Pub Date : 2022-01-01DOI: 10.1590/1982-0224-2021-0141
Aymar Orlandi-Neto, R. V. Amorim, R. L. Delariva, A. F. Camargo, R. Veríssimo‐Silveira, I. P. Ramos
Abstract In 2014, an atypical drought in Southeast Brazil drastically reduced the water level in several reservoirs. We investigated the effects of this drought and the subsequent flood period on the attributes of ichthyofauna in an aquaculture and in a control area. Fish were collected bimonthly between 2014 and 2015 (drought) and 2016 (wet), using gill nets in the two sample areas in the Ilha Solteira reservoir, Upper Paraná River basin, Brazil. We compared ichthyofauna attributes between the drought and wet seasons in each area and between areas within each season. In the aquaculture area, the assemblages showed similar characteristics between the seasons. By contrast, the control area varied between seasons, with greater species richness, Shannon diversity, species evenness, and less β diversity in the wet season. Comparisons between areas in each season showed higher abundance in the fish farm within the drought season. Changes in structure and composition in the control area are possibly associated with new areas and resources made available by the flooding of marginal areas during the wet season. We inferred that the effect of the flood on the aquaculture community was attenuated by the continuous habitat structure such as shelters and food provided by the enterprise.
{"title":"Structure and composition of ichthyofauna associated with cage fish farming and compared to a control area after severe drought in a Neotropical reservoir","authors":"Aymar Orlandi-Neto, R. V. Amorim, R. L. Delariva, A. F. Camargo, R. Veríssimo‐Silveira, I. P. Ramos","doi":"10.1590/1982-0224-2021-0141","DOIUrl":"https://doi.org/10.1590/1982-0224-2021-0141","url":null,"abstract":"Abstract In 2014, an atypical drought in Southeast Brazil drastically reduced the water level in several reservoirs. We investigated the effects of this drought and the subsequent flood period on the attributes of ichthyofauna in an aquaculture and in a control area. Fish were collected bimonthly between 2014 and 2015 (drought) and 2016 (wet), using gill nets in the two sample areas in the Ilha Solteira reservoir, Upper Paraná River basin, Brazil. We compared ichthyofauna attributes between the drought and wet seasons in each area and between areas within each season. In the aquaculture area, the assemblages showed similar characteristics between the seasons. By contrast, the control area varied between seasons, with greater species richness, Shannon diversity, species evenness, and less β diversity in the wet season. Comparisons between areas in each season showed higher abundance in the fish farm within the drought season. Changes in structure and composition in the control area are possibly associated with new areas and resources made available by the flooding of marginal areas during the wet season. We inferred that the effect of the flood on the aquaculture community was attenuated by the continuous habitat structure such as shelters and food provided by the enterprise.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200132","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 : 2022-01-01DOI: 10.1590/1982-0224-2022-0039
Geovana de Souza Andrade, F. Pelicice
Abstract Peacock basses (genus Cichla) are predatory fish widely distributed across the Amazon, where two or more species normally coexist in a same drainage. The mechanisms that allow coexistence remain poorly understood, although these species share a number of functional traits and behavioral aspects. To advance on this question, the present study compared population and functional traits of Cichla kelberi and C. piquiti, based on data collected between 2010 and 2020 in the upper section of the Lajeado Reservoir, Tocantins River. Both species were captured in all sampling sites, frequently in a same sample, but C. piquiti was far more frequent and abundant. The species used the same habitats, and co-occurred more often than expected by chance. Species had a similar diet (small-sized fish), reproductive effort, fecundity and fat accumulation, but C. piquiti showed larger body sizes, shoaling behavior, a longer reproductive period, and morphology associated with greater swimming potential. Overall, results revealed that these species coexist in the impoundment, with significant overlap in the use of habitats and food resources. Differences in other functional traits may favor their coexistence, possibly involving niche partitioning, which seem to explain the dominance of C. piquiti in the impoundment.
