• Journal of Aquaculture
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• v.10 no.4
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• pp.395-402
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• 1997

The study has been conducted in order to understand the inheritance of body color in the wild type zebrafish (zebra danio), Danio rerio, and its golden mutant (golden danio). The body color was also studied to determine the effect of golden coloration on the survival rate of zebrafish eggs and larvae up to 15 days after fertilization. Reciprocal monohybrid crosses between the wild and the golden type of zebrafish indicated that golden coloration was controlled by a single gene which had two alleles. Transmission of these alleles from parents to their progenies followed the principles of dominance and segregation based on Mendelian inheritance. Similar results from the reciprocal crosses implied that a locus for golden coloration was located on an autosomal chromosome. On the other hand, average survival rates from four different types of mating between, and within, zebra and golden danio suggested that golden coloration seemed to be associated with the survival rate of zebrafish, especially in its early embryonic stage. This indicated that homozygous recessive golden mutation was likely to weaken the golden danio's chance of survival.

• Journal of Aquaculture
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• v.4 no.1
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• pp.67-71
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• 1991

Sensitivity to ethylmethanesulphonate(EMS) on Ulva Pertusa Kjellman thalli was investigated as preliminary studies aimed at mutation breeding of seaweeds. When the thalli were grown in medium containing the mutagen no growth and about $20{\%}$ growth inhibition occurred at $0.05{\%}$ and $0.025{\%}$ EMS-mixed medium respectively. In the case the thalli were treated short time at high concentration mutagen solution followed by culture in control medium no growth and about $10{\%}$ growth inhibition occurred at 40 min. in $1.0{\%}$ and 80 min. in $0.5{\%}$ EMS solution respectively. Among the mutagenized tissues, some showed variation in growth from and cell color contrast to the mother tissue. The mutagenized tissue polypeptide pattern using sodium dodecyl sulphate-polyacrylamide gel electrophoresis was simiiar that of the mother tissue except about 6.6 kD polypeptides.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.325-334
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• 2023

The invasive red swamp crayfish, Procambarus clarkii, is native to south-central United States and northeastern Mexico. Recently, it has been being spreading in the wild in South Korea. However, its primary sources, introduction routes, establishment, and expansion in South Korea remain unclear. Here, we analyzed genetic diversity and population genetic structures of its domestic natural populations during early invasion, commercial stock from local aquaria (a suspected introduction source), and original United States population using mitochondrial COI gene sequences for 267 individuals and eight microsatellite markers for 158 individuals. Natural and commercial populations of P. clarkii showed reduced genetic diversity (e.g., haplotype diversity and allelic richness). The highest genetic diversity was observed in one original source population based on both genetic markers. Despite a large number of individuals in commercial aquaria, we detected remarkably low genetic diversity and only three haplotypes among 226 individuals, suggesting an inbred population likely originating from a small founder group. Additionally, the low genetic diversity in the natural population indicates a small effective population size during early establishment of P. clarkii in South Korea. Interestingly, genetic differentiation between natural populations and the United States population was lower than that between natural populations and aquarium populations. This suggests that various genetic types from the United States likely have entered different domestic aquariums, leading to distinct natural populations through separate pathways. Results of our study will provide an insight on the level of genetic divergence and population differentiation during the initial stage of invasion of non-indigenous species into new environments.

• Animal Systematics, Evolution and Diversity
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• v.12 no.4
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• pp.331-347
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• 1996

The geographic distribution and variation for Rhinogobius brunneus were surveyed by means of allozymic and morphological analyses and it was revealed that the Korean populations of R. brunneus comprise three distinct types, Type-A, Type-B, and Type-C, which show considerable differentiation to a degree of interspecific level(Rogers' S(1972): $S_{A-B}$=0.631, $S_{A-C}$=0.628, $S_{B-C}$=0.661). In addition, no evidence of gene flow among the types was found at sympatric area and it is assumed that reproductive isolation is completed. Moreover there is microhabitat segregation according to the distance from river mouth among each types and which segregation was regarded as a factor to facilitate reproductive isolating mechanism. Therefore, based on the evidence presented above, these three types of R. brunneus are considered as typical discrete species.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.167-176
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• 2012

