Mansour N, Lahnsteiner E
Institute for Zoology, University of Salzburg, Austria.
J Submicrosc Cytol Pathol. 2003 Jul;35(3):277-85.
Morphology of male genitalia and sperm fine structure of 4 siluroid fish, Callichthys thoracatus (Callichthyidae), Dysichthys coracoideus (Aspredinidae), Mystus armatus (Bagridae) and Ancistrus triradiatus (Loricariidae) were studied. In Dysichthys coracoideus and Ancistrus triradiatus the male genitalia consisted of paired testes and spermatic ducts but had no seminal vesicles. In Callichthys thoracatus the male genitalia had also paired seminal vesicles which were separated from the testis and emptied into the spermatic duct. Also in Mystus armatus seminal vesicles were found. They were not separated from the testes but the seminiferous tubules changed into seminal vesicle lobes which finally emptied into the spermatic ducts. All the investigated species had simply organized aquasperms typical for external fertilizing teleosts which were characterized by an ovoid or elliptoid head, by a small midpiece and by the absence of an acrosome. The spermatozoa of Dysichthys coracoideus and Mystus armatus were biflagellate, while they were monoflagellate in Ancistrus triradiatus and Callichthys thoracatus. The proximal centriole was reduced in Dysichthys coracoideus and Mystus armatus and the basal body attached to the nucleus. Single mitochondria were found in Dysichthys coracoideus, Ancistrus triradiatus, and Callichthys thoracatus. On the contrary, in Mystus armatus mitochondria were fused to a more complex chondriosome.
对4种鲇形目鱼类，即胸斑甲鲶（甲鲶科）、似棘甲鲶（棘甲鲶科）、斑鳠（鲿科）和三棘下口鲶（甲鲶科）的雄性生殖器形态及精子精细结构进行了研究。在似棘甲鲶和三棘下口鲶中，雄性生殖器由成对的睾丸和输精管组成，但没有精囊。在胸斑甲鲶中，雄性生殖器也有成对的精囊，精囊与睾丸分离并排入输精管。斑鳠中也发现了精囊。它们与睾丸不分离，但生精小管变成了精囊叶，最终排入输精管。所有被研究的物种都具有典型的、结构简单的水精子，这是体外受精硬骨鱼的特征，其特点是头部呈卵形或椭圆形，中段较小，且没有顶体。似棘甲鲶和斑鳠的精子有双鞭毛，而三棘下口鲶和胸斑甲鲶的精子是单鞭毛。在似棘甲鲶和斑鳠中，近端中心粒退化，基体附着于细胞核。在似棘甲鲶、三棘下口鲶和胸斑甲鲶中发现单个线粒体。相反，在斑鳠中，线粒体融合形成更复杂的线粒体。
