• The Korean Journal of Zoology
• /
• v.5 no.2
• /
• pp.13-17
• /
• 1962

The author colelcted crabs (Tribe Brachyura ) on the coasts of fourteen western islands of South Korea (Paenyong Do, Taechong Do, Sochong Do, Taeyonpyong Do, Kanghwa Do, Yongjong Do, Chagyak Do, Tokchok To. Moktok To. Pukkyoknyolbi Do. Ong Do, ANmyon Do, Pigum Do, and Taehuksan Do) mainly in summers during a period ranging from 1955 to 1962. Of these Islands, Paeknyong , Taehong, Taeyonpyong, Ong, Anmyon, Pigum and Taehuksan Do are the localities where the crabs were investigated firstly by the present author. The collections made by the author consist of 1779 specimens of crabs involving 9 families. 25 genera, 33 species and 5 subspecies (Table2). 23 species of crabs had been reported hitherto from Tokchok To and 7 from Kanghwa Do. In present paper the author adds 1 species to the fauna of crabs of Tokchok To and 7 to that of Kanghwa Do. In present paper the author adds 1 species to the fauna of crabs of Tokchok To and 7 to that of Kanghwa D. Among 38 species or subspecies of crabs collected, Oregonia gracilis, Cancer amphioetus and Chaesmagnathus convexus are new to the fauna of the west coast of Korea. 57 species of crabs are therefore identified in this area. The author collected Pinnotheres cardii on Taechong Do and Scopimera bitympana on Pigum Do. It became, therefore, clear that these two kinds of crabs occur much wider areas than known hitherto in Korea. The nothern limit of the distribution of Ocypoda stinpsoni and Sesarma haematocheir is Kyungki Bay as known already, that of Helice tridens is ,however, more northern part than Kyungki Bay, since they were collected on Paeknyong Do.

• Journal of the Korean Dietetic Association
• /
• v.20 no.4
• /
• pp.306-319
• /
• 2014

This study is basic research focused on product development and market activation based on analysis of current usage and demand for development of processed blue crabs. A total of 556 subjects aged 20s to 60s living in the Seoul area were surveyed. According to the survey, 65.1% of subjects consumed blue crabs at home, and 82% of them purchased blue crabs whole and undressed. Respondents gave higher marks to taste, nutrition, and texture compared to ingredient preparation, eating method, and price. Majority of blue crab consumers had no experiences of consuming processed blue crabs. Exactly 57.0% of consumers purchased them at big shopping centers, and the reason for purchasing was their good taste. When female consumers purchased processed blue crabs, they checked every part carefully compared to male consumers. Women gave high scores to blue crab powder, blue crab extract, blue crab croquette, and blue crab cake compared to men, demonstrating the necessity of developing processed blue crabs. Furthermore, the experienced processed blue crab group recognized the necessity of developing processed blue crabs compared to the inexperienced group. People showed significant differences in purchasing processed blue crabs according to gender as well as previous experience of blue crab consumption.

• Journal of Ecology and Environment
• /
• v.43 no.1
• /
• pp.31-42
• /
• 2019

Background: Han River estuary is a national wetland reserve near the Demilitarized Zone (DMZ) between South Korea and North Korea. This trans-boundary estuary area has been well preserved and shows distinctive plant communities along the salinity gradient. To elucidate energy flows and nutrient cycling in this area, we studied trophic relations between the dominant sesarmid crab, Sesarma dehaani, and food sources in three wetlands with different environments along the estuarine gradients. Results: Stable isotope signatures (${\delta}^{13}C$ and ${\delta}^{15}N$) of the crabs were significantly different among the sites and body size classes. Seasonal changes in ${\delta}^{13}C$ of small crabs were distinct from those of large individuals at all the sites. The isotopic values and fatty acid profiles of the crabs were more different among the sites in September than in May. In May, large-sized crabs utilized more plant materials compared to other dietary sources in contrast to small-sized crabs as revealed by a stable isotope mixing modeling, whereas contributions to diets of crabs were not dominated by a specific diet for different body size in September except at site 1. Based on PCA loadings, fatty acid content of $18:3{\omega}3$, known as a biomarker of plant materials, was the main factor to separate size groups of crabs in May and September. The ${\delta}^{13}C$ value of sediment had high correlation with those of small-sized crabs at site 1 and 2 when 1-month time lag was applied to the value for crabs during the surveyed period. Conclusions: Based on the stable isotope and fatty acid results, the consumption habits of S. dehaani appear to be distinguished by sites and their size. In particular, smaller size of S. dehaani appears to be more dependent on fewer food sources and is influenced more by the diet sources from the sediments in Han River estuary.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.1
• /
• pp.9-17
• /
• 2012

The relationship between adult abundance and zoea I (ZI) density of Dungeness crabs was investigated in southeastern Alaska. Commercial harvest data (catch per pot) for male crabs larger than 165 mm in carapace width were collected from the Alaska Department of Fish and Game (ADF&G) management area, district 114 and a subdivision of district 114, 114C from 1996 to 2003. Commercial harvests of Dungeness crabs in the management area varied interannually. Commercial harvests decreased until 2000 but increased beginning in 2001. ZI density was obtained from zooplankton samples collected monthly from sampling stations within the same management district from 1997 to 2004. ZI occurred mostly in May and June, but as late as July in 1997 and 2002. ZI densities increased beginning in 1999. Total densities of ZI were significantly correlated with the commercial harvest data of adult male crabs within the management area, 114C (tens of square kilometers), containing the plankton sampling stations, but were not related to total commercial harvests within the larger geographic management area 114 (hundreds of square kilometers). We suggest that larval density may be an indicator of abundance of adult populations of Dungeness crabs.

