Pub Date : 2023-07-10DOI: 10.1590/1982-0224-2023-0022
L. Gomes, R. M. Dias, Renata Ruaro, E. Benedito
Abstract Functional diversity is an emergent approach in ecology that has been applied globally to better understand the relationships between organisms and the environment. However, assessing the functional diversity of freshwater fish is a challenge for scientists. Aiming to summarize the evolution of scientific knowledge on fish functional diversity, we performed a systematic review of the literature published from 1945 to 2021 using the Web of Science. Based on the 101 articles reviewed, we found that publications about functional diversity of fishes have increased over time, mainly in Neotropical, Indomalayan and Palearctic regions. Most studies were conducted in lotic ecosystems, especially to assess environmental impacts such as biological invasions and land use. Functional diversity has been assessed mainly by morphological traits that reflect feeding and locomotion dimensions. Functional richness was the most common index used in the studies. Our findings suggest that political neglect and lack of investments may hamper the research development in several places. The missing information about the functional traits of many species may limit the use of the functional approach. We also highlight the need for the incorporation of functional diversity in conservation programs once functional diversity is a key facet of biodiversity to maintain freshwater ecosystem functioning.
功能多样性是一种新兴的生态学方法，已在全球范围内得到应用，以更好地理解生物与环境之间的关系。然而，评估淡水鱼的功能多样性对科学家来说是一个挑战。为了总结关于鱼类功能多样性的科学知识的演变，我们使用Web of Science对1945年至2021年发表的文献进行了系统的回顾。通过对101篇论文的回顾，我们发现，随着时间的推移，有关鱼类功能多样性的论文有所增加，主要集中在新热带、印多马拉雅和古北纬地区。大多数研究是在地理生态系统中进行的，特别是评估生物入侵和土地利用等环境影响。功能多样性主要通过反映摄食和运动维度的形态特征来评估。功能丰富度是研究中最常用的指标。我们的研究结果表明，政治上的忽视和缺乏投资可能会阻碍一些地方的研究发展。许多物种的功能性状信息的缺失可能会限制功能方法的使用。我们还强调，一旦功能多样性成为维持淡水生态系统功能的生物多样性的关键方面，就需要将功能多样性纳入保护计划。
{"title":"Functional diversity: a review on freshwater fish research","authors":"L. Gomes, R. M. Dias, Renata Ruaro, E. Benedito","doi":"10.1590/1982-0224-2023-0022","DOIUrl":"https://doi.org/10.1590/1982-0224-2023-0022","url":null,"abstract":"Abstract Functional diversity is an emergent approach in ecology that has been applied globally to better understand the relationships between organisms and the environment. However, assessing the functional diversity of freshwater fish is a challenge for scientists. Aiming to summarize the evolution of scientific knowledge on fish functional diversity, we performed a systematic review of the literature published from 1945 to 2021 using the Web of Science. Based on the 101 articles reviewed, we found that publications about functional diversity of fishes have increased over time, mainly in Neotropical, Indomalayan and Palearctic regions. Most studies were conducted in lotic ecosystems, especially to assess environmental impacts such as biological invasions and land use. Functional diversity has been assessed mainly by morphological traits that reflect feeding and locomotion dimensions. Functional richness was the most common index used in the studies. Our findings suggest that political neglect and lack of investments may hamper the research development in several places. The missing information about the functional traits of many species may limit the use of the functional approach. We also highlight the need for the incorporation of functional diversity in conservation programs once functional diversity is a key facet of biodiversity to maintain freshwater ecosystem functioning.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-10DOI: 10.1590/1982-0224-2023-0030
Mariana Landucci Giongo, M. L. Petesse, K. E. Esteves
Abstract Environmental factors act at multiple spatial scales in a hierarchical manner to shape the organization of biota. However, the relative influence of different scale-related factors is poorly known, especially in Atlantic Forest Blackwater streams. Therefore, we herein aimed to evaluate local, landscape and spatial factors that shape fish assemblages in 14 blackwater restinga coastal Atlantic Forest streams under natural conditions and verify species occurrence patterns among four sub-basins during the low-precipitation season. When we combined local, landscape and spatial factors, variance partitioning explained a high proportion of variation in species matrix. Local variables pH and Total Dissolved Solids explained most of the variability, and these were the most important factors in determining fish community structure. Significant differences in fish assemblage structure among the four sub-basins were observed, and Mimagoniates microlepis, Phalloceros harpagos, and Hollandichthys multifasciatus were the species that most contributed to this dissimilarity. The important contribution of local predictors, the high number of endemic species herein recorded, the presence of an endangered species (Spintherobolus broccae), and near pristine conditions, may be used as baseline conditions for the assessment of similar environments.
