Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River
ABSTRACT Diversity patterns and their causes remain important questions, especially for ecosystems that preserve natural conditions. This is the case of fish diversity in large Neotropical rivers. In this context, we investigated fish diversity patterns along an extensive unregulated river section (...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Sociedade Brasileira de Ictiologia
2019-12-01
|
| Series: | Neotropical Ichthyology |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000500210&tlng=en |
| _version_ | 1818731625600516096 |
|---|---|
| author | Marthoni Vinicius Massaro Lucas Adriano Pachla Rodrigo Bastian Fernando Mayer Pelicice David Augusto Reynalte-Tataje |
| author_facet | Marthoni Vinicius Massaro Lucas Adriano Pachla Rodrigo Bastian Fernando Mayer Pelicice David Augusto Reynalte-Tataje |
| author_sort | Marthoni Vinicius Massaro |
| collection | DOAJ |
| description | ABSTRACT Diversity patterns and their causes remain important questions, especially for ecosystems that preserve natural conditions. This is the case of fish diversity in large Neotropical rivers. In this context, we investigated fish diversity patterns along an extensive unregulated river section (ca. 450 km) in the Middle Uruguay River Basin. Sampling was conducted seasonally between May 2017 and March 2018, at six sites (patches) with contrasting environmental conditions. We collected 3,008 individuals belonging to 90 species. Nine were migratory, which summed relevant biomass in local assemblages (20 to 60%). We observed spatial variation in assemblage structure, but weak seasonal effects. Overall, biomass was similar among sites, but richness tended to increase downstream. Migratory fishes showed opposed trends, with higher richness and biomass upstream, particularly catfishes (Siluriformes). Ordination analyses separated sites in three groups based on variations in composition and abundance, and revealed associations between these groups and specific hydro-geomorphic conditions (i.e., flow, depth, channel width and the presence of riparian vegetation). Our study revealed that fish diversity distributes heterogeneously along the main channel, where hydro-geomorphic patches select for distinct assemblages along riverine gradients. |
| first_indexed | 2024-12-17T23:20:39Z |
| format | Article |
| id | doaj.art-8b7cf6c5dbd84c3fbf9ff20e4630185d |
| institution | Directory Open Access Journal |
| issn | 1982-0224 |
| language | English |
| last_indexed | 2024-12-17T23:20:39Z |
| publishDate | 2019-12-01 |
| publisher | Sociedade Brasileira de Ictiologia |
| record_format | Article |
| series | Neotropical Ichthyology |
| spelling | doaj.art-8b7cf6c5dbd84c3fbf9ff20e4630185d2022-12-21T21:28:55ZengSociedade Brasileira de IctiologiaNeotropical Ichthyology1982-02242019-12-0117410.1590/1982-0224-20190043Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay RiverMarthoni Vinicius Massarohttps://orcid.org/0000-0003-3816-6623Lucas Adriano Pachlahttps://orcid.org/0000-0003-1381-7477Rodrigo Bastianhttps://orcid.org/0000-0001-8868-7457Fernando Mayer Pelicicehttps://orcid.org/0000-0002-9700-1194David Augusto Reynalte-Tatajehttps://orcid.org/0000-0002-9853-4830ABSTRACT Diversity patterns and their causes remain important questions, especially for ecosystems that preserve natural conditions. This is the case of fish diversity in large Neotropical rivers. In this context, we investigated fish diversity patterns along an extensive unregulated river section (ca. 450 km) in the Middle Uruguay River Basin. Sampling was conducted seasonally between May 2017 and March 2018, at six sites (patches) with contrasting environmental conditions. We collected 3,008 individuals belonging to 90 species. Nine were migratory, which summed relevant biomass in local assemblages (20 to 60%). We observed spatial variation in assemblage structure, but weak seasonal effects. Overall, biomass was similar among sites, but richness tended to increase downstream. Migratory fishes showed opposed trends, with higher richness and biomass upstream, particularly catfishes (Siluriformes). Ordination analyses separated sites in three groups based on variations in composition and abundance, and revealed associations between these groups and specific hydro-geomorphic conditions (i.e., flow, depth, channel width and the presence of riparian vegetation). Our study revealed that fish diversity distributes heterogeneously along the main channel, where hydro-geomorphic patches select for distinct assemblages along riverine gradients.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000500210&tlng=enDiversityFloodplainMigratory fishRiparian vegetationRiver channel |
| spellingShingle | Marthoni Vinicius Massaro Lucas Adriano Pachla Rodrigo Bastian Fernando Mayer Pelicice David Augusto Reynalte-Tataje Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River Neotropical Ichthyology Diversity Floodplain Migratory fish Riparian vegetation River channel |
| title | Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River |
| title_full | Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River |
| title_fullStr | Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River |
| title_full_unstemmed | Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River |
| title_short | Seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the Middle Uruguay River |
| title_sort | seasonal and longitudinal variation in fish assemblage structure along an unregulated stretch of the middle uruguay river |
| topic | Diversity Floodplain Migratory fish Riparian vegetation River channel |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000500210&tlng=en |
| work_keys_str_mv | AT marthoniviniciusmassaro seasonalandlongitudinalvariationinfishassemblagestructurealonganunregulatedstretchofthemiddleuruguayriver AT lucasadrianopachla seasonalandlongitudinalvariationinfishassemblagestructurealonganunregulatedstretchofthemiddleuruguayriver AT rodrigobastian seasonalandlongitudinalvariationinfishassemblagestructurealonganunregulatedstretchofthemiddleuruguayriver AT fernandomayerpelicice seasonalandlongitudinalvariationinfishassemblagestructurealonganunregulatedstretchofthemiddleuruguayriver AT davidaugustoreynaltetataje seasonalandlongitudinalvariationinfishassemblagestructurealonganunregulatedstretchofthemiddleuruguayriver |