First phylogenetic analysis of spiders (Araneae) based on sperm morphology

MICHALIK, P.; RAMÍREZ, M. J.

Salta, Argentina

Congreso; II Congreso Latinoamericano de Aracnología; 2008

Universidad de Salta

Spiders are characterized by an astonishing diversity in sperm morphology at superfamily, family, and genus level. Despite the high amount of potential phylogenetic information that sperm characters might offer in spider relationships, they have never been included in phylogenetic analyses to date. Here, we present the first approach to include such characters in ongoing analyses of spider phylogeny. Ninety species representing 40 families of spiders were investigated by means of transmission electron microscopy. Representatives include two families of Mesothelae, five families of Mygalomorphae, ten families of Haplogynae and 23 families of Entelegynae. We defined about 40 sperm characters at different organizational levels (cellular and aggregation level). Most of the sperm characters are related to the level of sperm cell organelles, e.g., shape of the nucleus and acrosomal complex, axonemal patterns, or centriole-associated structures. Characters were added to previous and ongoing morphological phylogenetic matrices and analyzed using parsimony. We discuss on the evolution of sperm structures and its contribution to spider phylogenetic relationships, and propose spermatozoal synapomorphies for the following taxa: Mesothelae, Mygalomorphae, Araneomorphae, Liphistiidae, Heptathelidae, Atypidae, Dipluridae, Haplogynae (excl. Filistatidae), Filistatidae, Segestriidae, Dysderidae, Oonopidae, Pholcidae, Ochyroceratidae, Sicariidae und Scytodidae, Mimetidae, Araneidae, Mysmenidae, Anapidae, Linyphiidae, Nesticidae and Theridiidae, Synotaxidae, the „RTA clade“, Philodromidae, Dictynidae, Anyphaenidae, Corinnidae, Sparassidae and Selenopidae.