• Applied Microscopy
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• v.30 no.4
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• pp.321-326
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• 2000

The ultrastructure of the fertilized egg envelope from pale chub , Zacco platypus belong to Cyprinidae was studied using scanning and transmission electron microscopes. The fertilized egg was an adhesive type, have a single micropyle resembling the pathway of sperm in the area of the animal pole. The micropyle was surrounded by 5 peaks of hill. An outer surface of the fertilized egg envelope was arranged by pore canals irregularly. In section of fertilized egg, the egg envelope consistes of three layers, an outer adhesive layer, a middle electron dense layer and an inner lamellae layer consisting of 9 layers. These ultrastructural characters of fertilized egg envelope from pale chub can be utilized in taxonomy of teleost.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.90-100
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• 1993

Ultrastructure of the larval hemocytes in Sericinus montela Grey was observed with the transmission and scanning electron microscope. The 5 cell types, according to Breh lin and Zachary(1986), identified in the hemocytes of the last instar S. montela larva were; prohemocyte, plasmatocyte, granular cell, spherule cell and oenocytoid. Prohemocytes could be easily charaterized by a relatively large nucleus nd poorly developed cytoplasmic organelles. Plasmatocytes were relatively large spindle-shaped or oval cells with fibrous bundles. The spindle-shaped plasmatocytes, especially, were characterized by a well developed, elongated nucleus. Granular cells had various granules, either morphologically or in electron density, and highly developed cytoplasmic organelles in the cytoplasm. They had numerous cytoplasmic processes. Spherule cells were characterized by cytoplasmic spherules containing fine materials, which are released into the hemolymph upon maturity of the cell. Oenocytoids consisted of electron dense materials and the organelles in cytoplasm were poorly developed.

• Applied Microscopy
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• v.32 no.4
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• pp.303-310
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• 2002

Spermatogenesis and sperm ultrastructure are investigated by means of light and transmission electron microscopy in the equilateral venus, Gomphina veneriformis which is dominant bivalve in the east coast of Korea. In the active spermatogenic season, testis consists of numerous spermatogenic follicles which is contains germ cells in the different developmental stage. The spermatogonia attached to spermatogenic follicle wall and has a large nucleus with electron-dense nucleolus. The spermatocytes are characterized by appearance of synaptonemal complex and well-developed Golgi complex. Nucleus of spermatid consists of numerous heterogeneous granules with high electron density. Karyoplasmic condensation, acrosome and flagellum formations are observed during spermiogenesis. Testicular matured sperms of sperm bundle consists of head, midpiece and tail. The head is about $8.5{\mu}m$ long and comprises a long nucleus and a bullet-like acrosome ($8.5{\mu}m$ in length). Acrosomal rod of microfilaments is observed in the lumen between nucleus and acrosome. The midpiece has four mitochondria. And tail has the typical '9+2' microtubule system.

• Applied Microscopy
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• v.30 no.3
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• pp.311-319
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• 2000

The gill morphology and ultrastructure of the fleshy shrimp, Penaeus chinensis were investigated by light and electron microscopy. Fleshy shrimp has dendrobranchiate gills. Gill has a longitudinal septum dividing them into afferent and efferent channel. Each gill lamella is covered by multi-layered thin cuticle of different electron density. The lamella basal cell is squamous and contains cytoplasm of electron dense. Simple epithelial layer consists of squamous epithelium contained large nucleus. The lamella pillar structures are characterized by the axial microtubules and lateral membrane interdigitations Secretory cells of AB-PAS negative are multicellular gland. In active gland each cell boundary is not apparent and the cytoplasm contains smooth endoplasmic reticula, mitochondria, membrane-bounded secretory vesicles of low electron density and granular resettes. In inactive gland each cell boundary is apparent and the cytoplasm is occupied with numerous small granules of electron dense. The well-developed rough endoplasmic reticula and Golgi apparatus are observed in the unicellular gland of alcian blue positive.

• Parasites, Hosts and Diseases
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• v.40 no.3
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• pp.107-112
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• 2002

A scanning electron microscopic study was performed on the surface ultrastructure of Pygidiopsis summa (Digenea: Heterophyidae) adults. Metacercariae were collected from gills and muscles of mullets (Mugil cephalus) caught in a known endemic area, and adult flukes were harvested from dogs after 8 weeks of experimental infection. The worm was calabash form with its posterior part broader than the anterior part. Tegumental spines were densely distributed over the body surface, except on the suckers and genital apparatus, and around the excretory pore. Well differentiated spines were observed on the anterior half of the body, with 14-16 tips ventrally, and 19-20 tips dorsally. On the oral sucker. three pairs of type I sensory papillae (uni-ciliated knob-like swellings) and one pair of type II sensory papillae (aciliated round-swellings) were observed on the anterior and posterior parts of the lip, respectively. On the lip of the ventral sucker, one pair of type II sensory papillae was distributed only on its posterior part. Sperms were seen emerging from or entering into the genital apparatus. The results showed that the surface ultrastructure of P. summa was unique among the heterophyid trematodes, especially in digitation of tegumental spines and in distribution of sensory papillae on oral and ventral suckers.

