• Proceedings of the Malacological Society of Korea Conference
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• 2001.11b
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• pp.146-148
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• 2001

• Proceedings of the Malacological Society of Korea Conference
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• 2001.11a
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• pp.50-52
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• 2001

• The Korean Journal of Malacology
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• v.17 no.2
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• pp.71-78
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• 2001

Age and growth of the pen shell, Atrina (Servatrina) pectinata japonica, on the west coast of Korea were studied based on 701 samples caught in April 1995 to March 1996. The results are summarized as follows: the relationship between shell height and ring radius in each ring group was expressed as a regression line. Therefore, it could be recognized that there is a correspondence in the formation of each ring. Based on the monthly variation of the marginal index (MI') of the shell, it was assumed that the ring of this species was formed once a year during the period of June to July. The relationship between shell height (SH) and total weight (TW) were expressed by the following equation TW = 5.906$\times$10/$^{-3}$SH$^{3.844}$. Shell length (SL) and shell height were highly correlated according to the following equation SL = 0.5277 SH +0.0934. The shell height-shell width (SW) relation was expressed by the following equation SW = 0.2681 SH -1.3757. Growth curves for shell height and total weight fitted to the von Bertalanffy's equation were expressed as: SHt=30.99(1-e-$^{-0.3212(t+0.9653)}$, TWt=657.94(1-e-$^{-0.3212(t+0.9653}$)$^{3.3844}$.

• The Korean Journal of Malacology
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• v.18 no.1
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• pp.53-59
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• 2002

The distribution and density of the pen shell, Atrina (Servatrina) pectinata japonica, were investigated to estimate population ecological parameters and biomass. Samples were collected during cruises from April to June 1999 in the coastal waters of Chungchung-namdo, Korea. The oceanographic conditions such as depth, temperature, transparency and suspended solids were measured from sampling stations. Seawater depth ranged from 3.9 m to 75.9 m and the mean was 28.5 m (SE = 0.97). The mean density of the pen shell was higher in the depth of 18.0-30.8 m. The water temperature of the bottom ranged from 7.0-21.5$^{\circ}C$ and the mean was 14.$0^{\circ}C$. The transparency ranged from 1.2-13.5 m and the mean was 4.8 m. The suspended solids ranged from 6.0-93.5 mg/l and the mean was 48.0 mg/l. The sand proportion of the sediment was > 50%. The mean densities of the pen shell by sediment type were 7.3 individuals/40 m$^2$ (SE = 2.16) in the sand, 5.6 individuals/40 m$^2$ (SE = 1.48) in the muddy sand, 3.0 individuals/40 m$^2$(SE = 1.89) in the sandy mud, and none in the mud. The sandy bottom, accounting for 29.8% of the overall habitat area, had a maximum density of 7.3 individuals/40 m$^2$.

• 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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.2
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• pp.106-115
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• 2013

A series of fishing experiments were carried out in the western coastal waters of Korea from May, 2006 to September, 2007, using gill nets of different mesh sizes (m=101, 121.8, 152.5, 176.8, and 191 mm) to determine the mesh selectivity of gill net for swimming crab, Potunus trituberculatus. The catch species was composed of swimming crab (87%), Thomas's rapa whelk Rapana venosa (5%), arthritic neptune Neptunea cumingi (2%), Japanese swimming crab Charybdis japonica (2%), marbled sole Pleuronectes yokohamae (1%), pen shell Atrina pectinata, ocellate spot skate Okamejei kenojei, and so on. The carapace length (CL) of each swimming crab caught in the experimental nets was measured. Sponge crab (egg-bearing female crab) was appeared from the end of June to August in the coastal waters. The master selection curve was estimated by applying the extended Kitahara's method. The selection curve showed that the gill nets of larger mesh size allowed more crabs of small carapace size to escape. The optimum value (CL/m) was 0.645 and the CL/m was estimated to be 0.301, 0.354, 0.391, 0.422, and 0.450 when the retention probabilities were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.529-535
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• 1984

This study aims at obtaining the basic data for the development of pen shell culture at Yoja Bay, the southwest coast of Korea. The authors dealt with the annual gonadal changes of the pen shell, Atrina pectinata japonica, to find out the gametogenesis, reproductive cycle and spawning season, and to investigate the fluctuation in the larval occurence in Yoja Bay. From July 1983 to June 1984, an average of 20 individuals as specimens were monthly collected by commercial fishing dredge near Manwol island located at the mouth of Yoja Bay. The degree of gonadal development was determined by the histological observations as resting spent stage, early developmental stage, after developmental stage, early spawning stage, after spawning stage and degenerative stage. According to these degrees of gonadal development, annual reproductive cycle of the pen shell population was determined. From July to August, the gonads were changed through degenerative into resting stage and, in September and October, they became entirely empty gonads. From November they showed the first sign of gametogenesis developing very slowly. Nevertheless, the developing gametes did not increase in number probably owing to a phagocytic phenomenon by phagocytes which appeared in the gonad during this stage. Some individuals started spawning in April and in May majarity of individuals were in spawning stage. In June, majority of the individuals showed signs of degenerative stage. Therefore, the authors came to a conclusion that the pen shells in Yoja Bay spawn chiefly in May. And this is also supported by the result of the survey on the planktonic occurrences of the pen shell larvae. Namely, there were no larvae at all in April, only a few in May and many in June by vertical water sampling.