Pacific herring Clupea pallasii eggs were attached to the gill net in Korean coastal waters off Busan. To conservation and management the eggs attached to the gill net, we followed the natural hatching in coastal waters from five days after fertilization to the hatching finished, where the temperature was 9°C. The diameter of fertilized eggs was 1.24–1.55 mm (n= 50), and had a segmented pale yellow yolk, no oil globule. Natural hatching had started by 10 days after fertilization. Mass hatching occurred around 11–12 days after fertilization, most of eggs separated from the gill net. Therefore, when the Pacific herring eggs attached in gill net, should be natural hatching–induced in coastal waters during 12–14 days.

• 지환성 | Hwan–Sung JI
• 이동우 | Dong Woo LEE
• 최정화 | Jung Hwa CHOI
• 최광호(국립수산과학원 자원관리과) | Kwang Ho CHOI (Fisheries Resources Management Division, National Fisheries Research and Development Institute, Busan 619–705, Korea) Corresponding author