{"title":"Coexistence of endemic peacock basses (Cichla) in a Neotropical reservoir (Cichlidae: Cichliformes)","authors":"Geovana de Souza Andrade, F. Pelicice","doi":"10.1590/1982-0224-2022-0039","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0039","url":null,"abstract":"Abstract Peacock basses (genus Cichla) are predatory fish widely distributed across the Amazon, where two or more species normally coexist in a same drainage. The mechanisms that allow coexistence remain poorly understood, although these species share a number of functional traits and behavioral aspects. To advance on this question, the present study compared population and functional traits of Cichla kelberi and C. piquiti, based on data collected between 2010 and 2020 in the upper section of the Lajeado Reservoir, Tocantins River. Both species were captured in all sampling sites, frequently in a same sample, but C. piquiti was far more frequent and abundant. The species used the same habitats, and co-occurred more often than expected by chance. Species had a similar diet (small-sized fish), reproductive effort, fecundity and fat accumulation, but C. piquiti showed larger body sizes, shoaling behavior, a longer reproductive period, and morphology associated with greater swimming potential. Overall, results revealed that these species coexist in the impoundment, with significant overlap in the use of habitats and food resources. Differences in other functional traits may favor their coexistence, possibly involving niche partitioning, which seem to explain the dominance of C. piquiti in the impoundment.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200189","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 : 2022-01-01DOI: 10.1590/1982-0224-2021-0126
S. Y. Lustosa-Costa, T. Ramos, C. H. Zawadzki, S. Lima
Abstract The species of Hypostomus from the Parnaíba River basin were reviewed through molecular and morphological analysis. Five species were found in the basin, including a new species herein described. The distribution of H. pusarum was expanded to this basin, and a closely related species was recorded (H. aff. pusarum), also the presence of H. johnii and H. vaillanti was confirmed. The new species is distinguished from most congeners by its large number of premaxillary and dentary teeth, a wide dental angle of 115° to 135°, presence of a rounded dark spots on a lighter background and anteromedial region of the abdomen depleted of plaques (vs. anteromedial region of the abdomen covered by platelets and odontodes in H. johnii, H. pusarum, H. aff. pusarum and H. vaillanti). Furthermore, an identification key of the species from the Maranhão-Piauí ecoregion and maps with the geographic distribution of these species are presented. The species of Hypostomus in the Parnaíba River basin have different geographic distributions, suggesting different niches or geographical barriers, providing an opportunity for ecological and evolutionary studies.
摘要通过分子和形态分析，对Parnaíba河流域的下stomus属植物进行了综述。在盆地中发现了5种，其中包括本文描述的一种新种。将pusarum的分布范围扩大到该盆地，并记录到一个近缘种(h.a ff. pusarum)，同时确认了H. johnii和H. vaillanti的存在。该新种与大多数同系种的区别在于其大量的上颌前牙和牙列牙，牙角宽为115°至135°，背景较浅，腹部前内侧区域没有斑块(相比之下，H. johnii, H. pusarum, H. afft . pusarum和H. vaillanti的腹部前内侧区域被血小板和齿状体覆盖)。此外，还给出了Maranhão-Piauí生态区的物种识别键和物种地理分布图。Parnaíba河流域的低stomus物种具有不同的地理分布，提示不同的生态位或地理屏障，为生态学和进化研究提供了机会。
{"title":"Review of the armoured catfish genus Hypostomus (Siluriformes: Loricariidae) from the Parnaíba River basin, Northeastern Brazil, with description of a new species","authors":"S. Y. Lustosa-Costa, T. Ramos, C. H. Zawadzki, S. Lima","doi":"10.1590/1982-0224-2021-0126","DOIUrl":"https://doi.org/10.1590/1982-0224-2021-0126","url":null,"abstract":"Abstract The species of Hypostomus from the Parnaíba River basin were reviewed through molecular and morphological analysis. Five species were found in the basin, including a new species herein described. The distribution of H. pusarum was expanded to this basin, and a closely related species was recorded (H. aff. pusarum), also the presence of H. johnii and H. vaillanti was confirmed. The new species is distinguished from most congeners by its large number of premaxillary and dentary teeth, a wide dental angle of 115° to 135°, presence of a rounded dark spots on a lighter background and anteromedial region of the abdomen depleted of plaques (vs. anteromedial region of the abdomen covered by platelets and odontodes in H. johnii, H. pusarum, H. aff. pusarum and H. vaillanti). Furthermore, an identification key of the species from the Maranhão-Piauí ecoregion and maps with the geographic distribution of these species are presented. The species of Hypostomus in the Parnaíba River basin have different geographic distributions, suggesting different niches or geographical barriers, providing an opportunity for ecological and evolutionary studies.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199498","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 : 2022-01-01DOI: 10.1590/1982-0224-2021-0127
F. P. Dagosta, M. Marinho
Abstract A new species of Astyanax is described from the rio Salobra, tributary of rio Cuiabá, rio Paraguai basin. The new taxon can be distinguished from its congeners by having a well-defined dark midlateral stripe on body extending from the posterior margin of the opercle to the base of middle caudal-fin rays and a single vertical elongate humeral blotch. Although the new species is described in Astyanax, some specimens present an incomplete or a discontinuous series of perforated scales in the lateral line. Therefore, a discussion on its generic allocation is presented. Comments on different patterns of coloration among dark-striped species of Astyanax are also provided. The discovery of a new species in an underwater tourist point relatively near a large urban center underscores that even fish species daily observed by hundreds of people in limpid waters may lack a formal taxonomic identity. Such finding also highlights how the megadiverse Brazilian freshwater ichthyofauna still needs efforts and investments to identify and describe new taxa.
