• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.17-22
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• 1972

This results concerning the growth of transplanting of the oyster seed, Crassostrea angulata and Ostrea Iurida, which were transplanted from Japan by air, and cultivated by the raft suspended method at the coast of Yeongoo-Ri, Koje-Goon, located on the southern coast of Korea from January to December 1970, are as follows, 1. The mean shell height of O. lurida was 36.4mm, and the shape of the shell was round and small. On the other hand, the mean shell height of C. angulata was 87.4mm and the shell length was 52.3mm, and the shape of the shell was oval and large, 2. O. lurida and C. angulata oysters grew well when the water temperature was above $16^{\circ}C$ and the specific gravity ranged from 1.0171 to 1.0236 from June to July. 3. There was a little difference in relative valiance between shell length and height of O, lurida but significant difference was shown in C. angulata from July to November. 4. The mortality rate of O. lurida was $35.2\%$ and that of C. angulata was $21.7\%$ respectively.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.343-347
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• 2012

The growth rates of offspring of selected abalone (SA), Haliotis discus hannai, population for rapid growth were compared to those of offsping of the control abalone (CA) at bred under the same condition. The growth traits (shell length, shell breadth and total weight) of SA were significantly faster than those of CA at this experiment. At the 45th day and 90th day, the growth rates in shell length of SA were estimated 31.7% and 17.8% faster than those of CA, total weight of SA were estimated 43.7% and 25.6%, respectively. Moreover, the relative growth rate between shell length and total weight of SA showed significant differences higher than one in CA at 90th day. The results suggest a possibility of improving the growth rate of cultured abalone using selection techniques.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.592-599
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• 2015

To investigate the characteristic of age and growth, samples of Megangulus venulosus were collected monthly by dredge in the coastal waters of Gangneung, Korea from January to December 2014. The age of M. venulosus was estimated by measuring the ring radius on the shell. Because the relationship between shell lengths and ring radii in each ring group was regressed well, each ring was considered as an annual growth ring. Based on the monthly variation of the marginal index (MI) of the shell length, it is assumed that the ring of this species was formed once a year during September and November. From the parameters calculated using the average length when the year ring was formed, the estimated von Bertalanffy growth equation were $SL_t=236.3(1-e^{-0.061(t+0.184)})$ in age.

• Journal of Aquaculture
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• v.11 no.4
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• pp.581-592
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• 1998

To know on the distribution and ecological characteristics of genus Corbicula field survey made from August 1997 to July 1998 in the North Kyungsang Province. Three species, i.e. Corbicula japonica, C. leand and C. papyracea, were inhabited in the North Kyungsang Provice. C. japonica was dioecious and oviparous species and C. leana and C. papyracea were monoecious and viviparous species.

• Journal of Aquaculture
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• v.11 no.2
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• pp.193-201
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• 1998

This study was carried out to investigate the enviromental quality and the growth of transplanted pen shell, Atrinna pectinata japonica. Followings are the results of growth of transplanted pen shell with respect to the shell size groups from the natural habitat (Usando) in May 1995, and cultivated upto November in the transplantated area (Soomoonri). The water depth of transplantated area andnatural habitat were 3m, 20~25m, respectively. The seawater temperature of the two culturing farms were ranged of 10.9~$27.8^{\circ}C.$, 8.5~$30.0^{\circ}C.$, respectively at the lowest in November adn the highest in July. The seawater salinity of the two areas were ranged of 29.54~35.26$^0\prime\infty$, 28.75~36.31$^0\prime\infty$, respectively at the lowest in July and the highest in November. The phosphoric acid ($PO_4$-P) of the two areas were 0.09~$1.14 ^{\mu}$g-at/l, 0.23~$1.33 ^{\mu}$g-at/l, respectively at the lowest in June and the highest in September. The bottom type of the two areas was a silty mud, 85.23% (82.17~87.26%) in natural habitat and 92.12% (90.76~92.94$^0\prime\infty$) in transplanted area. In this study area, phytoplankton were composed of 19 species. Of these 19 species, Skeletonema costatum was dominant species in seawater between natural habitat and transplantatied area, and 157 cells/ml, 165 cells/ml at August respectively. Stock of phytoplankton in transplantated area were more than those of natural habitat except June and November. The growth of shell length, shell height, total weight, soft part weight and posterior adductor muscle weight of pen shell on different size groups (SL 10, 10~15, 15~20, 20cm) were excellent in shell length of 10cm group, and 99.32%, 107.66%, 871.09%, 951.26% and 1,223.76%, respectively. The survival rate of pen shell was 98.10% in the shell length of 10cm groups, 90.35~94.76% in the others groups. The growth of shell length, total weight, soft part weight and posterior adductor muscle weight of pen shell in transplantated area were more 1.3, 2.6, 2.7 and 4.5 times than those of natural habitat.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.303-309
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• 2014

The development of Japanese geoduck, Panopea japonica, grown under culture conditions, has been examined through the morphological characteristics in fertilized egg, larvae and juvenile. Gametes were stripped from ripe broodstock and placed into two separate containers. Eggs were washed through a $40{\mu}m$ sieve and fertilized with dilute sperm solution. Developing larvae were maintained at $19{\pm}1^{\circ}C$. Fertilized eggs with $81.6{\mu}m$ diameter developed to trochophores within 14 h and to D-stage larvae ($116{\mu}m$ shell length) within 27 h. Larvae were spontaneously settled at shell length of $311{\mu}m$ after 20 days. The hatching from fertilized eggs and larval rearing were normally available in $18.5-21.5^{\circ}C$, and the growth was good in a cashmilon substrate, as well as sand. After rearing of day 108 from metamorphosis, the shell length of juvenile P. japonica reached 13 mm, and growth rate of shell length of the juvenile was $117.5{\mu}m/d$.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.307-315
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• 2011

