Abstract
The distribution of stock density and larvae of Atrina pectinata was examined in Deukryang Bay. Sampling of adult stock was seasonally conducted from 29 stations in the bay in May, August, and November 1995 and February 1996. And the larvae were sampled with interval of 3 to 7 days from 12 stations from July to October 1996. Seasonal abundance of the adult in number and in biomass were the highest in August ($18\;inds./m^2$) and in November ($2,790\;g/m^2$), respectively, at G1 station located in the most inner bay. In frequency distribution of shell height, the mode in May appeared in 10-14 cm group with 62%, and that of the other seasons in $15{\sim}19\;cm$ group. The larvae were also distributed mainly at G1 as the adult were. The larval abundance showed a periodical cycle which seemed to be related to lunar cycle. The highest abundance of the larvae occurred on August 16 with $8\;inds./m^3$, and then decreased continuously. With regard to frequency distribution of larval shell height, the larvae less than $200\;{\mu}m$ occurred from July to October. And the mode in July appeared in small size group ($200{\sim}249\;{\mu}m$) with 38%. These results mean that A. pectinata spawned from July to October, mainly middle July to middle August. The larval distribution showed the same geographical tendency to adult distribution. Both the adult and the larvae mainly distributed in the most inner bay and west area of Deukryang island, where was shallower, warmer, and higher primary productivity than the entrance area of the bay and east area of the island. However, larval abundance of A. pectinata in this study was so low compared to adult biomass. The reason for this unusual phenomenon should be understood with the detail research in future.
득량만에서 생산되는 키조개 Atrina pectinata 성체와 부유유생의 출현 분포를 조사하였다. 채집시기별 정점에 따른 키조개의 출현량은 8월에 만의 가장 안쪽 정점 G1에서 18개체/$m^2$로 가장 많이 출현하였고, 전중량은 11월에 정점 G1에서 $2,790\;g/m^2$으로 가장 높았다. 수심이 낮은 내만과 서쪽 해역은 수심이 깊은 만 입구와 동쪽해역에 비하여 자원량이 많았다. 키조개 유생 출현량은 8개체/$m^3$ 이하로 매우 적었다. $7{\sim}8$월의 경우, 음력 $3{\sim}4$일경을 중심으로 유생 출현량이 peak를 이루는 경향을 보였으며, $9{\sim}10$월에는 유생 출현량이 크게 감소하였다. 유생의 경우도 수심이 낮은 만의 안쪽과 득량도 서쪽 해역이 수심이 깊은 만입구와 동쪽해역에 비해 출현량이 많았다. 득량만에서의 키조개 유생의 출현량은 자원량에 비하여 매우 낮은 결과를 보였다. 그러나 자원량과 유생의 지리적 분포 특성은 서로 유사한 결과를 보였다. 수심이 낮고 육수의 유입이 많으며 유속이 약한 내만은 키조개 모패 자원량이 풍부할 뿐만 아니라, 산란된 유생이 분산되지 않아 유생의 서식과 성장에도 가장 적합한 해역이었다.
