Population Structure of Species of the Genus Cichla (Osteichthyes: Cichliformes) Introduced in Different Brazilian Regions

a Bibliographic Review

Abstract

Neotropical freshwater systems are essential refugia for global fish biodiversity. Tucunarés (Cichla spp) are endemic fishes of this biogeographic region, naturally occurring in Brazil and other South American countries such as Venezuela, Colombia, Bolivia, Peru, French Guiana, Guyana, and Suriname. The economic interest in the ornamental fish market, sport fishing, aquaculture, and, above all, reservoir farming have culminated in the widespread introduction of tucunarés in other river basins in Brazil and around the world. The present paper aimed to conduct a literature review on the population structure of different species of the genus Cichla introduced into non-native ecosystems in Brazil. The population structure was characterized by sex ratio, length and weight of individuals. Factors such as reproductive and feeding characteristics that contribute to the establishment of the populations were also commented on, as well as the possible impacts of the introduction of tucunaré on native ichthyofauna. Despite the difficulty of direct comparison of the data obtained in each article, tucunaré populations are well established in reservoirs, both in their natural range of occurrence and in the semi-arid northeastern and southeastern and central-western regions Brazil. Most of the studies identified in our search were conducted in reservoirs, reinforcing the importance of research on tucunaré in these environments. However, few studies focused on evaluating the structure of tucunaré populations themselves. Considering that these species have a high potential to cause negative impacts on native biodiversity, continuous population monitoring is essential to identify and mitigate possible impacts.