In comparison of the body color of Zacco platypys from Korea, it was found that there were significant differences among geographical populations in the color of upper eye, snout tip and anterior margin of pectoral fin. In individuals with red upper eye the snout tip was red but in those with black upper eye red color did not appeared on the snout tip. There was no difference between male and female in this characteristic and it was expressed uniformly within the same population. So we divided Z. platypus into two types by the color of upper eye; R type with red upper eye and B type with black upper eye. Red band on anterior margin of pectoral fins appeared in all males of both R and B type populations but in females it appeared only in B type individuals. The two types shown different distribution pattern in Korean Peninsula. R type distributed in almost whole area but B type distributed only in southeastern part of the peninsula: Nakdong, Hyeongsan, Taehwa, Suyeong and Jinjeon River. In analysis of external morphology among two types of Z. platypus from Korea and Z. platypus from Japan, there were no significant differences. But they were relatively well separated in discriminant function analysis.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.305-308
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• 2013

This study was conducted to describe the external morphology of Platypus-koryoensis Murayama in immature stage, to determine each instar based on larvae head-capsule, and to measure individual and local variations in the number of mycangia of adult. Egg of P. koryoensis, had oval shape and lengths of the major and minor axis were $0.67{\pm}0.051$ mm and $0.41{\pm}0.053$ mm, respectively. Body colour of $5^{th}$ instar was gloss white with well-developed mandible. Larvae of P. koryoensis grew up to $5^{th}$ instar and each instar was clearly classified by head capsule width. Head capsule width for $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, and $5^{th}$ instar larvae were $0.35{\pm}0.004$ mm, $0.45{\pm}0.010$ mm, $0.67{\pm}0.039$ mm, $0.94{\pm}0.069$ mm and, $1.12{\pm}0.007$ mm, respectively. The colour of pupa was pale yellow and its length was $4.64{\pm}0.044$ mm. The number of mycangia per female had individual variations from 5 to 12 and 83% of the adults had from 6 to 8 mycangia. There was no significant difference in number of mycangia collected from between Namyangju region and Honchen region.

• Journal of fish pathology
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• v.16 no.3
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• pp.153-159
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• 2003

The high mortality of cultured juvenile turbot, Scophthalmus maximus occurred in Gochang on June, 2003. The diseased fish was lethargic with reduced feed intake. Grossly, these fish showed pale body, abdominal extension and exophthalmia. The dominant internal gross features of diseased fish were severely enlarged spleen, pale gills and/ or liver. Diseased fish histologically showed basophilic enlarged cells in the kidney, spleen, gill, heart, stomach, intestine, liver, pancreas and adipose tissue. Transmission electron microscopy (TEM) reveled hexagonal virions in the cytoplasm of necrotic cells. The viral particles lead a central electron-dense core and an electron translucent zone, and were 136-159 nm in diameter. These results suggest that the virus belonging to the iridoviridae was responsible for the mortality of cultured juvenile turbot.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.165-182
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• 2015

The snailfishes (Scorpaenoidei: Liparidae) is a large group requiring taxonomic reviews because of a potential taxonomic confusion due to its great similarity in external morphology between species and a variation of its body color with size. Molecular phylogeny and taxonomic review were conducted for 10 species in 3 genera reported around the Korean waters, which facilitate understanding interrelationship within its family, and further management of fisheries resources. Molecular phylogeny using mitochondrial COI (mtCOI) and nuclear RAG2 (nRAG2) sequences indicates that the reciprocal monophyly of the three genera (Careproctus, Crystallichthys, and Liparis) were supported except Crystallichthys matsushimae, being closely related to Careproctus notosaikaiensis in only mtDNA COI topology. Liparis ingens Gilbert and Burke (1912) was reported as a distinct species differing from L. ochotensis. However, in the present study, comparing L. ingens from Korea with L. ochotensis from Japan and Russia, the two species were well corresponded in their morphology and molecule, therefore, we suggest L. ingens to be treated as a junior synonym of L. ochotensis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.207-214
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• 1996

This study was conducted to obtain fundamental information on forage sorghum breeding in forage crop field of Livestock Experiment Station at Suwon from 1986 to 1991. The charcterization of sorghum germplasm was performed through 1986 to 1987, and after parental lines were selected from diverse sorghum germplasm on the basis of flowering date, plant height and several morphological characters for forage sorghum Fl hybrids. The range of variation of 50% flowering date and plant height were greater in order of forage sorghum sudangrass and male sterile line of grain sorghum. The average flowering date was earlier in sudangrass and male sterile line of grain sorghum than forage sorghum lines from the tested sorghum germplasms. And the average plant height was tall in order of forage sorghum, sudangrass and male sterile lines of grain sorghum. There were remarkable morphological variations between sudangrass lines and male sterile lines of grain sorghum such as plant color, leaf midrib color, glume color, seed coat color, head compactness and shape, awns, grain covering and 100 seed weight.