{"title":"Fish responses to multiple scales in coastal blackwater Atlantic Forest streams in Southeast Brazil","authors":"Mariana Landucci Giongo, M. L. Petesse, K. E. Esteves","doi":"10.1590/1982-0224-2023-0030","DOIUrl":"https://doi.org/10.1590/1982-0224-2023-0030","url":null,"abstract":"Abstract Environmental factors act at multiple spatial scales in a hierarchical manner to shape the organization of biota. However, the relative influence of different scale-related factors is poorly known, especially in Atlantic Forest Blackwater streams. Therefore, we herein aimed to evaluate local, landscape and spatial factors that shape fish assemblages in 14 blackwater restinga coastal Atlantic Forest streams under natural conditions and verify species occurrence patterns among four sub-basins during the low-precipitation season. When we combined local, landscape and spatial factors, variance partitioning explained a high proportion of variation in species matrix. Local variables pH and Total Dissolved Solids explained most of the variability, and these were the most important factors in determining fish community structure. Significant differences in fish assemblage structure among the four sub-basins were observed, and Mimagoniates microlepis, Phalloceros harpagos, and Hollandichthys multifasciatus were the species that most contributed to this dissimilarity. The important contribution of local predictors, the high number of endemic species herein recorded, the presence of an endangered species (Spintherobolus broccae), and near pristine conditions, may be used as baseline conditions for the assessment of similar environments.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-23DOI: 10.1590/1982-0224-2023-0027
Karla D. A. Soares, F. F. Petean
Abstract
摘要
{"title":"Three decades of Chondrichthyan research in Brazil assessed from conferences’ abstracts: patterns, gaps, and expectations","authors":"Karla D. A. Soares, F. F. Petean","doi":"10.1590/1982-0224-2023-0027","DOIUrl":"https://doi.org/10.1590/1982-0224-2023-0027","url":null,"abstract":"Abstract","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-23DOI: 10.1590/1982-0224-2023-0005
Waslley Maciel Pinheiro, J. Santander-Neto, Isabelle D. B. Arthaud, V. V. Faria
Abstract Sharks are among the marine organisms most impacted by intense fisheries, a worrying fact since they are key components in the trophic structure of ecosystems. In this context, fish landing data can help managers in shark conservation. This study characterized the landings of Carcharhinus acronotus, Mustelus cf. canis, and Sphyrna mokarran in the Mucuripe Embayment, Ceará, Brazil, along three study periods (1998–1999, 2006–2008, and 2015–2016). A total of 223 specimens were recorded from 227 site visits. Carcharhinus acronotus specimens measured from 50 to 139 cm in total length (TL), with a 1.3:1 sex ratio in favor of males. Most of the specimens recorded were adults (55.1% of males and 62.9% of females). Mustelus cf. canis varied from 64 to 133 cm in TL, with a sex ratio in favor of females (3.1:1). Most of the specimens recorded were adults (50% of males and 68% of females). Sphyrna mokarran specimens varied from 116 to 380 cm in TL, with a sex ratio of 7:1 in favor of males. Most of the specimens recorded were juveniles. This is the first fishery-dependent study to provide information on size and sex composition of these species for most of the southwestern equatorial Atlantic.