{"title":"New small-sized species of Astyanax (Characiformes: Characidae) from the upper rio Paraguai basin, Brazil, with discussion on its generic allocation","authors":"F. P. Dagosta, M. Marinho","doi":"10.1590/1982-0224-2021-0127","DOIUrl":"https://doi.org/10.1590/1982-0224-2021-0127","url":null,"abstract":"Abstract A new species of Astyanax is described from the rio Salobra, tributary of rio Cuiabá, rio Paraguai basin. The new taxon can be distinguished from its congeners by having a well-defined dark midlateral stripe on body extending from the posterior margin of the opercle to the base of middle caudal-fin rays and a single vertical elongate humeral blotch. Although the new species is described in Astyanax, some specimens present an incomplete or a discontinuous series of perforated scales in the lateral line. Therefore, a discussion on its generic allocation is presented. Comments on different patterns of coloration among dark-striped species of Astyanax are also provided. The discovery of a new species in an underwater tourist point relatively near a large urban center underscores that even fish species daily observed by hundreds of people in limpid waters may lack a formal taxonomic identity. Such finding also highlights how the megadiverse Brazilian freshwater ichthyofauna still needs efforts and investments to identify and describe new taxa.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199544","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 : 2022-01-01DOI: 10.1590/1982-0224-2022-0046
R. M. Dias, Oscar Peláez, T. M. Lopes, A. G. Oliveira, M. A. Angulo-Valencia, A. Agostinho
Abstract In the upper Paraná River floodplain, the populations of Salminus brasiliensis have been subjected to several anthropic impacts, such as overfishing, the blocking of migratory routes by dams, and regulation of the flood regime. Its populations have disappeared or become depleted in most rivers in this basin. These populations are the target of protection measures aimed at restoring them. This study evaluated the abundance of this species in the upper Paraná River floodplain over a 26-year time series in sites under different degrees of protection. Despite the overall decrease in the abundance of S. brasiliensis across the region, the less impacted sites have higher abundances and exhibited a slower decline in the probability of occurrence. Over time, populations in less impacted sites also exhibited improved fish condition. Some protected areas in the upper Paraná River have had a mitigation effect by lowering the velocity of population decline and representing a constant source of propagule production for other areas. Our results reinforce the notion that populations threatened with low abundances take a long time to effectively recover their stocks. Thus, besides evaluating species conservation strategies, long-term studies are essential to subsidize management measures, such as fisheries regulations.
{"title":"Importance of protection strategies in the conservation of the flagship species “dourado” Salminus brasiliensis (Characiformes: Bryconidae)","authors":"R. M. Dias, Oscar Peláez, T. M. Lopes, A. G. Oliveira, M. A. Angulo-Valencia, A. Agostinho","doi":"10.1590/1982-0224-2022-0046","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0046","url":null,"abstract":"Abstract In the upper Paraná River floodplain, the populations of Salminus brasiliensis have been subjected to several anthropic impacts, such as overfishing, the blocking of migratory routes by dams, and regulation of the flood regime. Its populations have disappeared or become depleted in most rivers in this basin. These populations are the target of protection measures aimed at restoring them. This study evaluated the abundance of this species in the upper Paraná River floodplain over a 26-year time series in sites under different degrees of protection. Despite the overall decrease in the abundance of S. brasiliensis across the region, the less impacted sites have higher abundances and exhibited a slower decline in the probability of occurrence. Over time, populations in less impacted sites also exhibited improved fish condition. Some protected areas in the upper Paraná River have had a mitigation effect by lowering the velocity of population decline and representing a constant source of propagule production for other areas. Our results reinforce the notion that populations threatened with low abundances take a long time to effectively recover their stocks. Thus, besides evaluating species conservation strategies, long-term studies are essential to subsidize management measures, such as fisheries regulations.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199751","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 : 2022-01-01DOI: 10.1590/1982-0224-2022-0051
Laís Caldas, A. M. Cherobim, F. Langeani
Abstract The genus Harttia belongs to the subfamily Loricariinae and has to date 27 described species, distributed in the drainages of Guiana Shield, Amazon and southeastern Brazil. The new species is distinguished from its congeners by the combination of: canal plate present; abdominal plates absent; trapezoid preanal plates; males with elongated and conspicuous odontodes on the first pectoral-fin ray and on the lateral region of the head, close to the canal plate; and dorsal-fin spinelet present. An identification key for the species of the rio São Francisco basin and a comparison between the new taxon and all other species of the genus are presented.
