title: Sperm ultrastructure of Mytella (Bivalvia) populations from distinct habitats along the northern coast of São Paulo State, Brazil.
abstract: Ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. In the present work, spermatozoa of mussel specimens of the genus Mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. The objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate Mytella species. The specimens were from populations that live in intertidal zones on the southeast coast of Brazil, either buried in muddy-sand sediment or anchored to rocky substrates. The acrosomal vesicle was conical and long, the axial rod extended from the nucleus to the acrosome, the nucleus was an oblate spheroid with a condensed chromatin, the intermediate portion contained mitochondria encircling a pair of centrioles, and there was a single flagellum. The sperm was of a primitive type. The spermatozoon ultrastructure did not distinguish the specimens buried in muddy-sand sediment from those anchored to rocky substrates. The data suggest that the specimens analyzed, despite living in distinct habitats, belong to the same species, which conchological analyses identified as M. charruana. The presence of an axial rod in their sperm cells supports the inclusion of M. charruana in the subfamily Mytilinae.
authors: Departamento de Anatomia, Biologia Celular e Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, 13083-863 Campinas, SP, Brazil.
authors: Gisele Orlandi
authors: GO
authors: Introíni
authors: Fernanda Martins
authors: FM
authors: Maester
authors: Fosca Pedini Pereira
authors: FP
authors: Leite
authors: Shirlei Maria
authors: SM
authors: Recco-Pimentel
mesh_terms: D000177:Acrosome / Q000502:physiology / Q000648:ultrastructure*; D000818:Animals; D001938:Brazil; D017753:Ecosystem; D008297:Male; D046529:Microscopy, Electron, Transmission; D049879:Mytilidae / Q000166:cytology* / Q000502:physiology; D010772:Phosphotungstic Acid; D013082:Sperm Tail / Q000502:physiology / Q000648:ultrastructure*; D013194:Staining and Labeling
chemical_list: D010772:Phosphotungstic Acid