본 연구는 우리나라에 서식하는 쌀미꾸리(Lefua costata)의 산란기 특징 및 초기발달과정을 밝히고자 2018년 1월부터 12월까지 강원도 강릉시 옥계면 주수천 일대에서 수행되었다. 산란기는 생식소성숙도 변화와 당년생 치어 출현, 난경의 분포 등을 고려하여 5월부터 8월로 추정되었고, 다회 산란형이었다. 성비는 암컷 1,117개체, 수컷 879개체가 채집되어 1 : 0.79였다. 산란기 동안 확인된 난경은 0.24~0.93 ㎜로 성숙란과 미성숙란이 함께 확인되었다. 성숙란의 크기는 0.71±0.02 ㎜, 포란수는 평균 1,786±818 (n=31)개였다. 난 발달과정을 관찰한 결과 수정란은 점착성을 띤 회색의 분리침성난으로 난경은 0.76±0.03 ㎜였다. 25℃에서 수정 후 34시간(50%) 후에 부화하였으며, 부화직후 전기자 어 크기는 전장 2.7±0.11 ㎜였다. 부화 후 4일에는 전장 4.5±0.16 ㎜로 난황이 모두 흡수되어 후기자어로 이행하였다. 부화 후 20일에는 전장 11.5±0.67 ㎜로 모든 지느러미 기조가 정수가 되어 치어기로 이행하였다. 부화 후 100일에는 전장 49.8±2.60 ㎜로 외형과 체측무늬는 성어와 비교적 유사하였다.

This study was conducted to elucidate spawning period characteristics and early life development of eight barbel loach, Lefua costata (Balitoridae) at the Jusucheon stream, Okgye-myeon, Gangneung-si, Gangwon-do, Korea between January and December in 2018. The spawning period was estimated to be from May to August, considering the change in the gonad-somatic index, the appearance of young fry, and frequency distribution in egg diameter. It was a multi-spawning type. The gender ratio was 1:0.79 with 1,117 females and 879 males collected. The egg size was 0.24-0.93 ㎜, with mature and immature eggs found during the spawning period. The size of mature eggs was 0.71±0.02 ㎜, and the average number of fecundity was 1,786±818 (n=31). Observation of the egg development showed that the fertilized eggs were the sticky, gray, segregated, and demersal type with 0.76±0.03 ㎜ in diameter. The hatching of the embryos began at about 34 hours (hatching rate 50%) after fertilization underwater temperature of 25℃. The average length of the newly hatched pre-larvae was 2.7±0.11 ㎜. The average length of pre-larvae at 4 days after hatching was 4.5±0.16 ㎜, and the yolk sac was completely absorbed and entered the post-larvae stage. At 20 days after hatching, the average length of post-larvae was 11.5±0.67 ㎜, and their fin rays were formed before they transitioned to the juvenile stage. At 100 days after hatching, the average length reached 49.8±2.60 ㎜, and the appearance and the lateral sideband patterns were similar to those of the adult fish.

요 약
ABSTRACT
서 론
연구방법
    1. 채집 및 산란기 특징
    2. 초기발달과정
결 과
    1. 성비
    2. 생식소 성숙 및 산란기
    3. 난경과 포란수
    4. 초기발달과정
    5. 자어와 치어의 발달
고 찰
REFERENCES

• 김형수(국립수산과학원 첨단양식실증센터) | Hyeong-Su Kim (Advanced Aquaculture Research Center, National Institute of Fisheries Science)
• 한미숙(고수생태연구소) | Mee-Sook Han (Kosoo Biology institute)
• 고명훈(고수생태연구소) | Myeong-Hun Ko (Kosoo Biology institute) Corresponding author