• The Korean Journal of Malacology
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• v.26 no.4
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• pp.311-316
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• 2010

Spermatid differentiations during spermiogenesis and mature sperm ultrastructure in male Crassostrea nipponica were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other bivalves. Mature spermatozoa consist of broad, cap-shaped acrosomal vesicle and an axial rod in subacrosomal materials on an oval nucleus showing deeply invaginated anteriorly, two triplet substructure centrioles surrounded by four spherical mitochondria, and satelite fibres, which appear near the distal centriole. The acrosomal vesicle of spermatozoa of C. nipponica resemble to those of other investigated ostreids. Especially, two transverse bands (stripes) appear at the anterior region of the acrosomal vesicle, unlikely 2-3 transverse bands (stripes) in C. gigas. It is assumed that differences in this acrosomal substructure are associated with the inability of fertilization between the genus Crassostrea and other genus species in Ostreidae. Therefore, we can use sperm morphology in the resolution of taxonomic relationships within the Ostreidea. The sperm is approximately $48-50{\mu}m$ in length including an oval sperm nucleus (about $1.0{\mu}m$ in length and $1.41{\mu}m$ in width), an acrosome (about $0.48{\mu}m$ in length and 0.30 in width) and tail flagellum ($46-48{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9 + 2 structure. These morphological charateristics of acrosomal vesicle belong to the family Ostreidae in the subclass Pteriomorphia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.270-275
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• 2003

Histochemical characteristic and ultrastructure of the mantle of the granular ark, Tegillarca granosa are described using light and electron microscopy. The mantle of the clam is composed of outer epidermis, connective tissue and inner epidermis. The simple epidermis consists of supporting cells, ciliated cells of the two types and secretory cells of three types. Connective tissue is composed of matrix, collagen fibers, muscular fibers and hemolymph sinus. The columnar supporting cell is covered with microvilli on the free surface. Ciliated cells are distributed in the inner epidermis with numerous cilia, microvilli and tubular mitochondria. Secretory cells could be classified into three types (A, B and C) with morphological features of the secretory granules. Type A secretory cells contains secretory granules with fibrous materials of high electron density Type B secretory cells are more abundant than the other cells, and contains secretory granules of membrane-bounded and high electron density. Secretory granules of the type C cells are divided into fibrous core layer and homogeneous peripheral layer. Type B secretory cells are abundant in the both epidermis of marginal mantle, while large number of type A and C secretory cells are evident in the outer epidermis of the central and umbonal mantle. This result showed that the outer and the inner epidermis of the mantle are related with shell formation and cleaning of the mantle cavity, respectively.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.159-165
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• 2011

The anatomy and ultrastructure of the digestive diverticulum of Saxidomus purpuratus were described using light and electron microscopy. The digestive diverticulum of dark green color was situated on the gonad and connected to stomach by a primary duct. Digestive diverticulum is composed of numerous digestive tubules. The epithelial layer of digestive tubule, which is simple, is composed of basophilic cells and digestive cells. Basophilic cells are columnar in shape, and the electron density is higher than that of the digestive cell. The cytoplasm has a well-developed endoplasmic reticulum, tubular mitochondria, Golgi complex and membrane-bounded granules of high electron density. Digestive cells are columnar in shape, with development of microvilli on the free surface. Pinocytic vasicles, lysosomes and numerous mitochondria were observed in the apical cytoplasm of digestive cells. The results of this study suggest that basophilic cells and digestive cells in the digestive tubule are specialized in the extracellular and intracellular digestions, respectively.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.126-133
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• 1999

Ultrastructure of the zona radiata and the micropyle of ripe eggs in the rainbow trout (Oncorhynchus mykiss), catfish (Silurus asotus) and loach (Misgurnus anguillicaudatus) were examined by light, scanning and transmission microscopes. The egg micropyle of rainbow trout and catfish consists of a funnel-shaped vestibule and a tapered canal transversing the zona radiata. The micropyle of rainbow trout and catfish showed the similar structure with flat pit and long canal. The micropylar wall showed the clockwise spiral structure in rainbow trout. The micropyle of the loach showed the type with a hollow pit leading into a short canal and the micropylar wall showed the counterclockwise spiral structure. There are numerous and various size pores at the surface area around the opening in every experimented fish. Interconnecting ridges were observed in the unfertilized eggs of every fish.

• Korean Journal of Ichthyology
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• v.28 no.3
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• pp.147-155
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• 2016

This study describes the cell type, ultrastructure and histochemical characteristics as a preliminary study for the research on integument of the smooth lumpsucker, Aptocyclus ventricosus in accordance with the physiological and environmental changes using light and electron microscopes. The SEM revealed the presence of well-developed finger printing structure in the skin surface. The skin surface of the smooth lumpsucker showed an irregular folds in cross section of light microscope. Integument is composed of outer epidermal and inner dermal layer. The epidermal layer is a stratified layer composed of epithelial cells, mucous cells, vacuolar cells, and granular cells. Epithelial cells are classified into superficial, intermediated, and basal cell. The superficial cells were the squamous with well-developed microridges on the free surface, and the microridges were covered with glycocalyx. The mucous cells of unicellular gland were mainly distributed in the apical layer of epidermis and contained mucosal materials of neutral glycoprotein. The vacuolar cells of unicellular gland were mainly distributed in the mid and basal layer of epidermis. The proportion of mucous cells and vacuolar cells were $7.0({\pm}1.07)%$ and $40.6({\pm}3.31)%$ of epidermal area, respectively. The granular cells contained membrane bounded secretory granules with high electron density and developed cell organelles in the cytoplasm. The dermal layer was loose connective tissue layer and composed of mainly collagen fibers. It also contained blood vessels and chromatophores of melanophores and reflecting platelets.