• Title/Summary/Keyword: Bivalvia

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Food Habits of the Asian Paddle Crab, Charybdis japonica (A. Milne-Edwards) on the Jangbong Tidal Flat, Incheon, Korea (민꽃게, Charybdis japonica (A. Milne-Edwards)의 섭식생태)

  • Seo, In-Soo;Hong, Jae-Sang
    • Korean Journal of Environmental Biology
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    • v.27 no.3
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    • pp.297-305
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    • 2009

  • The Asian paddle crab, Charybdis japonica (A. Milne-Edwards) is an important fishery resource in Korea. Despite its common occurrence and commercial importance, few studies have been carried out on the life cycle and trophic ecology of these populations inhabiting on the tidal flat. Food habits of C. japonica populations were investigated on the Jangbong tidal flat, Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. Based on the examination of stomach contents from 257 individuals, the frequencies of occurrence and the relative volumes of food items were analysed. As a result, the crustaceans (the brachyura, the cirripedia and the harpacticoid copepoda), the echinoderms (the ophiuroidea) and the molluscs (the cephalopoda Loligo beka, the bivalves Bivalvia unid. and Mytilus galloprovincialis) were important food for this species. To examine ontogenetic shifts in diets, individuals of C. japonica were categorized into 2 different size classes (${\leq}60mm$ and ${\geq}61mm$ in carapace width) representing sexually premature and mature stages. The food items of the small crabs (${\leq}60mm$) were dominated by the crustaceans with the harpacticoid copepods constituting 84.6% of total prey number. The next group was the bivalves and the brachyurans. On the other hand, the large crabs (${\geq}61mm$) mainly feed on the bivalvia (Mytilus galloprovincialis and Bivalvia unid.), the brachyurans (Crab unid.) and occasionally the cephalopods and fishes. The difference in proportions of the main prey items among these two size classes was statistically significant. Therefore, the feeding habits of the portunid crab, C. japonica changed with growth.

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The Comparison of Protein Patterns of Several Species in Bivalvia by SDS Polyacrylamide Gel Electrophoresis (SDS Polyacrylamide Gel 電氣泳動에 依한 斧足綱數種의 蛋白質패턴의 比較)

  • Park, Won-Chul;Ha, Man-Joon
    • The Korean Journal of Zoology
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    • v.28 no.2
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    • pp.61-70
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    • 1985

  • SDS-polyacrylamide gel electrophoresis for the proteins obtained from the plasma, Scapharca subcrenata and suapharca broughtonii, and for the proteins of muscles of several species in Bivalvia was performed. The protein patterns of plasma showed little difference between S. subcrenata and S. broughtonii in lower molecular weight weight proteins. However, the protein patterns of muscles of other species, which wre used in this study, were more shown in the lower molecular weights than the higher molecular weights in difference. Thus it is thought be an interesting fact. The protein band of blood corpuscles, 17,800 dalton, was not appeared in S. broughtonii, but this band was appeared in S. subcrenata. Henceforth this is the significantly important difference in these two species. But the protein patterns obtained from muscles of the species did not show a difference in a range of molecular weights between 10,000 and 100,000 daltons. Meanwhile, several protein bands obtained from Meretrix lusoria were similar to those of Mercenaria stimpsona. Hence, in this study, 6 protein bands which exist all species in Bivalvia and 4 characteristic protein bands in S. subcrenata and S. broughtoniionly, were investigated. And in four species of Eulamellibranchia, two protein bands in comon and the characteristic band of 23,000 dalton which is belong to Meretrix lusoria and Mercenaria stimdsona, were found. The molecular weights of the characteristic protein patterns, which are contained in each species, were measured and compared.

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Two Unrecorded Molluscan Species (Atrina teramachii and Liocranchia reinhardti) from Korean Waters

  • Son, Min-Ho
    • The Korean Journal of Malacology
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    • v.25 no.2
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    • pp.91-92
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    • 2009

  • Two molluscan species belonging to Bivalvia (Atrina teramachii Habe) and Cephalopoda (Liocranchia reinhardti Steenstrup) were found new to the Korean malacofauna. The author report, consequently, two additional molluscan species new to the fauna with figures and remarks on slight morphological variation comparing to the original and previous descriptions.

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