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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Korean Journal of Malacology
Journal Basic Information
Journal DOI :
The Malacological Society of Korea
Editor in Chief :
Volume & Issues
Volume 26, Issue 4 - Dec 2010
Volume 26, Issue 3 - Sep 2010
Volume 26, Issue 2 - Jun 2010
Volume 26, Issue 1 - Mar 2010
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Cryopreservation of Scapharca broughtonii (Schrenck) Sperm
Rha, Sung-Ju ; Han, Kyeong-Ho ; Choi, Myeong-Rak ; Kho, Kang-Hee ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 255~260
This study was conducted to investigate protocol standardization for spermatozoa cryopreservation of the Scapharca broughtonii (Schrenck). Among the freezing rates, freezing at a height of 2 cm above liquid nitrogen surface for 5 minute gave higher activity and survival rate. Among the various diluents, Ringer's solution was the best for S. broughtonii sperm cryopreservation. The suitability of cryoprotectants dimethylsulfoxide (DMSO), dimethylacetamide (DMA), glycerol and methanol were tested against three freezing rates. DMSO gave significantly higher activity and survival rates than others.
Reproductive Biology of the Purplish Washington Clam, Saxidomus prupuratus in the East China Sea
Kim, Young-Seop ; Kim, Yeong-Hye ; Kim, Jon-Bin ; Chang, Dae-Soo ; Lee, Dong-Woo ; Kang, Hyun-Jung ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 261~265
Reproductive biology of the purplish Washington clam, Saxidomus purpuratus was investigated based on the samples captured in Jinhae Bay, the East China Sea from January to December 2002. The gonad index (GI) began to increase in January, reached the maximum value in March. The reproductive cycle of this species can be divided into five successive stages: the early active stage (from November to January), the late active stage (from December to February), the ripe stage (from February to May and October), the spawned stage (from May to December), and inactive stage (from November to December). The spawning period was from April to December, and the main spawning occurred between June and August. The shell length at 50% group maturity was estimated to be 71.85 mm. The Sex ratio of this species was not significantly different a 1:1 sex ratio (P > 0.05).
Report on the sediment types, environmental parameters, density and biometry of Manila clam Ruditapes philippinarum in Gyeonggi Bay off the west coast of Korea
Park, Kwang-Jae ; Choi, Yong-Suk ; Heo, Seung ; Kang, Hee-Woong ; Han, Hyun-Seob ; O, Hae-Chong ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 267~273
From January to December 2007, we have investigated sediment types, environmental factors and density of clam Ruditapes philippinarum inhabited at Oeri, Naeri, Jonghyeon and Bangmiri tidal flats in Gyeonggi Bay off the west coast of Korea. Sediment types of Oeri and Jonghyeon were characterized with well sorted muddy sand. In contrast, Bangmiri tidal flat was mainly composed of poorly sorted gravelly muddy silt and Naeri was characterized with very poorly sorted muddy-sandy gravel. During the course of study, the surface water temperature, salinity, dissolved oxygen and pH ranged 3.2 to
, 21.7 to 33.3 ‰, 5.6 to 12.7 mg/l and 7.36 to 8.82, respectively. The suspended solid (SS) ranged from 3.2 to 1,266.0 mg/l and chlorophyll-a level in the water column ranged
, respectively. The density of clam in the study areas was mainly determined by the harvesting activities rather than the types of substrate. Relatively higher density of clam was observed in Oeri and Bangmiri where the clam seeds were sowed by the villagers. Condition factor of clams were found to be higher in Oeri where the substrate sorting was better with higher level of chlorophyll a. It was believed that sediment types and the level of available food the two governing factors controlling the density and growth of clam in Gyeonggi Bay.
