한수지 6(), 7-8, Original Article Kor J Fish Aquat Sci 6(),7-8, 양식멍게 (Halocynthia roretzi) 의물렁증발생에미치는절식의영향 김동욱ㆍ박정준ㆍ양성진 김창훈 ㆍ신윤경 * 국립수산과학원전략양식연구소양식관리과, 부경대학교해양바이오신소재학과 Starvation Effects on Occurrence of Tunic Softness Syndrome in Sea Squirt Halocynthia roretzi Dong Wook Kim, Jung Jun Park, Sung Jin Yang, Chang Hoon Kim and Yun Kyung Shin* Aquaculture Management Division, Aquaculture Research Institute, National Fisheries Research & Department Institude, Busan 69-9, Korea Department of Marine Bio-materials and Aquaculture, Pukyung National University, Busan 68-77, Korea We examined the effect of starvation on the occurrence of tunic softness to determine the cause of mass mortality of cultured Halocynthia roretzi (Drasche) in the Tongyeong region, Korea. In terms of the survival rate of H. roretzi and the occurrence rate of tunic softness, H. roretzi starved for days at water temperatures of 8,, and C ±. C (room temperature of C ± C) did not exhibit tunic softness at water temperatures of either or C. for morphological changes, although the tunic of H. roretzi was shrunken and became visibly smaller with a darkening color in all experimental groups, as compared to the state prior to starvation, its tunics bulbs continuously. The ratio of concentrations and protein contents for each of the tunic sections were lower in the starved group. Our results indicate that tunic softness is not related to feeding deficiency, as no histopathological symptoms were apparent in the digestive gland or tunic of H. roretzi due to starvation. Key words: Halocynthia roretzi, Sea squirt, Tunic softness syndrome,, Histopathologic symptom 서 론 (Hong, 6), ( ),,,,,.,. 7,6, 6, 9, 7,-8, (KOSIS, ), 7.6%, 6 68.%, 8 8.% 9 67.%, (NEMA, ). (Hur, 9). Article history; Received March ; Revised July ; Accepted October *Corresponding author: Tel: +8.. 7. Fax: +8.. 7. 9 E-mail address: yunkshin@korea.kr (Shin et al., ; Kim et al., )., (Hirai, 9, 96), (Yoo et al., 99), (Jang, 979), (Yoo et al., 988). (Kim et al., ),, (Shin et al., 7; Na et al., 99; Hong et al., ) (Shin et al., ). (Jiang et al., 8) (Ryland, 99) (Armsworthy et al., ). Halocynthia roretzi (Kumagai et al.,, ), Kor J Fish Aquat Sci 6() 7-8, October http://dx.doi.org/.67/kfas..7 pissn:7-8, eissn:87-88 c The Korean Society of Fishereis and Aquatic Science. All rights reserved 7
76 김동욱ㆍ박정준ㆍ양성진ㆍ김창훈ㆍ신윤경 (Choi et al., 6), (shin et al., ), (Kim et al., ).,, (Bohle, 97; Widdows, 98),,.... (Clemmesen, 99, 99), (Clemmesen, 99, 99), (Chang et al., 98; Jung et al., ). (Shin et al., ) (Kim et al., ).,. 실험재료 재료및방법 (Fig. ), m..,.. psu, 7.7. mg/l., 7. 7.8 mm,.8 6.8 mm, 7.69 6. g. -,. 실험방법 Korea Tong Yeong 8 Yeongun-ri 8 Dundeck-myeon Hansan-Myeon Fig.. of sea squirt Halocynthia roretzi. 8 8.,.,. (,. ),.. 7.7. mg/l.,.. (ø µm).,.,,,.. (,, ),. -7 (8 ), (TE-SDS µl), (, ) 9 mm (Fluoroskan Ascent FL), µl se. vernier calipers.,,,.
