions of three economically important freshwater fish species, Mali (Wallago attu), Raho (Labeo rohita), and Mahseer (Tor putitora), indigenous to Indus River, Pakistan.. Amino acid profiling was done by high-performance liquid chromatography (HPLC) while gas chromatography (GC) was used for fatty acid analysis. Glutamic acid, aspartic acid, arginine, alanine, leucine, lysine and isoleucine were the most predominant amino acid while palmitic acid (C16:0), oleic acid (C18:1c), palmitoliec acid (C16:1c), linolenic acids (C18:2c) and docosahexaenoic acids (DHA C22:6) were the notable fatty acids present in these species. Our results indicated that all species have comparable nutritional composition and are good source of healthy human diet. Our findings will help the people to make informed choice while selecting fish for consumption and will pave the way for future researchers in planning new strategies to enhance the growth and production of commercial fish species. It will also be helpful for theFrom the current finding it was concluded that all fish species under discussion are rich in amino acids and fatty acids. These species contain essential amino acids and important fatty acid such as omega3 and omega 6, thus raising the nutritional quality of these species.


Assuntos
Aminoácidos , Ácidos Graxos , Rios , Animais , Aminoácidos/análise , Ácidos Graxos/análise , Paquistão , Rios/química , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Peixes/classificação , Cyprinidae/classificação
15.
Braz J Biol ; 84: e282002, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39292138

RESUMO

Healthy fish populations lead to healthy aquatic ecosystems and it is our responsibility to be a part of the solution. Fish is one of the most favored foods and is suitable for people of all ages. Fish is an essential source of protein, vitamins, and minerals and a source of income for millions of people. Human population growth and climate change are putting a strain on our food system, demanding the development of sustainable services to enhance global food production and its security. Food safety is an intricate problem in both developed and developing countries. Fresh fish is a highly perishable food with a limited life span; as a result, it must be delivered and kept carefully to minimize deterioration and assure safety. Fish spoilage is linked to biochemical changes that occur post-harvest, such as storage and transportation. These modifications can account for fish spoilage by altering the taste, texture, and appearance. Fish harvesting, distribution, and post-harvest handling are all unhygienic, resulting in poor and unpredictable fish quality in the market. Many innovative and effective control measurements of various bacteria in fish have been proposed and evaluated. This review is a systematic approach to investigating post-harvest fish spoilage, its assessment, and control strategies.


Assuntos
Peixes , Animais , Peixes/microbiologia , Microbiologia de Alimentos , Contaminação de Alimentos/análise , Bactérias/classificação , Bactérias/isolamento & purificação , Alimentos Marinhos/microbiologia , Humanos
16.
Food Microbiol ; 124: 104617, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39244369

RESUMO

This study aimed to assess the bacterial microbiota involved in the spoilage of pacu (Piaractus mesopotamics), patinga (female Piaractus mesopotamics x male Piaractus brachypomus), and tambacu (female Colossoma macropomum × male Piaractus mesopotamics) during ice and frozen storage. Changes in the microbiota of three fish species (N = 22) during storage were studied through 16S rRNA amplicon-based sequencing and correlated with volatile organic compounds (VOCs) and metabolites assessed by nuclear magnetic resonance (NMR). Storage conditions (time and temperature) affected the microbiota diversity in all fish samples. Fish microbiota comprised mainly of Pseudomonas sp., Brochothrix sp., Acinetobacter sp., Bacillus sp., Lactiplantibacillus sp., Kocuria sp., and Enterococcus sp. The relative abundance of Kocuria, P. fragi, L. plantarum, Enterococcus, and Acinetobacter was positively correlated with the metabolic pathways of ether lipid metabolism while B. thermosphacta and P. fragi were correlated with metabolic pathways involved in amino acid metabolism. P. fragi was the most prevalent spoilage bacteria in both storage conditions (ice and frozen), followed by B. thermosphacta. Moreover, the relative abundance of identified Bacillus strains in fish samples stored in ice was positively correlated with the production of VOCs (1-hexanol, nonanal, octenol, and 2-ethyl-1-hexanol) associated with off-flavors. 1H NMR analysis confirmed that amino acids, acetic acid, and ATP degradation products increase over (ice) storage, and therefore considered chemical spoilage index of fish fillets.


Assuntos
Bactérias , Peixes , Armazenamento de Alimentos , Congelamento , Microbiota , RNA Ribossômico 16S , Alimentos Marinhos , Compostos Orgânicos Voláteis , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo , Peixes/microbiologia , Brasil , Alimentos Marinhos/microbiologia , Alimentos Marinhos/análise , RNA Ribossômico 16S/genética , Gelo , Microbiologia de Alimentos , Biodiversidade , Feminino
17.
J Exp Biol ; 227(17)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39221648

