The present study investigated the intra-vitam larval migration of Anisakis pegreffii, which is naturally infected, from the intestine to the viscera and the musculature of live spotty-bellied greenling, Hexagrammos otakii, under the different seawater temperatures. The results showed that the increase in the ratio of larval migration from the intestine to the viscera correlated with the increase in the water temperature in the aquarium. The intra-vitam larval migration ratios from the intestine to the viscera were 60% (63/105) at 15°C, 1.64% (3/183) at 12°C, 1.16% (2/172) at 9°C and 1.42% (2/141) in the control group (7.5°C). The free larvae showed no, slight and strong movement at 9°C, 12°C and 15°C, respectively, in saline water, and the larvae were present in a coiled state at 9°C and 12°C. The results suggest that temperature plays an important role in the intra-vitam larval migration of A. pegreffii. In addition, the free larval behavior of A. pegreffii in vitro increased with increase in temperature. Therefore, to prevent human anisakiasis caused by the consumption of raw fish, it is important that the temperature of the aquarium must be maintained below 12°C, which is the critical temperature zone.

Black porgy and fat greenling are commercially important fish species due to the continuously increasing demand in Korea. When estimating acoustically the fish length by a fish sizing echo sounder, it is of crucial importance to know the target strength (TS) to length dependence. In relation to these needs, the target strength experiments for live fishes were conducted in an acrylic salt water tank using two split-beam echo sounders operating at 70 and 120kHz. The target strength under well-controlled laboratory conditions was simultaneously measured with the swimming movement by digital video recording (DVR) system and analyzed as a function of fish length (L) and frequency (or wavelength λ). Equations of the form TS-alog (L)+blog (1)+c were derived for their TS-length dependence. The best fit regression of TS on fork length for black porgy was TS=20.62 log (L, m)-0.62 log (λ, m)-30.68 (r2=0.77). The best fit regression of TS on fork length for fat greenling was TS=12.06 log (L, m)-5.85 log (λ, m)-22.15 (r2=0.44).

서해안의 연안성 어종인 쥐노래미는 백령, 대청 근해에서 주요 어종의 하나로 주로 통발에 의해 어획되고 있다. 쥐노래미 어업이 지속적으로 유지되기 위해서, 소형어를 보호하는 효율적인 어구 사용과 현재 정해져 있는 망목크기가 적정한가를 파악하기 위하여 망목선택성 실험을 하였다. 쥐노래미 통발에 대한 망목선택성을 Kitahara의 방법에서 객관성이 있도록 선택성 곡선을 다항식이나 로지스틱 곡선식을 이용하여 구하고, 쥐노래미의 최소성숙체장에 대한 적정망목크기를 구하였다. 통발의 경우, 선택성 곡선(마스터 곡선)을 구할 때 적용한 다항식은 삼중자망에서와는 달리 어체가 큰 부분에서 보정치가 지나치게 작용하여 선택성 곡선을 신뢰할 수 없었고, 로지스틱 곡선이 보다 합리적이었으며, 그 식은 다음과 같았다. s(R) =(equation omitted) 쥐노래미의 최소성숙체장은 21.4㎝로 알려져 있으며, 이 최소성숙체장에 대해 50% 어획될 확률 (L<SUB>50</SUB>)이 되는 망목크기는 37.0㎜이었다. 현재 통발의 망목크기 제한은 35㎜로 규정되어 있는데 쥐노래미의 경우에 다소 작으나 큰 차이는 없는 것 같다.