한국고유종 줄종개 Cobitis tetralineata의 난발생 및 초기생활사

Egg Development and Early Life History of the Korean Spine Loach, Cobitis tetralineata (Pisces:Cobitidae)

우리나라 고유 담수어류 줄종개 Cobitis tetralineata의 난발생 및 초기생활사를 연구하기 위하여 2013년 6월 섬진강 상류인 전북 순창군 복흥면 정산리에서 족대를 이용하여 친어를 채집하여 실험하였다. 채집된 성숙한 친어는 복강에 Ovaprim을 주사하여 12시간 경과 후 복부압박법으로 채란하고 건식법으로 인공수정 시켰다. 산란된 성숙란은 약한 점착성을 띤회색의 분리침성난으로 난경은 $1.04{\pm}0.03mm$이고 산란수는 $2,646{\pm}916$개였다. 수온 $25^{\circ}C$에서 수정 후 56시간 만에 부화 하였으며, 크기는 전장 $4.6{\pm}0.11mm$이었다. 부화 5일 후에 전장 $6.8{\pm}0.28mm$로 난황이 모두 흡수되어 후기자어로 이행하였으며, 25일 후에는 전장 $9.8{\pm}0.50mm$로 지느러미 기조가 모두 정수로 되어 치어기로 이행하였다. 부화 후 100일 후에는 전장 $34.7{\pm}5.77mm$로 4줄의 Gambetta's zone이 완성되고 외형은 성어와 비교적 유사하였다.

Egg development and early life history of the Korean spine loach, Cobitis tetralineata, were investigated in the present study. Adult fish were sampled using spoon nets at the Seomjin River in Jeongsan-ri, Bokheong-myeon, Sunchang-gun, Jeollanbuk-do, Korea, July 2013. Eggs were obtained after injecting Ovarprim into females. Eggs were then artificially fertilized using the Dry method in the laboratory. Mature eggs were slightly adhesive and transparent with grey coloring, and measured $1.04{\pm}0.03mm$ ($mean{\pm}SD$) in diameter. Hatching of the embryo occurred approximately 56 hours after fertilization at $25^{\circ}C$ of water temperature, and the average size of newly hatched larvae was about $4.6{\pm}0.11mm$ in total length. At fifth day after hatching, the larval full length reached $6.8{\pm}0.28mm$ on average and their yolk sac had been completely absorbed. At 17th day after hatching, larva entered the juvenile stage and reached $9.8{\pm}0.50mm$ in total length. At 100th day after hatching, the formation of Gambetta's zone of four line was complete and juveniles were similar in general appearance to adults, and they averaged $34.7{\pm}5.77mm$ in total length.