• Korean Journal of Ichthyology
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• v.21 no.2
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• pp.81-86
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• 2009

The spermiogenesis and mature spermatozoa of Pseudobagrus fulvidraco were described by means of scanning and transmission electron microscopy. Spermiogenesis is characterized by lateral development of the flagellum, nuclear rotation, deep nuclear fossa formation and compaction into thick granules. The spermatozoa exhibit a round head containing a nucleus that lacks an acrosome, and having a midpiece and a flagellum. The midpiece is small and has a short cytoplasm including several mitochondria separated from the tail by the cytoplasmic canal. The flagellum contains the 9+2 classical axoneme structure and has two axonemal fins. The presence of axonemal fins in the flagellum is a common character in Bagridae. The interrelationships among the Bagridae as well as other teleosts are herein discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.480-485
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• 2003

Morphology of the spermatozoa from the testes of the catfish (Pseudobagrus brevicorpus) was studied by transmission and scanning electron microscopy. The spermatozoa of P. brevicorpus are approximately $82.25\pm0.06\;{\mu}m$ in length and relatively simple cells composed of a spherical head, a short midpiece and a tail as in most teleost fish, The nucleus measuring about $2.00\pm0.02\;{\mu}m$ in length is depressed with a deep nuclear fossa of about $1.05\pm0.03\;{\mu}m$ in length three fifths of the nuclear length. The nuclear fossa contains the proximal and distal centrioles. The two centrioles are oriented approximately $150^{\circ}$ to each other. The mitochondria are arranged in two layers and their number is 12 or more. They are separated from the axoneme by the cytoplasmic canal. The axoneme is the 9+2 microtubular pattern and has inner but no outer dynein arms as in other bagrids. The axonemal fins were the closed to axonemal doublet 3 and 8. The axonemal fins and lost outer dynein arm are shared in Bagridae and the deep nuclear fossa is shared in Siluriformes. The axonemal fins observed in Bagridae and Amblycipitidae of Siluriformes might be the apomorphic character in Ostariophysi.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.252-257
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• 1989

The five species of family Bagridae in Korea were analyzed by numerical taxonomic method based on the twelve osteological characters of 110 cleared specimens. Family Bagridae of Korea was classified into genera Pseudobagrus and Leiocassis. Genus Pseudobagrus has P. fulvidraco, Pseudobagrus sp. and P. brevicorpus, and Leiocassis also has L nitidus and L ussuriensis. P. brevicorpus represented more closely relationships to P. fulvidraco rather than Pseudobagrus sp. in the morphological features of skeleton.

• Applied Microscopy
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• v.46 no.3
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• pp.150-154
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• 2016

The ultrastructure of fertilized egg envelope from Pseudobagrus fulvidraco belongs to Bagridae was investigated using light and electron microscopes. The fertilized egg was compressed spherical, light-yellowish, demersal, and adhesive. The size of fertilized egg is about $1.85{\pm}0.13mm$, perivitelline space is not well developed, and there were no appendicular structures on the outer surface of egg envelope and oil droplets in vitelline membrane under light microscope. The micropyle was located in the animal pole of fertilized egg. Adhesive reticular fiber was covered fertilized egg envelope. The thickness of egg envelope was about $3.7{\sim}4.2{\mu}m$, and the egg envelope consisted of two layers: an outer, electron-dense adhesive fibers layer and an simple inner layer with pore. Therefore, the ultrastructure of cross section of the fertilized egg envelope showed species specificity, but studies on the other species belongs to Bagridae were need to get correct information about common traits in family.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.182.2-182
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• 1997

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.159.4-159
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• 2003

No Abstract, See Full Text

• Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.196-199
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• 2007

The spermatozoa of Leiocassis nitidus are relatively simple cells composed of a spherical head, a short midpiece, and a tail, as in most Siluriformes. The ultrastructure is characterized by the following features: Acrosome absent, as in most teleosts; around nucleus about $1.8\;{\mu}m$ long, with a deep nuclear fossa containing the proximal and distal centrioles and mitochondria. Two centrioles approximately $180^{\circ}$ from each other; 10 or more mitochondria surrounding the axoneme (with a 9+2 microtubular pattern), arranged in two layers in the postnuclear cytoplasm and separated from the axoneme by the cytoplasmic canal. Two lateral fins on the same plane as the two central microtubules; doublets 3 and 8, which are ultrastructural characteristics of the sperma tail unlike other siluroids laking the lateral fins.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.117-137
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• 1990

The morphological characters of the family Bagridae living in the river systems flowing into the south and western seas of Korea were reviewed and a taxonomic revision was made. The family Bagridae was classified into two genera: Pseudobagrus and Leiocassis. Species corresponding to genus Pseudobagrus were P. fulvidraco, P. koreanus Uchida, sp. nov., P. brevicorpus, and genus Leiocassis were L. nitidus, L. ussuriensis, and L. longirostris. Among them Pseudobagrus koreanus Uchida, sp. nov. and P. brevicorpus are endemic species of Korea. As the intergeneric taxonomic characters, the outstanding morphological differences between genera Pseudobagrus and Leiocassis were distinguished in following characters; the serrated structure of pectoral spine, the length of barbels, the number of pectoral fin rays, the structure of cranial lateral line system and the fused state of 3-4 hypurals. Pelteobagrus fulvidraco and Coreobagrus brevicorpus recorded previously in Korea were classified as Pseudobagrus fulvidraco and P. brevicorpus, respectively. Pelteobagrus nitidus and Pseudobagrus ussuriensis are also changed to genus Leiocassis. The characters of interspecific classification belonging to genera Pseudobagrus and Leiocasis were the shape of caudal fin, the form of body, the length of body, the number of anal fin ray and the number of gill rakers. Pseudobagrus sp. was named into Pseudobagrus koreanus Uchida, sp. nov..

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.93-99
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• 2001

Skin mucous cells in the three regions of the body in Pseudobagrus fulvidaraco and Leiocassius nitidus were investigated using three histochemical methods (PAS, AB-PAS and HID). In the two species, components of mucous cell were not distinguished in each region, but presented a differences in position and type, size, and count in all regions. Mucous cells of P. fulvidraco were located in two layers, a superficial epithelial cell and the space within alarm substance cells (ASCs). Mucous cells of L. nitidus were situated only in the superficial epithelial cell layer. The size of mucous cells in the ASC layer were larger than those of the superficial epithelial cells for all measured values: diameter, length, width, and area. In the superficial epithelial cell layer, the average number of mucous cells within the three regions did not differ significantly between species by unpaired T-test, but the average number of those within two cell layers of P. fulvidraco had a similarity at each region by paired T-test. The dismilarity in dorsal and ventral regions in average number of ASCs between P. fulvidraco and L. niditus was confirmed by unpaired T-test.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.183.3-184
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• 2000

No Abstract, See Full Text