The seasonal rate of discharge change as the primary trigger synchronizing freshwater fish reproduction in an Amazonian River

Autor(es)

Ropke, Cristhiana ; Cella-Ribeiro, Ariana ; Ferreira, Fabio Cop ; de Araujo, Tulio Raimundo ; Doria, Carolina Rodrigues da Costa ; Gusmao, Felipe ; Lonardoni, Alessandra ; Torrente-Vilara, Gislene

• Tipo de documento: Artigo Científico
• Fonte: Reviews in Fish Biology and Fisheries; v. 34, n. 4, p. 17-pg., 2024-09-19.

Resumo

Gaining a comprehensive understanding of all factors influencing fish reproduction in large rivers is vital for proposing improved river discharge management practices and estimating the impact of hydroclimatic changes, thereby supporting fish conservation efforts. However, the role of environmental variables as proximal cues for fish reproduction in tropical regions remains unclear. This study assesses the relative importance of discharge, the monthly rate of discharge change, dissolved oxygen, temperature, electric conductivity, water transparency, and depth in final gonadal preparation of fish in the Madeira River. Over approximately 500 km, we conducted a year-long monthly survey at 11 sampling sites near the mouths of eight tributaries. We determined the reproductive status of each captured fish for both migratory and non-migratory species. An index of reproductive intensity and species beta diversity was used to estimate the synchronism of fish reproduction. We found that the rate of monthly discharge change plays a pivotal role in explaining synchronism in final gonadal maturation. We observed a higher value of reproductive activity for both migratory and non-migratory fish assemblages during periods of significant increases in water flow, despite low overall discharge values. During this period, beta diversity was lower for migratory fish, suggesting a synchronized response among most species, while no clear pattern was observed for non-migratory species. This study provides compelling evidence that a significant and consistent surge in discharge, still during the lower discharge stages of the hydrometric cycle, serves as the primary proximal cue synchronizing the reproduction of rising-water spawner fishes in the Madeira River. (AU)

• Processo FAPESP: 22/05832-3 - Nível da água e precipitação modelando o sincronismo reprodutivo de peixes da bacia amazônica
• Beneficiário: Cristhiana Paula Röpke
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/50711-3 - Rede de modelagem de viabilidade econômico-ecológica, de pesca e cenários (SEAVIEW)
• Beneficiário: Luiz Felipe Mendes de Gusmão
• Modalidade de apoio: Auxílio à Pesquisa - Regular