{"title":"Size and sex composition of three carcharhiniform sharks landed by a coastal artisanal fleet from the northeastern coast of Brazil","authors":"Waslley Maciel Pinheiro, J. Santander-Neto, Isabelle D. B. Arthaud, V. V. Faria","doi":"10.1590/1982-0224-2023-0005","DOIUrl":"https://doi.org/10.1590/1982-0224-2023-0005","url":null,"abstract":"Abstract Sharks are among the marine organisms most impacted by intense fisheries, a worrying fact since they are key components in the trophic structure of ecosystems. In this context, fish landing data can help managers in shark conservation. This study characterized the landings of Carcharhinus acronotus, Mustelus cf. canis, and Sphyrna mokarran in the Mucuripe Embayment, Ceará, Brazil, along three study periods (1998–1999, 2006–2008, and 2015–2016). A total of 223 specimens were recorded from 227 site visits. Carcharhinus acronotus specimens measured from 50 to 139 cm in total length (TL), with a 1.3:1 sex ratio in favor of males. Most of the specimens recorded were adults (55.1% of males and 62.9% of females). Mustelus cf. canis varied from 64 to 133 cm in TL, with a sex ratio in favor of females (3.1:1). Most of the specimens recorded were adults (50% of males and 68% of females). Sphyrna mokarran specimens varied from 116 to 380 cm in TL, with a sex ratio of 7:1 in favor of males. Most of the specimens recorded were juveniles. This is the first fishery-dependent study to provide information on size and sex composition of these species for most of the southwestern equatorial Atlantic.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-23DOI: 10.1590/1982-0224-2022-0084
Vida Souza, Leonardo Oliveira-Silva, Rayana Tiago Dutra, P. Camelier
Abstract The Northeastern Mata Atlântica freshwater ecoregion (NMAF) is recognized for the high degree of endemism of its ichthyofauna, whose evolutionary and biogeographic histories are still poorly understood. Oligosarcus acutirostris is a freshwater fish species endemic to the NMAF, which is distributed in coastal rivers and streams draining Bahia, Espírito Santo, and part of Minas Gerais states in eastern Brazil. Its widespread distribution in currently isolated river basins along the NMAF prompted this study, which aimed to understand what scenarios would be involved in determining its current distribution pattern, and to contribute to a better understanding of the biogeographic history of the NMAF. For this, mitochondrial and nuclear DNA sequences were analyzed based on samples from different localities along the species distribution, including its type locality. Overall, phylogeographic analyses indicate a strong genetic structure within the species evidenced mainly by the non-sharing of haplotypes between most of the basins analyzed. According to the AMOVA results, the current distribution of haplotypes is better explained by the Pleistocene coastal paleodrainages. The results are also used to test and complement a biogeographic hypothesis previously proposed for the drainages of the NMAF.
{"title":"Phylogeography of Oligosarcus acutirostris (Characiformes: Characidae): testing biogeographic hypotheses in the Northeastern Mata Atlântica freshwater ecoregion","authors":"Vida Souza, Leonardo Oliveira-Silva, Rayana Tiago Dutra, P. Camelier","doi":"10.1590/1982-0224-2022-0084","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0084","url":null,"abstract":"Abstract The Northeastern Mata Atlântica freshwater ecoregion (NMAF) is recognized for the high degree of endemism of its ichthyofauna, whose evolutionary and biogeographic histories are still poorly understood. Oligosarcus acutirostris is a freshwater fish species endemic to the NMAF, which is distributed in coastal rivers and streams draining Bahia, Espírito Santo, and part of Minas Gerais states in eastern Brazil. Its widespread distribution in currently isolated river basins along the NMAF prompted this study, which aimed to understand what scenarios would be involved in determining its current distribution pattern, and to contribute to a better understanding of the biogeographic history of the NMAF. For this, mitochondrial and nuclear DNA sequences were analyzed based on samples from different localities along the species distribution, including its type locality. Overall, phylogeographic analyses indicate a strong genetic structure within the species evidenced mainly by the non-sharing of haplotypes between most of the basins analyzed. According to the AMOVA results, the current distribution of haplotypes is better explained by the Pleistocene coastal paleodrainages. The results are also used to test and complement a biogeographic hypothesis previously proposed for the drainages of the NMAF.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-23DOI: 10.1590/1982-0224-2022-0107
Í. S. Castro, W. B. Wosiacki
Abstract Phenacorhamdia nigrolineata is redescribed, and the expansion of its geographic distribution is presented based on abundant new records. Morphological analysis, meristic comparison and osteological description were performed. No one autapomorphy was identified for P. nigrolineata, but the species is identified by an exclusive combination of characters of coloration of the body, morphometric and meristic data (snout length, maxillary and outer mental barbels length; number of vertebrae). A discussion of its geographic distribution, coloration pattern of the body, the putative relationships among some species of the genus, and its conservation status are presented.
