Characteristics on Growth and Sexual Maturation of an Endangered Fish, Stumpy Bullhead (pseudobagrus Brevicorpus), From Korea by Artificial Rearing

27 Mar Characteristics on Growth and Sexual Maturation of an Endangered Fish, Stumpy Bullhead (pseudobagrus Brevicorpus), From Korea by Artificial Rearing

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Abstract

멸종위기에 처한 꼬치동자개(Pseudobagrus brevicorpus)의 보전과 복원을 위한 기초 자료를 제공하기 위하여 인공사육 환경에서 사육된 종묘에서 친어까지의 성장과 성성숙 특징들을 조사하였다. 부화 후 698일의 인공사육 기간 동안 전장과 체중은 각각 $89.22{pm}10.29mm$와 $70.93{pm}7.68g$로 성장하였고, 전장 (TL)과 체중(BW)의 관계는 $BW=5{times}10^{-5};TL^{2.678}$ ($R^2=0.995$)로 나타났으며, 생존율은 74.2%였다. 암컷과 수컷의 성비는 1 (암컷, 471) : 1 (수컷, 473)이었다. 부화 후 663일째에 암컷의 전장과 체중은 각각 $78.38{pm}0.92;mm$과 $6.38{pm}0.20;g$로 나타나 수컷의 $87.44{pm}1.07mm$와 $8.43{pm}0.31g$에 비해 높았으나, 비만도는 암컷이 수컷에 비해 유의적으로 값을 보였다(P<0.05). 암컷 1마리당 포란수는 평균 734개(508~867개)였고, 난경은 0.04~1.65mm의 범위를 보였다. 인공 사육된 친어는 만 2년이 되던 6월 초순에 인간 융모성 고나도트로핀(human chorionic gonadotropin: HCG)을 주사한 후 1~2일 사이에 산란이 가능하였고, 부화된 개체는 평균 216마리(113~338마리)였다.

English Abstract

The stumpy bullhead (Pseudobagrus brevicorpus) endemic to Korea is one of critically
endangered freshwater fish species. To provide baseline data for its captive breeding and reintroduction
we investigated basal characteristics on its growth and sexual maturation in an artificial
rearing environment. After 698-day rearing the stumpy bullhead grew up to 89.22±10.29 mm in
total length (TL) and 70.93±7.68 g in total body weight (BW)(BW=5×10-5 TL2.678; R2=0.995),
and showed survival rate of 74.2%. The sex ratio was 1 (471 females) : 1 (473 males), and males (TL=
87.44±1.07mm; BW=8.43±0.31 g) showed significantly faster growth than females (TL=78.38
±0.92mm; BW=6.38±0.20 g) after 663-day rearing. However, condition factor of females was
significantly higher than that of males (P<0.05). The number of eggs per female ranged from 508 to 867 (average 734), and their diameters ranged from 0.04 to 1.65 mm. The females which reared about two years in the laboratory condition was able to spawn in the early June after 1~2 days of human chorionic gonadotropin (HCG) injection. The number of hatched fries ranged from 113 to 338 (average 216). The stumpy bullhead (Pseudobagrus brevicorpus) endemic to Korea is one of critically endangered freshwater fish species. To provide baseline data for its captive breeding and reintroduction we investigated basal characteristics on its growth and sexual maturation in an artificial rearing environment. After 698-day rearing the stumpy bullhead grew up to 89.22±10.29 mm in total length (TL) and 70.93±7.68 g in total body weight (BW)(BW=5×10-5 TL2.678; R2=0.995), and showed survival rate of 74.2%. The sex ratio was 1 (471 females) : 1 (473 males), and males (TL= 87.44±1.07mm; BW=8.43±0.31 g) showed significantly faster growth than females (TL=78.38 ±0.92mm; BW=6.38±0.20 g) after 663-day rearing. However, condition factor of females was significantly higher than that of males (P<0.05). The number of eggs per female ranged from 508 to 867 (average 734), and their diameters ranged from 0.04 to 1.65 mm. The females which reared about two years in the laboratory condition was able to spawn in the early June after 1~2 days of human chorionic gonadotropin (HCG) injection. The number of hatched fries ranged from 113 to 338 (average 216).