• Development and Reproduction
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• v.20 no.2
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• pp.65-79
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• 2016

We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was $23.0^{\circ}C$ and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.120-127
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• 2007

To investigate the skin of the flat-headed goby, Luciogobius guttatus, it was used 8 body regions such as the head, the upper and lower jaw, the chin, the back, lateral region, abdomen, and the operculum. The epidermis consisted of three layers: the outermost layer, middle layer and stratum germinativum (basal layer). The outermost layer consisted of rather flattened cells arranged in 1 to 4 layers and mucous cells. The middle layer consisted of large epidermal cells occupying the height of the epidermis with 1 to 10 layers, causing a web-shaped structure. Due to the large epidermal cells of the middle layer, L. guttaus had a thick epidermis. The large epidermal cell contains tonofilaments, lucent contents, and desmosome. The basal layer was comprised of a single layer having cuboidal cells. A large number of fine blood capillaries were found just under the basal layer. The dermis consisted mostly of stratum compactum with numerous blood capillaries but had no scale.

• Korean Journal of Biological Psychiatry
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• v.18 no.4
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• pp.232-238
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• 2011

Objectives Optimized voxel based morphometry (VBM) has been increasingly applied to investigate differences in the brain morphology between a group of patients with mild cognitive impairment (MCI) and control subjects. Optimized VBM permits comparison of gray matter (GM) volume at voxel-level from the entire brain. The purpose of this study was to assess the regional GM volume change measured by optimized VBM in MCI subjects compared to controls. Methods Twenty patients with MCI and 20 control subjects with normal cognition were recruited for this study. We applied the optimized VBM protocol to the image data including study-specific template and the modulation of the data with the Jacobian determinants. GM volume differences between the MCI subjects and the control subjects and their correlations with the neuropsychological performances were investigated. Results Optimized VBM analysis revealed GM volume reduction in hippocampus, precentral gyrus, insula and parietal operculum in the MCI group compared to the control group (family wise error corrected p < 0.05). Korean version of the Consortium to Establish a Registry for Alzheimer's disease (CERAD-K) word list recall scores were significantly correlated with the GM volumes of hippocampus, precuneus and posterior cingulate in the MCI group (FWE corrected p < 0.05). Conclusions The results confirm previous findings of atrophic changes in medial temporal lobe and parietal lobe in the MCI group and suggest that these abnormalities may be related with cognitive decline and prognosis in patients with MCI.

• Journal of Species Research
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• v.1 no.1
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• pp.4-34
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• 2012

Parastenocaris koreana sp. nov. is described based on examination of numerous adult specimens of both sexes from several localities in Korea. Scanning electron micrographs are used to examine intra- and interpopulation variability of micro-characters, in addition to light microscopy. The new species is most closely related to the Japanese P. biwae Miura, 1969, which we redescribe based on newly collected material from the Lake Biwa drainage area. The two species differ in size, relative length of the caudal rami, shape of the anal operculum, shape of the genital double somite, relative length of the inner distal process on the female fifth leg, as well as relative length of the apical setae on the second, third, and fourth legs exopods in both sexes. Detailed examinations of three disjunct populations of P. koreana reveal also some geographical variation, especially in the surface ornamentation of somites, which may indicate some population structuring or even cryptic speciation. Lack of intraspecific variability in the number and position of sensilla on somites, as well as their potential phylogenetic significance, is a novel discovery. Both species examined here belong to the brevipes group, which we redefine to include 20 species from India (including Sri Lanka), Australia, East Asia, Northern Europe, and North America. A key to species of this group is also provided. In order to test the monophyly of the redefined brevipes group with highly disjunct distribution, as well as relationship between different species, a cladistics analysis is performed based on 39 morphological characters and with help of three outgroup taxa. Six equally parsimonious cladograms are generated, all of which show that the ingroup is well defined by at least three synapomorphies. Reconstructed phylogeny questions the previously suggested hypothesis about the origin of this group in South East Asia, with one Australian species showing the most basal position. We speculate that the present distribution of this group may be a combination of ancient vicariance and subsequent dispersal, with a possible origin in the Gondwanaland, in the rift valley between Australia and India.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.564-568
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• 2004

Odontoma, hamartomas of odontogenic orgin, are composed of all the structures that make up teeth, which may lead to interference with the eruption of its associated tooth. On the basis of gross, radiographic, and microscopic features, two types of odontoma are recognized: compound and complex. The etilogy of odontomas is unknown, although local trauma, infection, and gentic factors have been suggested. Odontomas occur central in bone between the roots of teeth and the mauority are asymptomatic. Although these tumors occur frequently and constitute 22% of all odontogenic tumors, are very rare. Erupted odontoma are defined as tumors that it occurs a calcifed mass may be defected on the ridge. The treatment of chico is the surgical removal of the lesion followed by a biopsy. This report presents a case of 8-year-old girl with the delayed eruption of the mandibular first molar by the calcified mass within the operculum covered the central fossa. And it was diagnosed as erupted complex odontoma by excisional biopsy.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.299-302
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• 2019

