A review on the age and growth studies of freshwater fish in South America

Abstract

The small quantity of basic studies like age and growth estimates implies a lack of stock assessments and difficulties to make decisions related to fisheries management and biodiversity conservation. Therefore, we extensively and systematically reviewed the growth parameters of freshwater species from South America, with the following objectives: verify the existence of taxonomic patterns between asymptotic length and the growth coefficient; summarize the principal methods used and identify tendencies in their use; analyze the time between collection of the data and publication of the results; and verify possible latitudinal patterns in asymptotic length and the growth coefficient. A total of 199 articles covering 259 species were found. This work demonstrates the main gaps in the age and growth studies of freshwater fish from South America. Although there are well-studied basins such as Parana and some parts of the Amazon, most of the ecoregions remain without information or basic studies, and show the need for efforts to improve this situation to better understand the population dynamics of the species. Considering the L∞-K relationship, no evident latitudinal patterns were found, not even for species of the same order. Still, despite the wide use that the growth parameters have in the most diverse models and population studies, our analyses show that the data take a long time to be published, making more applied management and conservation studies unfeasible or, at least, harder. Finally, growth parameter data can contribute to minimize the lack of stock assessments, providing important information for use in management and biodiversity conservation.