Harttia属Loricariinae亚科，目前已发现27种，分布于圭亚那盾地、亚马逊河流域和巴西东南部。新种与同系物的区别在于:管板存在;腹部板无;四边形肛前板;雄鱼在第一胸鳍上和在头部的外侧区域，靠近管板上具长而明显的齿状突;有背鳍小刺。本文给出了里约热内卢s o Francisco盆地的物种识别键，并将该新分类单元与该属所有其他物种进行了比较。
{"title":"A new species of Harttia from the rio São Francisco basin (Siluriformes: Loricariidae)","authors":"Laís Caldas, A. M. Cherobim, F. Langeani","doi":"10.1590/1982-0224-2022-0051","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0051","url":null,"abstract":"Abstract The genus Harttia belongs to the subfamily Loricariinae and has to date 27 described species, distributed in the drainages of Guiana Shield, Amazon and southeastern Brazil. The new species is distinguished from its congeners by the combination of: canal plate present; abdominal plates absent; trapezoid preanal plates; males with elongated and conspicuous odontodes on the first pectoral-fin ray and on the lateral region of the head, close to the canal plate; and dorsal-fin spinelet present. An identification key for the species of the rio São Francisco basin and a comparison between the new taxon and all other species of the genus are presented.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199759","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 : 2022-01-01DOI: 10.1590/1982-0224-2021-0158
G. B. N. D. Paula, Mariane Gavazzoni, C. H. Zawadzki, C. Fernandes, A. L. Portela-Castro, R. L. Lui, V. P. Margarido
Abstract Hypostomus is the most specious genus of Hypostominae, composed of several species with high intraspecific morphological and color pattern variation, making their identification a complex issue. One of the species with problematic identification is Hypostomus tietensis that was described from a single specimen, resulting in uncertainties about its color pattern and correct identification. To assist in this context, cytogenetic analyzes were carried out in three putative populations of H. tietensis from the Upper Paraná River basin, one of them from the type locality. The three populations showed considerable cytogenetic differences, with 2n = 72 chromosomes for the population from the type locality and 2n = 76 chromosomes for the others. Terminal NORs were detected (Ag- and 18S rDNA-FISH), being simple for the type locality population (acrocentric pair 23, long arm) and the Pirapó River (subtelocentric pair 11, short arm), and multiple for Do Campo River (subtelocentric pairs 11 and 12, short and long arm, respectively). C-banding was efficient in differentiating the type locality population from the others. Cytogenetic data revealed that populations from Pirapó and Do Campo rivers, although treated until now as Hypostomus aff. tietensis, represent a cryptic species, and those morphological analyses are necessary to differentiate and for describing this new species.