A clonorchiasis case in a captive leopard cat, Prionailurus bengalensis euptilurus, was confirmed by ultrasonographic findings and egg morphologies found in the bile juice sample in the Korea. The leopard cat was introduced from the wild habitat of Gyeongsangnam-do, to Cheongju Zoo in Cheongju-si, Chungcheongbuk-do, Korea in August 2014. Physical examinations were basically performed for quarantine and check-up health. The cat was comparatively good in health except anorexia. The cyst-like bile duct dilation and the increased echogenicity of gall bladder wall and hepatic parenchyma were observed by ultrasonography. Ultrasound-guided needle biopsy was conducted for collecting bile juice and the specimens were observed under light microscope. The numerous small trematode eggs were detected in the bile juice sample of the light microscopy. The eggs were $25-33(28{\pm}3){\mu}m$ by $18-22(20{\pm}1){\mu}m$ in size and showed typical characteristics of Clonorchis sinensis egg, i.e., a dominantly developed operculum, shoulder rim and dust-like wrinkles in surface. To treat the liver fluke infection, 20 mg/kg of praziquantel was orally administered only once to the case. Follow-up studies including fecal examinations were conducted during 2 years after treatment. But no more eggs were detected from the case. In the present study, we described the first clonorchiasis case of leopard cat, which was confirmed by ultrasonographic findings and egg morphologies from the bile juice sample in Korea.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.173-180
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• 2001

The fertilized eggs of Hyporhampus sajori (Temminck et Schlegel) were collected on the shore of Youngil Bay, Phohang-shi, Korea, on May 27, 1991, and were hatched and reared in the laboratory to investigate osteological development of larvae and juveniles. The newly hatched larvae were 7.00~8.50 mm (mean 7.80 mm, n = 5) in total length (TL) and had an ossified cranium, visceral skeleton and shoulder girdle bones. At 8 days, the larvae had attained 10.07~14.75 mm (mean 13.07 mm, n = 5) in TL had elongated dentaries anteriorly, and their vertebral columns were posteriory ossified. At 14 days, the larvae had attained 17.62~19.35 mm (mean 19.20 mm, n = 5) in TL, had ossified pterygiophores, and 41 slender ribs on the vertbrae. At 16 days, the larvae were 18.90~24.72 mm (mean 23.00 mm, n = 5) in TL and had three ossified epurals. Ossification of the jaw bone and operculum of the newly hatched larvae, which was related to feeding and respiration was almost completed 37 days after hatching.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.125-130
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• 2012

We describe early morphological development in laboratory-reared specimens of the brown croaker, Miichthys miiuy, in relation to fin differentiation, head dimensions, and squamation. From the yolk sac stage to the flexion larval stage (a period of 12 days following hatching, at which time the larvae were <4.2 mm in total length; TL) we observed the presence of a fin-fold around the body, while the caudal fin appeared rounded and lacked scales. Rays developed in the dorsal, anal, and pectoral fins in a process that was almost complete in larvae 12 days, while ray segmentation occurred between 26 and 29 days of age. Elongation of the middle rays of the caudal fin was initiated at 32 days, and the rays were remarkably elongated by 37 days. By 68 days the caudal fin was lanceolated (50.7 mm TL). Scales began to develop from the midlateral lines of the caudal peduncle at 9.1mm TL (28 days), eventually encompassing the entire operculum (22.1 mm TL; 44 days). The head dimensions were largely stabilized at >12 mm TL (30 day).

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.261-266
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• 2017

Microphysogobio koreensis is an endemic Korean freshwater fish that is protected as an endangered fish by the Ministry of Environment in Korea. In this study, we attempted to investigate the spawning period and spawning characteristics of M. koreensis to obtain basic information for its conservation. Though natural and histological observation, the spawning season occurred between April and May, with peak spawning occurred in early May when the water temperature was $20{\sim}23^{\circ}C$. During the spawning season, males had a bright-orange body and a thick red horizontal line from the rear of the operculum to the caudal peduncle, along with a lateral line, while females had a dark brown body. Nuptial organ had not appeared. The number of eggs in the ovaries was 10,705~22,165 ($15,573{\pm}4,274$). The number and appearance ratio of mature eggs were 1,100~5,920 ($3,383{\pm}2,126$) and 10.3~44.8% ($22.4{\pm}15.6$), respectively. And the size of mature eggs was 0.60~1.00 mm ($0.74{\pm}0.06$).

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.221-228
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• 2020

We studied the development of the endangered gold-spotted pond frog, Pelophylax chosenicus eggs and analyzed growth and survival rate of the tadpoles while feeding different feed to obtain the basic data on the its biological traits and reproduction. We observed the fertilized eggs of gold-spotted pond frog that naturally spawned in a breeding tank using a microscope. Fertilized eggs were sphere shape surrounded by colloid layers, clearly distinct with animal and plant poles. The fertilized eggs hatched 31 hours after fertilization and operculum complete at 175 hours after fertilization at water temperature of 27.0±1.0℃. As a result of growth and survival rate by different feed from 35 days after mouth open stage, vegetable feed (VF) group and tetra-min (T) group were significantly higher average weight gain rate (WG)(5843.9% and 5736.3%, respectively) and average specific growth rate (SGR) (11.67% and 11.62, respectively) compared with other groups (WG: 641.8~4625.2%, SGR: 5.72~11.01%). The vegetable (V) group showed the lowest growth rate (P<0.05). The average feed efficiency was 177.83% in the VF group, about 17 times higher than the V group. In addition, the average survival rate of the VF and T groups were the high at 97.5% and 100%, respectively, and the V group was the lowest at 32.5%. Therefore, the more efficient feeds for successful breeding is singly with VF or T.