• Korean Journal of Ichthyology
• /
• 제20권3호
• /
• pp.163-166
• /
• 2008

The spermatozoal ultrastructure of Acheilognathus yamatsutae was studied using transmission electron microscopy. The mature spermatozoa are similar to those of other cyprinids as follows: a spherical nucleus with a shallow nuclear fossa, a short midpiece containing mitochondria and a long flagellum. However, there are some differences from other cyprinids in the orientation and position of the centrioles, the number of mitochondria, and the structure of vesicles. The position of the proximal centriole was of two types: one located on the side of nucleus decline, the other situated on the opposite side.

• Korean Journal of Ichthyology
• /
• 제23권2호
• /
• pp.106-110
• /
• 2011

Fine structure of spermatozoa of the bastard halibut (Paralichthys olivaceus) is described. Its structure is characterized by acrosomeless, having a spherical head region and a small mid piece containing five mitochondria disposed one row. The flagellum inserts centrally on the nucleus and has lateral ribbons. The present study supports the suggestion that spermatozoal ultrastructure is of taxonomic importance and may be a phylogenetic criterion in teleostei.

• Fisheries and Aquatic Sciences
• /
• 제9권1호
• /
• pp.1-6
• /
• 2006

Mature spermatozoa of dark chub Zacco temmincki (Temminck and Schlegel), were examined under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The spermatozoa have a spherical, homogeneously electron-dense nucleus with an axial nuclear fossa containing two laterally oriented centrioles. The centrioles, which are arranged at about a $120^{\circ}$ angle to each other, have the 9+2 microtubule structure typical of flagella. The mature spermatozoon is of the primitive anacrosomal aquasperm type. The nuclear envelope is strongly undulated and contains nuclear vacuoles of different sizes and positions. The midpiece contains six or more mitochondria and encircles the basal body of the flagellum with an axoneme covered by the plasma membrane. Cytoplasmic vesicles lie between the axonemal doublets and the plasma membrane, and encircle the anterior part of the tail. The plasma membrane of the flagellum extends laterally and forms a pair of side fins. The species showed minor differences in number and structure of mitochondria, the angle between centrioles, and total length and occurrence of the fins. These characters, especially the side fins, appear to be apomorphic and useful for determining phylogenetic relationships at the genus or family level.

• Applied Microscopy
• /
• 제28권1호
• /
• pp.63-71
• /
• 1998

The spermatozoon of Squalidus gracilis majimae is approximately $36.6{\mu}m$ in length and is characterized by a spherical nucleils with the clear chromatin, a short midpiece containing the mitochondria, and a flagellum positioned tangentially to the nucleus. An acrosome is absent as in all teleost fishes. The nucleus is about $1.9{\mu}m$ in diameter and in its periphery contains the electron-lucent chromatin distinguished from the electron-dense chromatin occupying most of the nucleus. The shallow nuclear fossa contains the proximal centriole, instead of two centrioles in deep nuclear fossa in siluroids. The proximal and distal centrioles are oriented approximately $140^{\circ}$ to each other. The mitochondria of 10 or more in number are arranged in three layers and do not surround the axoneme. The asymmetrical distribution of the mitochondria and the eccentrical position of the nucleus with regard to the tail are the general pattern of the cyprinid spermatozoa. S. gracilis majimae spermatozoa have the most mitochondria and the deepest cytoplasmic canal among cyprinid species. The flagellum lacks the lateral fins.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• 제32권6호
• /
• pp.730-736
• /
• 1999

The roundnose flounder's (Eopsetta grigorjewi) spermiogenesis and fine structure of the spermatozoon were examined by means of the scanning and transmission electron microscopy, During the spermiogenesis, the chromatin of the spermatid became fine granular form, and progressively condensed into many large globules, finally homogeneously condensed in the spermatozoan head. The main characteristics of the spermiogenesis were the disappearanre of Golgi complex, the appearance of microfilament the reduction of mitochondria and the appearance of Iysosome in the cytoplasm. A spermatozoon consisted of head and tail, but the acrosome was absent. The cytoplasmic collar containing seven mitochondria was observed in the posterior part of the head. The well-developed axonemal lateral fins were observed in the tail. The cross section of the axial filament showed '9+2' axonemal structure of microtubules, and the numerous vesicles were observed in the cytoplasm.