Reprodução De Peixes De Riacho: Estado Da Arte, Métodos E Perspectivas

Abstract

Stream fish reproduction is still poorly studied in natural environments, especially in the Neotropical region. In this chapter, we recollect some characteristics of fish reproduction and some questions to guide current research, as: Does sexual dimorphism occur in the species? Which is the mode of reproduction? When and where does the species reproduce? Which environmental factors trigger reproductive events? When does the reproductive life begin? Which is the fecundity? Most of these questions can be answered when we have many specimens available, captured at different periods of the year, measured, weighed and dissected following appropriate protocols. Obtained data represent life history traits that allow to categorize the species in reproductive styles related to parental care and to determine their accordance to models of reproductive strategy associated with the predictability of environmental conditions. We highlight some aspects to be considered in current and future field and lab procedures, such as the recognition of sexual dimorphisms, the importance of naturalistic observation and lab procedures. We draw attention to the advances in studies on reproductive modalities in fish groups well represented in streams, such as inseminating characiforms and viviparous cyprinodontiforms. Finally, we highlight gaps, urgencies, and current perspectives for studies on the reproduction of stream fish, with emphasis on the need for basic studies of species biology, on the importance for building theoretical references and for the conservation of stream habitats in all Brazilian biomes.

Feeding ecology of Moenkhausia collettii (Steindachner, 1882) (Characiformes: Characidae) in streams in the eastern Amazon: Environmental factors and body size

“…The contribution of allochthonous items, comprising approximately 68% of the diet, corroborates the low primary production of tropical streams and their dependence on adjacent terrestrial vegetation, which is so important in the ecosystem processes of energy flow and nutrient spirals (Caramaschi et al, 2021). This is a direct and indirect source of food for fish in these ecosystems, providing items such as fruits, terrestrial insects, seeds, and organic matter (Benone et al, 2020; Uieda & Pinto, 2011; Zeni & Casatti, 2014).…”