민들조개 형망의 갈퀴에 의해 어획될 확률을 조개크기와 갈퀴간격 사이의 관계로부터 구했다. 이때 기존의 방법에서는 각장만을 이용했는데 여기서는 각장 이외에 각고(또는 각폭)에 의한 효과를 추가시켜 어획될 확률을 구하고 로지스틱 어획선택성 곡선에 적합시켰으며, 그식은 다음과 같았다. P=(equation omitted).민들조개의 경우 생물학적 최소형은 각장이 25mm인 것으로 알려져 있으며, 이 최소성숙각장에 대해 50% 어획될 갈퀴간격을 구하면 16.2mm이다. 따라서, 민들조개 형망의 적정 갈퀴간격은 기존에 사용하고 있는 12mm를 16mm로 늘리는 것이 자원보호상 바람직하며, 이것은 예망작업시 모래 속을 끄는 갈퀴의 갯수도 상대적으로 적어지므로 어구저항이 감소되어 연료가 절약되며, 선상에서는 작은 조개를 체를 이용하여 거르는 인력작업도 줄일 것으로 여겨진다.
The clam, Gomphina melanaegis, which is commonly called the sandy beach clam because of its habitat, is a valuable organism in the sandy coast of East Sea, Korea. It is frequently observed in large populations between 0.5 and 5 meters. We have released 50,000 seedling, ranging from the diameter of approximately 3 mm, 2007, and 1,000,000 seedling, ranging from the diameter of approximately 0.2 mm, plus 100,000 adult individuals, ranging from the shell length of approximately 20~40 mm, 2008 at Jinha beach. The spawning period of G. melanaegis, was from June to August, and the main spawning occurred in July. This investigation was carried out to elucidate population distribution on the stocking area of sandy beach clam, G. melanaegis. The relationship between shell length and ring radius in each ring was investigated as a regression line. The relationship between the shell length and shell height of released young clam was SH=1.0105SL-4.7764 (R2=0.7905). The relationship between the shell length and total weight of released young clam was TW=0.0013SL2.3966(R2=0.71). It draws a deduction that the ring of this clam was produced once a year during the duration between June and August.