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Sperm structure of Rhopalura littoralis (Orthonectida)
Author(s) -
Slyusarev George S.,
Ferraguti Marco
Publication year - 2002
Publication title -
invertebrate biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.486
H-Index - 42
eISSN - 1744-7410
pISSN - 1077-8306
DOI - 10.1111/j.1744-7410.2002.tb00049.x
Subject(s) - spermatozoon , biology , centriole , sperm , flagellum , acrosome , anatomy , cnidaria , turbellaria , ultrastructure , coral , ecology , botany , paleontology , bacteria
Abstract. We present here a description of the spermatozoon of Rhopalura littoralis , the first fine‐structural study of an orthonectid sperm. The spermatozoon contains a slightly elongate nucleus and two centrioles orientated along the longitudinal axis of the sperm. The proximal centriole bears one rootlet. A single mitochondrion is present in the mid‐piece region. An acrosome is absent. The sperm tail is a simple flagellum with 9+2 structure. We consider the orthonectan spermatozoon to be closer in structure to those of Porifera, Cnidaria, and Annelida, than to Aschelminthes and Platyhelminthes, to which orthonectids have previously been allied.