꽃게의 소리와 행동 (II)

SOUND PRODUCTION AND BEHAVIOUR OF CRABS, PORTUNUS TRITUBERCULATUS(MIERS) (II)

꽂게 (Portunus trituberculatus) 240미, 민꽂게(Charybdis japonica) 78미 등을 2월 21일 부터 8월 7일 까지 사육하면서, 이들이 먹이를 먹을 때 내는 소리를 녹음실의 간이 수조속에서 녹음하고, 행동을 관찰하였으며, 녹음된 소리를 증폭시켜 무향 수조 속에서 수중 스피커로 방성하였을 때, 수조속 꽃게들의 반응결과와 녹음된 소리를 분석한 결과를 요약하면 다음과 같다. 1. 꽃게들이 내는 소리의 음압은 크기별, 군별로 다르며, $52\~124db$이고, 주파수는 $250\~1000Hz$이다. 2. 꽃게의 내는 소리를 방성할때 추음효과는 약 $70\%$이다. 3. 꽃게의 추음속도는 $3\~6cm/sec$이며, 스피커에 도달한 게는 그곳을 떠나지 않는다. 4, 꽃게의 소리를 이용하여 음향어법에 적용할 때 꽃게의 크기는 갑장 $5.6\~6.5Cm$, 갑폭 $12.6\~15cm$인 암컷이 적당하다.

For the development of acoustic fishing method, we had been researched a fundamental study which concerned on the sound production and behaviour of crabs was conducted. For specimen crabs such as Portunus trituberculatus and Charybdis japonica were selected. Croaking noise were recorded by the Cassette-recorder (Sony model CF-1600) through the under water monitor microphone, and analyzed in frequencies by Octave band analyzer, Rion SA-55, and sound pressure level of source by sound level meter, SM-5844. The following are the results obtained from the present investigations : When sound production of crabs (Portunus trituberculatus( female ) : carapace width $12.6\~15$cm) were attracted to another crabs in the water of anechoic aquarium, efficacy of phonotaxis was $84\~100\%$ and velocity by phonotaxis was $6.5\~7.2cm/sec$. The time required for copulation ranged from 90 minute to 95 minutes by Charybdis japonica, at that time there was no sound production with their copulation.