Analise filogenetica da superfamilia Loricarioidea (Teleostei: Siluriformes) com base na ultra-estrutura da espermiogenese e dos espermatozoides / Phylogenetic analysis of superfamily Loricarioidea (Teleostei: Siluriformes) based on spermiogenesis and spermatozoa ultrastructure

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The order Siluriformes comprises the most diverse and widely distributed ostariophysan groups, presenting thirty-six families with approximately 480 genera and over 3.000 species. Among the neotropical siluriform lineages likely to be monophyletic is the superfamily Loricarioidea. The relationships among catfish families suggest that Loricarioidea is sister group of Amphiliidae, an African siluriform family. The Loricarioidea is constituted by six families: Nematogenyidae, Trichomycteridae, Callichthyidae, Scoloplacidae, Astroblepidae, and Loricariidae. Although the current knowledge of the relationships among siluriform families has been acquired on the basis on osteological characters, other data such as the spermiogenesis and spermatozoal ultrastructure seem be potentially useful in the clarification of the relationships of the groups. The aim of the present study was to develop a phylogenetic analysis of the superfamily Loricarioidea, using the ultrastructural characteristics of both spermiogenesis and spermatozoa as a test to evaluate the ability of this data in resolving the phylogenetic relationships inside the families, among families and in the order Siluriformes. The description of the ultrastructural characteristics of male germinative cells in 27 specimens of different families of Loricarioidea was presented. The general analysis of the data obtained revealed that when this class of reproductive ultrastructural characters is employed in a more restrict group, as the superfamily Loricarioidea, it is really informative and can strongly support the monophyly of some groups. However, the phylogenetics analysis using these characters is not informative at order level as the suggested groups are very incongruent with the available hypotheses for Siluriformes. Moreover, some characters that could represent synapomorphies, change to homoplasies considering the occurrence of the same characters in other unrelated groups. Then, the use these reproductive ultrastructural characters in phylogenetics analysis should be carefully planed to avoid erroneous conclusions

ASSUNTO(S)

morfology ( animals) biological evolution fishes (evolution) peixes - evolução evolução (biologia) morfologia (animais)

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