{"title":"Redescription and expansion of the geographic distribution of Phenacorhamdia nigrolineata (Siluriformes: Heptapteridae)","authors":"Í. S. Castro, W. B. Wosiacki","doi":"10.1590/1982-0224-2022-0107","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0107","url":null,"abstract":"Abstract Phenacorhamdia nigrolineata is redescribed, and the expansion of its geographic distribution is presented based on abundant new records. Morphological analysis, meristic comparison and osteological description were performed. No one autapomorphy was identified for P. nigrolineata, but the species is identified by an exclusive combination of characters of coloration of the body, morphometric and meristic data (snout length, maxillary and outer mental barbels length; number of vertebrae). A discussion of its geographic distribution, coloration pattern of the body, the putative relationships among some species of the genus, and its conservation status are presented.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-29DOI: 10.1590/1982-0224-2022-0072
Cristhian Danilo Joya, Ana María Ochoa-Aristizábal, José Gregorio Martínez, E. Márquez
Abstract Pimelodus grosskopfii and Pimelodus yuma, two species endemic to the Magdalena-Cauca basin in Colombia, overlap in the ranges of some of their diagnostic characters, which hampers their correct morphological identification. Aiming to help discriminate these species, this study conducted an integrative analysis using traditional and geometric morphometrics, phylogenetic analysis based on partial sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (COI, cox1) and the identification of diagnostic Single Nucleotide Polymorphism markers (SNP). The species differ significantly in body geometry, allowing 100% discrimination, which was reinforced by a phylogenetic analysis that recovered well-supported monophyly of each species (posterior probability > 0.95). Additionally, the traditional morphometric results corroborated some previously reported diagnostic traits for both species and let us describe one non-overlapping ratio related to the adipose fin length. Three of five SNP markers had reciprocally exclusive alleles suitable for identifying each species. The morphometric and molecular methods conducted in this study constitute alternative tools for the correct discrimination of P. grosskopfii and P. yuma in the wild and in captive populations used for aquaculture.
