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Spermatology of the genus Lepidodasys Remane, 1926 (Gastrotricha, Macrodasyida): towards a revision of the family Lepidodasyidae Remane, 1927
Author(s) -
Guidi Loretta,
Pierboni Lara,
Ferraguti Marco,
Todaro M. Antonio,
Balsamo Maria
Publication year - 2004
Publication title -
acta zoologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.414
H-Index - 37
eISSN - 1463-6395
pISSN - 0001-7272
DOI - 10.1111/j.0001-7272.2004.00172.x
Subject(s) - biology , acrosome , genus , flagellum , zoology , sperm , clade , spermatogenesis , phylogenetic tree , anatomy , botany , genetics , gene , endocrinology
The spermatozoa of Lepidodasys unicarenatus and Lepidodasys sp. are filiform and composed of a cork‐screw shaped acrosome, a helical nucleus surrounding a mitochondrial axis, and a 9 × 2 + 2 flagellum as in the basic structural model of the macrodasyidan sperm. The genus Lepidodasys has a debated phylogenetic position and has been linked in turn to the family Lepidodasyidae and the family Thaumastodermatidae. The sperm features of the two Lepidodasys species examined are distinct from those typical of the two families: the absence of the periaxonemal cylinder, a character shared only with Turbanellidae among Macrodasyida, could be considered as a symplesiomorphy, suggesting a basal position of the genus along the Macrodasyida clade. Moreover, a comparison of the spermatogenic process of Lepidodasys sp. with those of Acanthodasys aculeatus (Thaumastodermatidae) and Cephalodasys maximus (Lepidodasyidae) has revealed that the process of acrosome formation and nuclear morphology during spermatogenesis are peculiar in Lepidodasys sp. and differences are evident especially in the late stages of spermatogenesis. Penetrated spermatozoa were observed in the oocytes at all maturation stages in L. unicarenatus.