{"title":"Identification of cryptic species in allopatric populations of Hypostomus tietensis (Siluriformes: Loricariidae) through cytogenetics analyses","authors":"G. B. N. D. Paula, Mariane Gavazzoni, C. H. Zawadzki, C. Fernandes, A. L. Portela-Castro, R. L. Lui, V. P. Margarido","doi":"10.1590/1982-0224-2021-0158","DOIUrl":"https://doi.org/10.1590/1982-0224-2021-0158","url":null,"abstract":"Abstract Hypostomus is the most specious genus of Hypostominae, composed of several species with high intraspecific morphological and color pattern variation, making their identification a complex issue. One of the species with problematic identification is Hypostomus tietensis that was described from a single specimen, resulting in uncertainties about its color pattern and correct identification. To assist in this context, cytogenetic analyzes were carried out in three putative populations of H. tietensis from the Upper Paraná River basin, one of them from the type locality. The three populations showed considerable cytogenetic differences, with 2n = 72 chromosomes for the population from the type locality and 2n = 76 chromosomes for the others. Terminal NORs were detected (Ag- and 18S rDNA-FISH), being simple for the type locality population (acrocentric pair 23, long arm) and the Pirapó River (subtelocentric pair 11, short arm), and multiple for Do Campo River (subtelocentric pairs 11 and 12, short and long arm, respectively). C-banding was efficient in differentiating the type locality population from the others. Cytogenetic data revealed that populations from Pirapó and Do Campo rivers, although treated until now as Hypostomus aff. tietensis, represent a cryptic species, and those morphological analyses are necessary to differentiate and for describing this new species.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199928","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 : 2022-01-01DOI: 10.1590/1982-0224-2022-0070
L. F. C. Tencatt, W. Ohara, L. Sousa, M. R. Britto
Abstract An expedition crowdfunded by aquarists to a region of the Brazilian state of Pará drained by the Tapajós and Xingu river basins resulted in the capture of five species of Corydoras from the rio Jamanxim basin, a tributary to the rio Tapajós, of which three could be confirmed as new and described herein. The new species can be promptly diagnosed from their congeners by the combination of features related to color pattern and osteology. Considering the gathered information on color patterns and morphology plus field observations, the new species are considered to compose two distinct Müllerian mimicry rings, with two of them forming a mimetic pair, while the third one forms a pair with a fourth non-identified species captured in the same expedition. An identification key to the species of Corydoras from the rio Tapajós basin is also provided.
{"title":"Science and hobby joining forces for the discovery of three new Corydoras (Siluriformes: Callichthyidae) from the rio Tapajós basin, Brazil, with comments on Corydoras sp. CW111","authors":"L. F. C. Tencatt, W. Ohara, L. Sousa, M. R. Britto","doi":"10.1590/1982-0224-2022-0070","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0070","url":null,"abstract":"Abstract An expedition crowdfunded by aquarists to a region of the Brazilian state of Pará drained by the Tapajós and Xingu river basins resulted in the capture of five species of Corydoras from the rio Jamanxim basin, a tributary to the rio Tapajós, of which three could be confirmed as new and described herein. The new species can be promptly diagnosed from their congeners by the combination of features related to color pattern and osteology. Considering the gathered information on color patterns and morphology plus field observations, the new species are considered to compose two distinct Müllerian mimicry rings, with two of them forming a mimetic pair, while the third one forms a pair with a fourth non-identified species captured in the same expedition. An identification key to the species of Corydoras from the rio Tapajós basin is also provided.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67200485","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 : 2022-01-01DOI: 10.1590/1982-0224-2021-0117
G. Dutra, T. Ramos, N. Menezes
Abstract Three new species of Eigenmannia belonging to the E. trilineata species-group are described. The first species is described from rio Mearim basin and can be diagnosed by lateral line stripe restricted to last two thirds of body, superior midlateral stripe present, 176–205 anal-fin rays, 10–15 scales rows above lateral line, 109–125 lateral line scales, 19–23 premaxillary teeth, 20–29 dentary teeth, 6–10 endopterygoid teeth, and 13–14 precaudal vertebrae. The second species is described from upper rio Parnaíba, and can be diagnosed by lateral line stripe restricted to last two-thirds of body, ii,11–13 pectoral-fin rays, 180–196 anal-fin rays, 12–15 scales rows above lateral line, 10–14 premaxillary teeth, 15–21 dentary teeth, 8–10 endopterygoid teeth, and 14 precaudal vertebrae. The third species is widespread in rio Parnaíba basin, and can be diagnosed by absence of lateral line stripe, absence of superior midlateral stripe, 182–228 anal-fin rays, 12–15 scales rows above lateral line, 107–131 lateral line scales, 32–34 premaxillary teeth, 35–44 dentary teeth, 9–12 endopterygoid teeth, and 13 precaudal vertebrae. A dichotomous key and the conservation status for the three species are provided.