{"title":"Morphometric and molecular differentiation of Pimelodus grosskopfii and Pimelodus yuma (Siluriformes: Pimelodidae)","authors":"Cristhian Danilo Joya, Ana María Ochoa-Aristizábal, José Gregorio Martínez, E. Márquez","doi":"10.1590/1982-0224-2022-0072","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0072","url":null,"abstract":"Abstract Pimelodus grosskopfii and Pimelodus yuma, two species endemic to the Magdalena-Cauca basin in Colombia, overlap in the ranges of some of their diagnostic characters, which hampers their correct morphological identification. Aiming to help discriminate these species, this study conducted an integrative analysis using traditional and geometric morphometrics, phylogenetic analysis based on partial sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (COI, cox1) and the identification of diagnostic Single Nucleotide Polymorphism markers (SNP). The species differ significantly in body geometry, allowing 100% discrimination, which was reinforced by a phylogenetic analysis that recovered well-supported monophyly of each species (posterior probability > 0.95). Additionally, the traditional morphometric results corroborated some previously reported diagnostic traits for both species and let us describe one non-overlapping ratio related to the adipose fin length. Three of five SNP markers had reciprocally exclusive alleles suitable for identifying each species. The morphometric and molecular methods conducted in this study constitute alternative tools for the correct discrimination of P. grosskopfii and P. yuma in the wild and in captive populations used for aquaculture.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-22DOI: 10.1590/1982-0224-2022-0068
Clara V. Teixeira-Leite, M. Vianna
Abstract Biodiversity baselines are essential subsidies to evaluate how environmental changes and human impacts affect the special and temporal patterns of communities. This information is paramount to promote proper conservation and management for historically impacted environments such as Guanabara Bay, in southeastern Brazil. Here, we propose an ichthyofaunal baseline for this bay using gathered past data from 1889 to 2020, including literature records, scientific collections, biological sampling, and fisheries landing monitoring. A total of 220 species (203 teleosts and 17 elasmobranchs), distributed in 149 genera (136 teleosts and 13 elasmobranchs) and 72 families (61 teleosts and 11 elasmobranchs) were recorded, including the first record of a tiger-shark, Galeocerdo cuvier, in Guanabara Bay. Although the employed sampling effort was sufficient to represent the ichthyofauna in the middle and upper estuary, the Chao2 estimator indicates an even greater richness regarding the bay as a whole. Evidence of reduced abundance and probable local extinction over the decades was found, supporting the importance of implementing management and conservation strategies in the area. The ichthyofaunal distribution analyses revealed that areas close to conservation units are richer compared to their surroundings, indicating that this is an effective strategy to mitigate human impacts in the bay.
{"title":"Building a baseline: a survey of the composition and distribution of the ichthyofauna of Guanabara Bay, a deeply impacted estuary","authors":"Clara V. Teixeira-Leite, M. Vianna","doi":"10.1590/1982-0224-2022-0068","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0068","url":null,"abstract":"Abstract Biodiversity baselines are essential subsidies to evaluate how environmental changes and human impacts affect the special and temporal patterns of communities. This information is paramount to promote proper conservation and management for historically impacted environments such as Guanabara Bay, in southeastern Brazil. Here, we propose an ichthyofaunal baseline for this bay using gathered past data from 1889 to 2020, including literature records, scientific collections, biological sampling, and fisheries landing monitoring. A total of 220 species (203 teleosts and 17 elasmobranchs), distributed in 149 genera (136 teleosts and 13 elasmobranchs) and 72 families (61 teleosts and 11 elasmobranchs) were recorded, including the first record of a tiger-shark, Galeocerdo cuvier, in Guanabara Bay. Although the employed sampling effort was sufficient to represent the ichthyofauna in the middle and upper estuary, the Chao2 estimator indicates an even greater richness regarding the bay as a whole. Evidence of reduced abundance and probable local extinction over the decades was found, supporting the importance of implementing management and conservation strategies in the area. The ichthyofaunal distribution analyses revealed that areas close to conservation units are richer compared to their surroundings, indicating that this is an effective strategy to mitigate human impacts in the bay.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-22DOI: 10.1590/1982-0224-2022-0098
Santiago Larre-Campuzano, H. Espinosa-Pérez, N. Mercado-Silva, Néstor Rosales-Quintero, Wilfredo A. Matamoros
Abstract Understanding patterns of freshwater fish assemblage structure is key to protect them from ongoing human-induced threats to aquatic biodiversity. Yet, studies on associations between fish assemblages and habitat are lacking from many areas of high diversity in Middle America. We assessed fish assemblage structure and environmental associations from a portion of the Lacantún River sub-basin (Usumacinta River, Chiapas, Mexico). Based on environmental data and 17,462 individuals (56 species, 46 genera, and 22 families) captured from 13 sites sampled between 2017–2019, we found that stream order, distance to the Usumacinta, forest cover, temperature, and dissolved oxygen are key to explaining assemblage composition. Four clusters were found via multivariate regression tree analysis, with stream order and dissolved oxygen as defining variables. Our findings suggest that fish communities remain spatially structured even at small scales, in association to environmental gradients among habitats.