RESUMO

Higher temperatures exacerbate drought conditions by increasing evaporation rates, reducing soil moisture and altering precipitation patterns. As global temperatures rise as a result of climate change, these effects intensify, leading to more frequent and severe droughts. This link between higher temperatures and drought is particularly evident in sensitive ecosystems like the Amazon rainforest, where reduced rainfall and higher evaporation rates result in significantly lower water levels, threatening biodiversity and human livelihoods. As an example, the serious drought experienced in the Amazon basin in 2023 resulted in a significant decline in fish populations. Elevated water temperatures, reaching up to 38°C, led to mass mortality events, because these temperatures surpass the thermal tolerance of many Amazonian fish species. We know this because our group has collected data on critical thermal maxima (CTmax) for various fish species over multiple years. Additionally, warmer waters can cause hypoxia, further exacerbating fish mortality. Thus, even Amazon fish species, which have relatively high thermal tolerance, are being impacted by climate change. The Amazon drought experienced in 2023 underscores the urgent need for climate action to mitigate the devastating effects on Amazonian biodiversity. The fact that we have been able to link fish mortality events to data on the thermal tolerance of fishes emphasizes the important role of experimental biology in elucidating the mechanisms behind these events, a link that we aim to highlight in this Perspective.


Assuntos
Mudança Climática , Secas , Peixes , Animais , Biodiversidade , Brasil , Peixes/fisiologia , Floresta Úmida
18.
Nature ; 634(8032): 96-103, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39143221

RESUMO

The genomes of living lungfishes can inform on the molecular-developmental basis of the Devonian sarcopterygian fish-tetrapod transition. We de novo sequenced the genomes of the African (Protopterus annectens) and South American lungfishes (Lepidosiren paradoxa). The Lepidosiren genome (about 91 Gb, roughly 30 times the human genome) is the largest animal genome sequenced so far and more than twice the size of the Australian (Neoceratodus forsteri)1 and African2 lungfishes owing to enlarged intergenic regions and introns with high repeat content (about 90%). All lungfish genomes continue to expand as some transposable elements (TEs) are still active today. In particular, Lepidosiren's genome grew extremely fast during the past 100 million years (Myr), adding the equivalent of one human genome every 10 Myr. This massive genome expansion seems to be related to a reduction of PIWI-interacting RNAs and C2H2 zinc-finger and Krüppel-associated box (KRAB)-domain protein genes that suppress TE expansions. Although TE abundance facilitates chromosomal rearrangements, lungfish chromosomes still conservatively reflect the ur-tetrapod karyotype. Neoceratodus' limb-like fins still resemble those of their extinct relatives and remained phenotypically static for about 100 Myr. We show that the secondary loss of limb-like appendages in the Lepidosiren-Protopterus ancestor was probably due to loss of sonic hedgehog limb-specific enhancers.


Assuntos
Evolução Molecular , Peixes , Genoma , Animais , Humanos , África , Nadadeiras de Animais/anatomia & histologia , Austrália , Elementos de DNA Transponíveis/genética , DNA Intergênico/genética , Elementos Facilitadores Genéticos/genética , Extinção Biológica , Peixes/anatomia & histologia , Peixes/classificação , Peixes/genética , Rearranjo Gênico/genética , Genoma/genética , Tamanho do Genoma , Proteínas Hedgehog/genética , Íntrons , Cariótipo , Filogenia , RNA de Interação com Piwi/genética , América do Sul , Fatores de Tempo , Dedos de Zinco/genética
19.
J Fish Biol ; 105(4): 1357-1361, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39109773

RESUMO

Sciadonus alphacrucis Melo, Gomes, Møller & Nielsen, 2022 is a rare deep-sea species, previously known from only two specimens collected off São Paulo State, southeastern Brazil, in the western South Atlantic. Herein, we report a new specimen of S. alphacrucis collected on the continental slope off Santa Catarina State, southern Brazil, thereby extending its known distribution by 420 km. Additionally, we provide the new meristic and morphometric data, the molecular identification using sequences of the cytochrome c oxidase subunit I (COI), an updated distribution map, and a discussion of troglomorphic traits.


Assuntos
Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons , Animais , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Oceano Atlântico , Filogenia , Distribuição Animal , Feminino , Masculino , Peixes/genética , Peixes/classificação
20.
Food Addit Contam Part B Surveill ; 17(4): 319-327, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39105309

RESUMO

Organochlorine, organophosphate, triazole, and strobilurin pesticides were determined in fish samples. Relative standard deviations lower than 9.3% were obtained for organochlorine pesticides and 10.8% for other pesticides. Accuracy ranged from 73% to 119% for organochlorine pesticides and 80.4% to 116% for organophosphate, triazole, and strobilurin pesticides. A total of 28 pesticides were analysed and 7 of them were detected (exceeding 10 µg/kg) in some samples, with the highest concentration recorded at 68.5 µg/kg, corresponding to heptachlor epoxide A. The pesticide most frequently detected was ß HCH, found in 30 of the 100 analysed samples. Hazard Quotient values were estimated for men, women, and children. These values exceeded 1 for heptachlor epoxide in women and children, as well as for endrin in children. These findings emphasise the need for stricter controls to reduce fish contamination and mitigate health risks.


Assuntos
Peixes , Contaminação de Alimentos , Resíduos de Praguicidas , Rios , Animais , Medição de Risco , Humanos , Contaminação de Alimentos/análise , Argentina , Rios/química , Resíduos de Praguicidas/análise , Feminino , Praguicidas/análise , Poluentes Químicos da Água/análise , Criança , Masculino , Adulto , Hidrocarbonetos Clorados/análise , Alimentos Marinhos/análise
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