• Animal Systematics, Evolution and Diversity
• /
• v.15 no.1
• /
• pp.75-82
• /
• 1999

Three xanthid crabs from Chejudo island, viz., Forestia depressa (White, 1847), Pilodius nigrocrinitus Stimpson, 1858, and Palapedia integra (De Haan, 1835) are recorded as new to the Korean fauna. Up to data the Korean crabs of the family Xanthidae s. restr, consist of 15 species of 8 subfamilies.

• Korean System Dynamics Review
• /
• v.11 no.1
• /
• pp.27-57
• /
• 2010

This article deals with an ecological-economic analysis of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs using Jichun, a stream of the River Kum where the natural propagation of mitten crabs are blocked because of the estuary dam constructed in 1990. Toward analyzing the ecological and economic effects of the crab releasing and harvesting activities in Jichun, a two-stage cohort model of population dynamics with cannibalistic behaviors and density restrictions in biomathematics is adopted, despite of the current infertility in Kum, considering the opportunity of establishing dam fishways in the near future. This study moreover presents a method of parameter estimation especially with assuming a steady state of the ecosystem, and performs various analyses such as the risk measurement of climate change and the economic value of such fishways.

• Journal of Ecology and Environment
• /
• v.44 no.4
• /
• pp.207-211
• /
• 2020

Adult land crabs generally live on land while their larvae live in the sea. In the case of Sesarma haematoche, female crabs migrate from land to sea to release the larvae at the high tide of syzygy night. Artificial structures along coastal areas are being obstacles for the migration of land crabs and causing synchronized roadkills on coastal roads during breeding migration. In this research, we compared the sex ratios of crab populations in coastal areas with coastal roads and uninhabited island areas with no road. The proportion of females in inland habitats with coastal roads was significantly smaller than island habitats. In particular, females are exposed to the risk of annually repeated roadkills, and the proportion of females decreases rapidly with their growth. If this tendency is general for land crab populations in the coastal areas with roads, significant road mortality of female land crabs during breeding migration can lead to severe population decline in coastal areas. Therefore, it is necessary to take an action to save land crabs crossing coastal roads.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.45 no.4
• /
• pp.251-259
• /
• 2009

Swimming crabs, Portunus trituberculatus(Miers) are commercially important off the coasts of Korea, Japan and China. Harvest of swimming crabs has been fluctuated along their distribution ranges. Fluctuations in the interannual harvest of swimming crabs may be correlated with the survival rate during the larval period. The survival rates, intermolt periods, and growth of larval swimming crabs were investigated in the laboratory. Larval swimming crabs are released and undergo development from April to August off the western coast of Korea in the Yellow Sea. Sea surface temperatures off the western coast of Korea during the larval season were used for the laboratory experiments, and ranged from 22 to 26${^{\circ}C}$. Larvae were individually cultured at four different temperatures, 22${^{\circ}C}$, 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Zoea molted to megalopa at all temperatures and developed to the first crab stage at 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Survival rates from zoea I to the first crab stage increased with increasing temperatures. Intermolt period and the growth rate of the mean carapace length were inversely correlated with temperature. Our research helps understand the changes in survival rate and growth of larval swimming crabs resulting from changing oceanic temperatures. Further, our study suggests that the fluctuations in fishery harvest of swimming crabs off the coast of Korea may be related to changes in larval survival affected by changing ocean conditions.

• Korean System Dynamics Review
• /
• v.7 no.2
• /
• pp.97-120
• /
• 2006

This paper deals with the extension of and discussion on the System Dynamics model (Jeong & Jeon, 2005) of river crabs in Korea. The previous model has been elaborated to empirically search for the optimal restoration and harvest rates of crabs in the Imjin River, on the basis of theoretical models of population dynamics in the field of bio-mathematics and environmental economics. In this paper, the authors tries to couple a series of new feedback loops related to density restrictions and cannibalistic behaviors with a stage-structured model of the crab ecosystem, and also to endogenize the parameter of baby crabs' survival that is caused by water quality improvement and income increase. Through these extensions and relaxations, the authors are able to argue about the strategic decision of the optimal rates additional considerations as well as the properties of the integrated system that was not covered in the previous paper.

• Animal Systematics, Evolution and Diversity
• /
• v.27 no.2
• /
• pp.183-190
• /
• 2011

Three xanthid crabs, Liomera margaritata, Neoxanthops lineatus and Pilodius miersi, are described and illustrated for the first time in Korea. Liomera margaritata and N. lineatus are the first species of their genera to be found in Korea. The three species represent extensions of their previously known ranges and bring the number of known species of the xanthid crabs to 25 from Korean waters.