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Arms as areas for larval development of migratory fish species in a Neotropical reservoir and the influence of rainfall over abundances
Author(s) -
Sanches Paulo Vanderlei,
Gogola Tatiane Mary,
Silva Rafael Olimpio,
Topan Dhyego Amilton,
Santos Picapedra Pablo Henrique,
Piana Pitágoras Augusto
Publication year - 2020
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.14474
Subject(s) - biology , larva , juvenile fish , ichthyoplankton , abundance (ecology) , juvenile , lake ecosystem , ecology , plankton , fishery , fish migration , habitat , zoology
The aim of the present study was to verify the use of the arms of the Itaipu Reservoir as areas of initial development for migratory fish species and to assess the relationship between rainfall and the spawning of migratory fish. Accordingly, fish larvae were collected from five arms of the reservoir from 2009 to 2016 using 0.5 mm plankton nets. Density was standardized as the number of larvae per 10 m 3 filtered water, and the captured larval and juvenile specimens were identified at the lowest‐possible taxonomic level. The larvae were also classified according to the degree of development and notochord flexion stage: larval vitelline, pre‐flexion, flexion and post‐flexion. To evaluate the distribution of larval abundance and the developmental stage along the longitudinal gradients of the arms, the data were evaluated using a set of nested linear models, following the AIC and Bayesian information criteria. In addition, an analysis of covariance was performed to investigate the influence of rainfall on the larval abundance of migratory species. During sampling, several species of economic and conservation interest such as Salminus brasiliensis and Pseudoplatystoma corruscans were collected . The larvae of the migratory fish taxa were captured from all sampled arms, which indicate them as areas of initial development. Nevertheless, it was observed that larval density increases from fluvial towards lacustrine zones inside the arms. Also, the present study verified that species, even in lentic environments, respond positively to rainfall stimuli in a manner similar to that exhibited by conspecifics in lotic environments. Such results reinforce the necessity of the protection of arms aiming at the conservation of this main group of species impaired by the construction of dams.