Revisão da família Achiridae (Teleostei: Pleuronectiformes) com ênfase em espécies dulciaquícolas

Abstract

An amount of changes occurred during the evolutionary history of Actinopterygii which result on the currently presence of singular fish forms, such as the Pleuronectiformes, commonly knowledge as flatfishes. This order can be differentiated by the presence of both eyes on the same side of the head. This bizarre shape make that many doubts about the relationship of Pleuronectiformes with remains bone fishes are still present until the moment. The family Achiridae, between other Pleuronectiformes groups, is remarkable by the considerable number of species associated, or exclusively distributed on freshwater environments. Understand the relationships of this family can be useful to the knowledge about distribution patterns and how Achiridae diversified on distinct environments on America. Nevertheless, to propose hypothesis like these was important to known previously how these species were recognized and his phylogenetic relationships. In the present work, were revised taxonomic and morphological aspects of Achiridae species. Was performed also an anatomical description of Hypoclinemus mentalis and were evidenced variations founded on remain genera. Characters states were included on a matrix to retrieve information about phylogenetic relationships of the family Achiridae. Additionally were used molecular markers to verify the efficiency of this technique to the systematics of this group. The monophyletic status of Achiridae was corroborated in all analyzes performed. In the same way, most of the species were recognized. However, the recognition of some genus and his phylogenetic interrelationships were not congruent. In relation to taxonomic changes, here, Trinectes lineatus, originally described by Chabanaud, was again recognized by a distinct species. Additionally were proposed changes on the authorship of Achirus achirus and Achirus lineatus. The morphology and the genetic distances retrieved allowed the knowledge of Trinectes affinis, currently considered as synonymy of Trinectes paulistanus. Similarly, was identified two cryptic species inside the Achirus lineatus complex distributed on Atlantic coasts of Mexico. Between all available taxa was diagnosed four groups related to the type of environment occupied. Correlating this types with the topologies retrieved was verified the possibility of a freshwater origin of the family Achiridae, follow by independent events of estuarine and marine colonization during his evolutionary history.