Digestibility index of 12 phytoplankton species were invested during the larval development sizes. Ingestible size of phytoplankton varied depending on larval sizes: Isochrysis galbana, I. aff. galbana, Pavlova lutheri, Chlorella ellipsoidea, Nannochloris oculata was ingested 94.2-99.7% all larval sizes. Cheatoceros calcitrans, C. gracilis and C. simplex could ingest over 90.0% after umbo stage (mean shell length $189.3{\pm}13.8{\mu}m$). Phaeodactylum triconutum, Dunaliella tertiolecta and Tetraselmis tetrathele could not ingested D-shaped larvae (shell length $65.0-100.0{\mu}m$) but ingested 97.3-99.7%, 43.3-99.3%, 48.5-99.3% after then larval stages, respectively. But Thalassiosira weissflogii was ingested 1.0-1.7% only at full grown stage. Over 50.0% ingestion cell size was D-shape stage larvae with smaller than mean $102.3{\mu}m$ in shell length could ingest phytoplankton with $4.6{\mu}m$ in both major and minor axis and up to $9.3{\mu}m$ in minor axis basis for larger than mean $158.3{\mu}m$ in shell length, respectively. At all larval stages, phytoplankton with larger than $10.0{\mu}m$ in both major and minor axis could not be ingested.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.21-30
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• 1999

This study was carried out to describe the growth of Ruditapes philippinarum on Chohwa and Toksan tidal flat in Kwangyang Bay, from June 1994 to July 1995. On the Chohwa tidal flat, the mean gran size, organic content and chlorophyll-a of the surface sediment were the range of 2.50-4.46 , 4.99-5.11%, 14.53-19.90 $\mu\textrm{g}$ cm$\^$-3/, and on the Toksan tidal flat, 0.83-1.66 , 2.22-2.34%, 6.20-6.90 $\mu\textrm{g}$ cm$\^$-3/, respectively. The shell length of R. philippinarum increased rapidly from spring to summer, and gently from summer to autumn, and ceased during winter. Fresh weight increased during spring and autumn, and decreased during summer and winter. condition factors also showed the same variations of weights. Synthesized annual growth pattern of 4 year classes in shell length fitted the von Bertalnffy growth model well. The annual growth of weight fitted the Gompertz model relatively well. The values of w, initial shell growth rate, and AGR$\sub$max/, maximum weight growth rate, on the Chohwa tidal flat were lower than those on the Toksan tidal flat. Comparing the growth patterns in the same tidal flat, growth rate was higher on the lover tidal flat than those on the higher tidal flat. In conclusion, the Chohwa tidal flat maintaining higher density showed lover growth rate, because of relatively insufficient food supply and inhabiting space.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.205-214
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• 2008

To evaluate the aquaculture potential of a subtrophic noble scallop, Chlamys nobilis in Korean waters, nursery growth of the species was studied on two remote Jeju coasts, Jigwido and Ongpori. The early growth performance of the first 60 days after settlement was expressed as: $SL=0.1664e^{0.0579x}$ ($r^2=0.924$), where x stands for days after settlement and SL for shell length. The early spats sized 1 mm in average shell length became $4.1{\pm}0.8\;mm$ after a month of nursery culture, thereafter grew to $13.0{\pm}1.9$, $23.1{\pm}3.1$, $30.3{\pm}4.3$, and $33.6{\pm}5.2\;mm$ for consecutive 4 months in Jigwido coastal area. Mean growth gains (mean daily gains in parenthesis) were $76.7{\pm}7.7$ ($165.6{\mu}m$), $73.3{\pm}7.3$ ($154.0{\mu}m$), $69.4{\pm}8.4$ ($140.0{\mu}m$), and $68.7{\pm}8.5\;mm$ ($137.4{\mu}m$), in depths of 5, 10, 15, and 20 m, respectively. The growth rate was significantly decreased as cultured in deeper place (p < 0.05). As culturing density was higher, growth performance of the scallop was decreased in both locations. Overall, in our preliminary study, the growth performance of scallop in Korean waters was not better than that in Japan, but it seems to be worth doing further study for successful introduction to Korean waters.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.153-153
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• 2003

Reproductive cycle with the ovarian developmental phases, first sexual maturity of the female venus clam, Cyclina sinensis, was investigated by a histological study, and the number of spawned eggs and spawning frequency by artificial spawning induction of the clams were estimated. Samples were collected from the intertidal zone of Simpo, Gimje city, Korea between January and December, 2001. The reproductive cycle of this species can be classified into five successive stages; early active (February to April), late active (March to June), ripe (May to August), spent (July to September), and spent and inactive (September to February). The spawning period was once a year between July and August, a spawning peak was seen in July and August. Percentages of first sexual maturity of female clams of 25.1-30.0 mm in shell length were 64.3%, and 100% for the clams > 40.1 mm. The number of the eggs released from each clam by spawning induction increased as the size of clam in terms of shell length increased. The mean number of the eggs released from the second induction of spawning was 76.87% of the number of the eggs released in the first spawning. Our data indicated that the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.