{"title":"Description of three new species of Eigenmannia (Gymnotiformes: Sternopygidae) from the rio Mearim and rio Parnaíba basins, Northeastern Brazil","authors":"G. Dutra, T. Ramos, N. Menezes","doi":"10.1590/1982-0224-2021-0117","DOIUrl":"https://doi.org/10.1590/1982-0224-2021-0117","url":null,"abstract":"Abstract Three new species of Eigenmannia belonging to the E. trilineata species-group are described. The first species is described from rio Mearim basin and can be diagnosed by lateral line stripe restricted to last two thirds of body, superior midlateral stripe present, 176–205 anal-fin rays, 10–15 scales rows above lateral line, 109–125 lateral line scales, 19–23 premaxillary teeth, 20–29 dentary teeth, 6–10 endopterygoid teeth, and 13–14 precaudal vertebrae. The second species is described from upper rio Parnaíba, and can be diagnosed by lateral line stripe restricted to last two-thirds of body, ii,11–13 pectoral-fin rays, 180–196 anal-fin rays, 12–15 scales rows above lateral line, 10–14 premaxillary teeth, 15–21 dentary teeth, 8–10 endopterygoid teeth, and 14 precaudal vertebrae. The third species is widespread in rio Parnaíba basin, and can be diagnosed by absence of lateral line stripe, absence of superior midlateral stripe, 182–228 anal-fin rays, 12–15 scales rows above lateral line, 107–131 lateral line scales, 32–34 premaxillary teeth, 35–44 dentary teeth, 9–12 endopterygoid teeth, and 13 precaudal vertebrae. A dichotomous key and the conservation status for the three species are provided.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199295","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 : 2022-01-01DOI: 10.1590/1982-0224-2022-0006
Luís Henrique Martins Capp Vergès, R. F. Contente, C. Marion, Cívil Prisyla Casado del Castillo, H. Spach, A. P. Cattani, L. F. Fávaro
Abstract The variability of fish assemblage structure with respect to seasonality in salinity and productivity remains to be elucidate to many Neotropical estuaries. In this study, we hypothesized that salinity gradient and a set of variables related to ecosystem productivity drive community parameters in the shallow-water fish assemblage of the north-south axis of the Paranaguá Estuarine Complex (Southern Brazilian coast). Samples were taken with beach seine monthly from May 2000 to April 2001. Supporting our hypothesis, richness and abundance increased with turbidity, warmer waters of the rainier summer seasons, which are more productive. This environmental setting favors reproduction, as well as juvenile recruitment and growth, whose intensities are highest in this period. Highest abundance was found in inner areas, which may be explained by greater food and habitat availability. Richness was higher in more saline waters, due to the proximity of the rich pool of marine fish species. We suggest that local human interventions (e.g., dredging) should be avoided during the rainy seasons that are critical for species life cycles. Salinization, low estuarine productivity, and warmer waters, which are expected with climate change and human impacts in the local watershed, could affect the integrity of the local fish assemblage.
{"title":"Relationship between fish assemblage structure and predictors related to estuarine productivity in shallow habitats of a Neotropical estuary","authors":"Luís Henrique Martins Capp Vergès, R. F. Contente, C. Marion, Cívil Prisyla Casado del Castillo, H. Spach, A. P. Cattani, L. F. Fávaro","doi":"10.1590/1982-0224-2022-0006","DOIUrl":"https://doi.org/10.1590/1982-0224-2022-0006","url":null,"abstract":"Abstract The variability of fish assemblage structure with respect to seasonality in salinity and productivity remains to be elucidate to many Neotropical estuaries. In this study, we hypothesized that salinity gradient and a set of variables related to ecosystem productivity drive community parameters in the shallow-water fish assemblage of the north-south axis of the Paranaguá Estuarine Complex (Southern Brazilian coast). Samples were taken with beach seine monthly from May 2000 to April 2001. Supporting our hypothesis, richness and abundance increased with turbidity, warmer waters of the rainier summer seasons, which are more productive. This environmental setting favors reproduction, as well as juvenile recruitment and growth, whose intensities are highest in this period. Highest abundance was found in inner areas, which may be explained by greater food and habitat availability. Richness was higher in more saline waters, due to the proximity of the rich pool of marine fish species. We suggest that local human interventions (e.g., dredging) should be avoided during the rainy seasons that are critical for species life cycles. Salinization, low estuarine productivity, and warmer waters, which are expected with climate change and human impacts in the local watershed, could affect the integrity of the local fish assemblage.","PeriodicalId":19103,"journal":{"name":"Neotropical Ichthyology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67199944","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}
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