{"title":"Variation in patterns of fish assemblage and their environmental correlates in a tropical river basin from the Gulf of Mexico slope","authors":"Santiago Larre-Campuzano, H. Espinosa-Pérez, N. Mercado-Silva, Néstor Rosales-Quintero, Wilfredo A. Matamoros","doi":"10.1590/1982-0224-2022-0098","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0098","url":null,"abstract":"Abstract Understanding patterns of freshwater fish assemblage structure is key to protect them from ongoing human-induced threats to aquatic biodiversity. Yet, studies on associations between fish assemblages and habitat are lacking from many areas of high diversity in Middle America. We assessed fish assemblage structure and environmental associations from a portion of the Lacantún River sub-basin (Usumacinta River, Chiapas, Mexico). Based on environmental data and 17,462 individuals (56 species, 46 genera, and 22 families) captured from 13 sites sampled between 2017–2019, we found that stream order, distance to the Usumacinta, forest cover, temperature, and dissolved oxygen are key to explaining assemblage composition. Four clusters were found via multivariate regression tree analysis, with stream order and dissolved oxygen as defining variables. Our findings suggest that fish communities remain spatially structured even at small scales, in association to environmental gradients among habitats.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-12DOI: 10.1590/1982-0224-2023-0032
Rosane Silva-Santos, C. Machado, A. Zanata, P. Camelier, P. M. Galetti Jr., P. D. Freitas
Abstract Molecular tools have been employed to improve the knowledge about freshwater Neotropical fishes. Such approaches supporting studies of groups including species complexes such as Astyanax, one of the most diversified and taxonomically complex genus of the family Characidae. Here, we employed species delimitation analyses in four Astyanax species described for the upper Paraguaçu River basin, a drainage within Northeastern Mata Atlântica freshwater ecoregion with high endemism. We implemented single and multilocus approaches based on two mitochondrial and one nuclear markers. Cytochrome c Oxidase I sequences previously available for Astyanax species were also added to our dataset. The single locus analyses showed A. epiagos, A. rupestris, and A. aff. rupestris as different Molecular Operational Taxonomic Units (MOTUs), while A. brucutu and A. lorien were grouped. However, the multilocus approach distinguished these two species and showed congruence for the remaining single locus results. Astyanax aff. rupestris was separated into two MOTUs using both approaches, highlighting the need for an integrative taxonomic revision including A. aff. rupestris. These findings contribute to a better understanding of the diversity of this fish group in the upper Paraguaçu, identifying hidden diversity and reinforcing the relevance of this hydrographic system as a notable hotspot for ichthyofauna biodiversity endemism.
分子工具已被用于提高对淡水新热带鱼类的认识。这些方法支持对包括物种复合体在内的类群的研究，如Astyanax，它是家蚕科中最多样化和分类学最复杂的属之一。本文对巴拉圭河上游流域的4种Astyanax进行了物种划分分析。巴拉圭河上游流域是Mata atlntica东北部的一个高地方性淡水生态区。我们实施了基于两个线粒体和一个核标记的单位点和多位点方法。先前可用的Astyanax物种的细胞色素c氧化酶I序列也被添加到我们的数据集中。单基因座分析表明，长尾拟南毛猴、鲁氏拟南毛猴和鲁氏拟南毛猴为不同的分子操作分类单元(MOTUs)，而布鲁库拟南毛猴和洛林拟南毛猴为同一组。然而，多位点方法区分了这两个物种，并显示了其余单位点结果的一致性。利用这两种方法将Astyanax af . rupestris分离为两个MOTUs，表明需要对包括A. af . rupestris在内的Astyanax af . rupestris进行综合分类修订。这些发现有助于更好地了解巴拉圭河上游这一鱼类群体的多样性，识别隐藏的多样性，并加强该水文系统作为鱼系生物多样性地方性研究的重要热点的相关性。
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