Systematic Relationships of Korean Freshwater Snails of Semisulcospira, Koreanomelania, and Koreoleptoxis (Cerithiodiea; Pleuroceridae) revealed byMitochondrial Cytochrome Oxidase I Sequences
Kim, Woo-Jin ; Kim, Dae-Hee ; Lee, Jun-Sang ; Bang, In-Chul ; Lee, Wan-Ok ; Jung, Hyung-Taek ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 275~283
Many freshwater snail taxa are difficult to identify using morphological traits due to phenotypic plasticity. However, using of molecular DNA marker in combination with morphological traits can provide a reliable means for discriminating among freshwater snail taxa including cryptic species. To discriminate among Korean freshwater snail taxa and resolve their systematic relationships, wesequenced a fragment of mtDNA cytochrome oxidase I (COI) gene from 82 specimens collected from ten different sites distributed along the Korean peninsula. We identified more than seven freshwater snail taxa including cryptic species in Korea. Whereas traditional shell morphology of freshwater snails offers only weak discriminatory power for recognizing 'good' taxa, DNA sequence data provided positive and reliable identification. In addition, a major Semisulcospira clade was clearly separated from the remaining lineages observed including cryptic species. However, a phylogenetic tree inferred from the COI gene data did not fully resolve systematic relationships among pleurocerid taxa in Korea. Establishing more robust shell characteristics for identifying taxa unambiguously and hence improving traditional key shell morphology characters for freshwater snail species is an urgent requirement and will require more rigorous examination of all nominal taxa. While molecular data generated here will be useful for species identification and for describing the systematic relationships among Korean freshwater snails, further analysis will be required.
Species Identification and Genetic Structure of Octopus minor from Korea and China on the Basis of Partial Sequences of Mitochondrial Cytochrome Oxidase I
Kang, Jung-Ha ; Yu, Ki-Hwan ; Kim, Sang-Kyu ; Park, Jung-Yeon ; Kim, Bong-Seok ; An, Chel-Min ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 285~290
The nucleotide sequences of the mitochondrial cytochrome oxidase subunit 1 (CO1) gene of octopus groups collected from Muan, Taean, Yesu, Jeju in Korea and Youngsung, Daeryen in China were analyzed for the identification of species and populations. Six haplotypes were identified from the analyzed 60 individuals. All of the individuals (N = 10) from Jeju showed the A haplotype which was not observed from other groups, and could be classified as a distinct group. The analyzed groups could form two separate clade in MEGA4 analysis. The individuals from Muan, Taean, Yesu in Korea and Daeryen in China form a clase and the others from Jeju in Korea and Youngsung in China formed the other clade. The analysis of relationship among the groups showed the same results. Individuals belong to the group A (Muan, Taean, Yesu and Daeryen) showed closer relationship than individuals belong to the group B (Jeju and Youngsung). Although the CO1 universal primers used in this study was useful as a marker for species identification among Octopus, analysis of population was limited because of few variations in the partial sequences of CO1 analyzed in this study. However, it was possible to show the limited gene flow among the groups which is resulted from the spatial separation and differences in their habitats.
Stock Assessment and Management of Turban shell, Turbo (Batillus) cornutus Lightfoot, 1786 in Jeju Coastal waters, Korea
Kwon, Dae-Hyeon ; Chang, Dae-Soo ; Lee, Seung-Jong ; Koo, Jun-Ho ; Kim, Byung-Yeob ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 291~296
Samples of Turbo (Batillus) cornutus Lightfoot, 1786 in Jeju Island were collected from September 2009 to May 2010. Population ecological parameters and stock assessment of the turban shell were determined, based on the length and age composition data from 2000 to 2009 and ecological parameters. Instantaneous coefficient of total mortality (Z) of turban shell was estimated to be 2.2062/year. The estimated instantaneous coefficient of natural mortality (M) was 0.874/year. The age of turban shell at its first capture (
) was 2.636 year. Yield-per-recruit were estimated under harvest strategies that based on
was 10.44 g, 1.87 g, 6.53 g and 7.46 g.
