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Bessonart J, Loureiro M, Guerrero JC, Szumik C. Distribution of freshwater fish from the Southern Neotropics reveals three new areas of endemism and show diffuse limits among freshwater ecoregions. NEOTROPICAL ICHTHYOLOGY 2021. [DOI: 10.1590/1982-0224-2020-0153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract Ecoregions and areas of endemism are central concepts in biogeography. Based on collection records and the Endemic Analyses implemented with NDM/VNDM method we analyzed fish areas of endemism in the junction of three freshwater ecoregions related to the Rio de la Plata estuary (Lower Parana, Lower Uruguay, Laguna dos Patos) in Southern Neotropical region. Using two grid cell sizes, results obtained showed the same general patterns. Areas of endemism recovered were mainly associated either to Lower Uruguay or to Laguna dos Patos. In both ecoregions nested areas of endemism were identified within larger patterns of endemism. Noteworthy, one area recovered occurred across Lower Uruguay and Laguna dos Patos limits. Our results also suggest a revision of the Lower Uruguay and Lower Parana ecoregion limits, and highlight the relevance of the Rio de la Plata estuary as a barrier and corridor for freshwater fishes in the area.
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Tagliacollo VA, Dagosta FCP, Pinna MD, Reis RE, Albert JS. Assessing extinction risk from geographic distribution data in Neotropical freshwater fishes. NEOTROPICAL ICHTHYOLOGY 2021. [DOI: 10.1590/1982-0224-2021-0079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract The IUCN Red List (RL) provides high-quality conservation assessments for individual species, yet the rate and scale of environmental deterioration globally challenges the conservation community to develop expedited methods for risk assessment. Here we compare threat assessments for 3,001 species of Neotropical freshwater fishes (NFF) in the IUCN–RL using readily accessible data types as proxies for extinction risk: geographic range, elevation, and species publication date. Furthermore, using geographic and taxonomic data alone, we generated preliminary conservation assessments for 2,334 NFF species currently awaiting IUCN assessment, identifying an additional 671 NFF species as potentially threatened. This number of potentially threatened species represents an increase of 59% over the number of species currently assigned to threat categories by the IUCN–RL. These results substantially expand the number of threatened NFF species from 422 currently on the IUCN RL to 1,093 species as threatened or potentially threatened, representing about 18% of all NFF species. Extinction risk is greater in species with smaller geographic ranges, which inhabit upland rivers, and which were described more recently. We propose the Central and Southern Andes, and Eastern Guiana Shield as priorities in the upcoming IUCN RL assessment of NFF species conservation risk.
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Affiliation(s)
| | | | - Mário de Pinna
- 1 Museu de Zoologia da Universidade de São Paulo, Brazil
| | - Roberto E. Reis
- Pontifícia Universidade Católica do Rio Grande do Sul, Brazil
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Guedes GHS, Salgado FLK, Uehara W, de Pavia Ferreira DL, Araújo FG. The recapture of Leptopanchax opalescens (Aplocheiloidei: Rivulidae), a critically endangered seasonal killifish: habitat and aspects of population structure. ZOOLOGIA 2020. [DOI: 10.3897/zoologia.37.e54982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Leptopanchax opalescens (Myers, 1942) is a small seasonal killifish endemic to coastal drainages in the state of Rio de Janeiro, Brazil. Leptopanchax opalescens was recaptured in temporary open vegetation pools (22°42.35’S, 43°41.59’W) in the hydrographic basin of the Guandu River, state of Rio de Janeiro, Brazil, after eight years without records. Information on habitat and population parameters (Capture per unit area (CPUA), size, sex ratio and length-weight relationship (LWR)) are given to provide subsidies for the conservation of this species. Specimens were captured during the rainy season (January-April 2020) in shallow pools (mean depth = 21 ± 12 s.d. cm), with relatively acidic pH (5.2 ± 0.8) and low concentrations of dissolved oxygen (3.5 ± 1 mg/L). The estimated CPUA of the population was 0.89 fish/m2. The total length (TL) of males ranged from 21.1 to 28.8 cm, and females ranged from 17.0 to 31.2 mm. Males were significantly larger (t-test = 2.04, p < 0.05) than females, which were in greater proportion (2.83Female: 1Male, p < 0.001). A positive allometric coefficient (b = 3.19) was found through length-weight relationship curve, indicating that individuals of the species gain proportionally more increment in weight than in length. Leptopanchax opalescens is a critically endangered species, and the results of this study contribute to the knowledge of the distribution, population structure and conservation of the species and its natural habitats.
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Dias TS, Stein RJ, Fialho CB. Ontogenetic variations and feeding habits of a Neotropical annual fish from southern Brazil. IHERINGIA. SERIE ZOOLOGIA 2017. [DOI: 10.1590/1678-4766e2017020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
ABSTRACT Knowing the feeding biology of a population and its ontogenetic aspects can help in understanding the functioning of fish assemblages, essential to the conservation of the habitat biodiversity in which these species are found. Annual fishes complete their life cycle in temporary aquatic environments, existing in adult stage only for brief annual periods. Changes in the feeding habits between different size classes could indicate that a species belongs to different feeding groups in different growth phases. The aim of this work was to characterize the diet of Cynopoecilus fulgens Costa, 2002 in a temporary flooded area in the coastal plain of southern Brazil, taking into consideration possible alterations in feeding habits in different body size classes caused by ontogenetic changes, to explain the coexistence of these individuals in a short space of time. The diet analysis indicated that C. fulgens is a generalist, consuming small crustaceans and autochthonous insects. Intraspecific differences in diet were determined when compared between nine classes of standard length. Adults fed mainly on autochthonous insects, and juveniles ingested mostly crustaceans, with the population being separated into two trophic groups: invertivores and invertivores with a tendency towards zooplanktivory. It is possible to conclude that the ontogenetic changes in the diet of C. fulgens are related to morphological restrictions due to the size of the individuals, since feeding competitive relations are probably not so evident.
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Lanés LEK, Godoy RS, Maltchik L, Polačik M, Blažek R, Vrtílek M, Reichard M. Seasonal dynamics in community structure, abundance, body size and sex ratio in two species of Neotropical annual fishes. JOURNAL OF FISH BIOLOGY 2016; 89:2345-2364. [PMID: 27607142 DOI: 10.1111/jfb.13122] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non-annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non-annual fishes. The relative abundance of non-annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female-biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non-annual fishes were still present.
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Affiliation(s)
- L E K Lanés
- Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos-LECEA, Universidade do Vale do Rio dos Sinos-UNISINOS, Bairro Cristo Rei, São Leopoldo, Rio Grande do Sul, Brazil
- Instituto Pró-Pampa-IPPAMPA, Bairro Centro, Pelotas, Rio Grande do Sul, Brazil
| | - R S Godoy
- Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos-LECEA, Universidade do Vale do Rio dos Sinos-UNISINOS, Bairro Cristo Rei, São Leopoldo, Rio Grande do Sul, Brazil
| | - L Maltchik
- Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos-LECEA, Universidade do Vale do Rio dos Sinos-UNISINOS, Bairro Cristo Rei, São Leopoldo, Rio Grande do Sul, Brazil
| | - M Polačik
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic
| | - R Blažek
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic
| | - M Vrtílek
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic
| | - M Reichard
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic.
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