Effect of Temperature, Salinity and Density on the Egg Development of the Sunray Surf Clam, Mactra chinensis
Min, Byeong-Hee ; Kim, Tae-Jin ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 297~302
Water temperature, salinity and density on egg development of the sunray surf clam, Mactra chinensis were investigated for artificial seedling production. The required time from fertilization to D-shaped larvae were 33.8 hours in
, 20.6 hours in
, 18.2 hours in
and 15.0 hours in
. The development duration was reduced with increasing temperature. The relationships between temperature and the required time from egg to each developmental stage were described as follows: 2-cell, 1/h = 0.1051WT - 1.4782; 8-cell, 1/h = 0.037WT - 0.3686; gastrula, 1/h = 0.008WT - 0.0521; trochophore, 1/h = 0.0041WT - 0.0235; D-shaped larva, 1/h = 0.0024WT - 0.0102. Biological minimum temperature for the egg development was estimated to be
in average. The possible range of temperature for the development of D-shaped larvae was
and optimum of water temperature for the development of egg was
. The possible range of salinity for the development of D-shaped larvae was 20-35 psu and optimum of salinity for the development of egg was 30-35 psu over 25 psu at least. The density of fertilized egg was below 40 per 1 ml in rearing seawater for elevating the development rate from fertilized egg to D-shaped larva.
Effects of Rearing Condition and Species of Microalgae on Growth and Survival of Larvae of the Sunray Surf Clam, Mactra chinensis
Min, Byeong-Hee ; Shin, Hyo-Jin ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 303~310
Rearing condition and species of microalgae on growth and survival of the sunray surf clam, Mactra chinensis larvae were investigated for artificial seedling production. The larvae of M. chinensis on higher temperature showed high growth and low survival and was grown over
in shell length 14 days after hatching, but low growth as
. The larvae of M. chinensis on salinity showed highest daily growth and survival as
and 65.8% at 30 psu, respectively. The optimum of water temperature and salinity for the larval rearing were
and 30-35 psu over 25 psu at least. The density of larval rearing was below 10 per 1 ml in rearing seawater for elevating the development rate from D-shaped to settled (metamorphosing) stage. The larvae fed the mixed diet of Isochrysis galbana, Pavlova lutheri, Isochrysis sp. (green), Chlorella ellipsoidea showed highest growth and survival. The larvae fed the single diet of I. galbana, Isochrysis sp. (green) showed high growth and survival. But the larvae fed the single diet of P. lutheri and C. ellipsoidea showed low growth and survival. The optimum diet of larvae of M. chinensis was over two species of microalgae included I. galbana, Isochrysis sp. (green) for elevating the high growth and survival.
Spermatid Differentiations During Spermiogenesis and Mature Sperm Ultrastructure in Male Crassostrea nipponica (Seki, 1934, Pteroirmorphia: Ostreidae)
Kim, Jin-Hee ; Chung, Ee-Yung ; Lee, Ki-Young ; Choi, Moon-Sul ; Seo, Won-Jae ; Kim, Sung-Han ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 311~316
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
in length including an oval sperm nucleus (about
in length and
in width), an acrosome (about
in length and 0.30 in width) and tail flagellum (
). 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.
Current Status of Genome Research in Phylum Mollusks
Bang, In-Seok ; Han, Yeon-Soo ; Lee, Jun-Sang ; Lee, Yong-Seok ;
The Korean Journal of Malacology, volume 26, issue 4, 2010, Pages 317~326
The availability of fast and inexpensive sequencing technology has enabled researchers around the world to conduct many genome sequencing and expressed sequence tag (EST) projects of diverse organisms. In recent years, whole genome projects have been undertaken to sequence ten species from the phylum Mollusca. These include Aplysia californica, Lottia gigantea, Crassostrea virginica, Spisula solidissima, Mytilus californianus, Biomphalaria glabrata, Crepidula fornicata, Elysia chlorotica, Lottia scutum and Radix balthica. Additionally, complete mitochondrial genomes of 91 mollusks have been reported. In Korea, EST projects have been conducted in nine mollusk species that include Nesiohelix samarangae, Pisidium (Neopisidium) coreanum, Physa acuta, Incilaria fruhstorferi, Meretrix lusoria, Ruditapes philippinarum, Nordotis gigantea, Crassostrea gigas and Laternula elliptica. Finally, the mitochondrial genome projects from the Pacific Oyster (Crassostrea gigas) and the rock shell (Thais clavigera) have been conducted and reported. However, no systemic mollusk genome project has so far been conducted in Korea. In this report, the current status and research trends in mollusk genome study in Korea will be discussed.