Hansan-Myeon 8 8 멍게 물렁증 발생에 미치는 절식의 영향 77 과 Dundeck-myeon Korea 생존율 및 물렁증 발생률 Dundeck-myeon 수온 8±., ±., ± 및 대조구(실온)에서 일 Tong Yeong Korea 간 절식시킨 멍게의 생존율과 물렁증 발생률을 Fig. 와 Fig. 에 나타내었다. 수온 8±. 와 ±. 에서 생존율 Tong Yeong 은 %였으며Yeongun-ri, 수온 ±. 에서는 노출 일째부터 8 폐 사가 발생하기 시작하여 노출 일째 생존율은 %를 나타내 일째 었다(Fig. ). 반면 먹이를 공급한 대조구에서는 노출 8 Yeongun-ri 생존율이 급격히 감소하기 시작하여 일째 모두 폐사하였다 일째 대조구에 (Fig. ). 절식에 따른 물렁증 발생률은 노출 Hansan-Myeon 서는 %, 수온 ±. 에서 %를 나타내었으며, 수온 8 ±. 에서는 물렁증 8±. 와 8 발생이 관찰되지 않았다. Survival rate (%) 결 형태학적 변화 8 물렁증이 주로 발생하는 수온 8,, ±. 및 대조 6 구(±. )에서 일간 절식시키는 동안 멍게의 형태적인 변화를 Fig. 에 나타내었다. 먹이를 공급한 대조구에서는 멍게 C 뚜렷한 형태적인 변화가 관찰되지 않았다. 및 피낭색의 의 피낭 C 그러나 절식시킨 모든 시험구에서는 피낭이 수축되어 쪼그라들 진한붉은 색으로 변하는 것이 어 크기가 작아졌으며, 피낭색은 (Day)실험 기간 동안 구근이 관찰되었다. 그러나 절식에도Time 불구하고 계속 자라는 것이 관찰되었다. 농도 변화 Occurrence rate of tunic softness syndrome (%) Bouin 용액에 시간 동안 고정하여 파라핀절편법으로 µm 두께로 연속절편 후 Mayer's hematoxylin-eosin (H-E) 염색과 Alcian blue-periodic acid and Schiff's solution (AB-PAS, ph.) 반응을 실시하였다. 8 Hansan-Myeon Survival Survival rate (%) rate (%) 조직학적 반응 8 8 C멍게의 각 부위별 농도 및 단백 일간 절식시킨 C 변화를 조사하였다 질 함량 6 (Fig. ). 농도비는 아가 미와 간췌장에서 수온 8±. 높았으나 단백질 함량은 낮게 나타났다. 소화기능과 관련된 간췌장에서는 수온 ±. 에 서 단백질 함량이 가장 높았으나, 그 외의 수온에서는 유사한 값 을 나타내었다. 각 실험수조에서 대조구와 일 동안 절식시킨 멍게의 새낭, 8 group ±. C 6 8 6 C C C 8±. C C Fig.. Survival rate of the seasquirt Halocynthia roretziduring starvation under different water temperatures. ±. C C C 6 8 C 6 C ±. C group ±. C Fig.. Occurrence rate of tunicsoftness syndrome of the sea squirt Halocynthia roretzi during starvation under different water tem group ±. C peratures. 8±. C Fig.. Morphological characteristics of the sea squirt Halocynthia roretzi after starvation period ( days). Gill A/ nt (µg/mg) Occurrence Occurrence rate of tunic rate of tunic softnesssoftness syndrome syndrome (%) (%) 8
78 김동욱ㆍ박정준ㆍ양성진ㆍ김창훈ㆍ신윤경 Gill Gill Protein 6 Hepatopancreas 8 6 8 7 6 Hepatopancreas Mantle Control C C Fig.. Changes in organ ratio of the sea squirt Halocynthia roretzi at different culture temperatures. Fig. 7-. Fig. 7. (papillae),., (Fig. 7A). (digestive tubule) (blind ampulla). (microvilli), (Fig. 7B). (cuticle), (matrix),. (Fig. 7C). 6 8 Control C C 8. (Fig. 8A). (Fig. 8B). (Fig. 9, ). 고 Mantle Fig. 6. Changes of the protein concentration in different organ of the sea squirt Halocynthia roretzi under different water temperatures. 찰 (Chang et al., 98; Hong et al., ), (Na et al., 99) (Hong et al., ). 97, (Chang et al., 98). 99
멍게 물렁증 발생에 미치는 절식의 영향 79 Fig. 8. Histopathological feature of stigmata in sea squirt Halocynthia roretzi by the effect of starvation. A: 8±., showing the hypertrophy of epithelial cells (arrowhead). B: ±., showing the hypertrophy of epithelial cells (black arrowhead), necrotic epithelial cells (white arrowhead). Fig. 9. Histopathological feature of digestive gland in sea squirt Halocynthia roretzi by the effect of starvation. A: 8±.. B: ±.. Fig.. Histopathological feature of tunic in sea squirt Halocynthia roretzi by the effect of starvation. A: 8±.. B: ±.. Fig. 7. Histological characteristics of sea squirt Halocynthia roretzi. A: Stigmata, B: Digestive gland, C: Tunic. Ba, blind ampulla; C, cilia; Cu, cuticle; Dt, digestive tubule; El, epithalial layer; Lhs, longitudinal hemolymph sinus; M, matrix; P, papillae. 년대 후반부터 발생하고 있는 멍게의 폐사증상은 피낭이 연화 되는 물렁증 현상으로서 주로 저수온기인 월에서 이듬해 6월 까지 고수온기 이전에 발생하고 있으며 최근 원인체는 편모충 (Shin et al., ) 및 세균에서 분비되는 대사물질(Kim et al., )으로 외부 감염에 의한 증상으로 보고되고 있어 양식장 환 경의 중요성이 강조되고 있다. 또한 Moon at al. ()에 의하 면 물렁증은 주로 먹이생물 발생량이 높고 생육상태가 양호한 내만 양식장에서 많이 발생하는 것으로 보아 단일의 물리환경 적인 요인으로 보기 어렵다고 추정하고 있어 물렁증 발생과 먹 이부족간의 관계는 매우 모호하다. 수서생물의 생리적 상태는 그들의 영양조건 및 영양 섭취상태 에 달려있다. 그러나 양호한 생리적 상태를 유지하고 개선하기 위한 요인으로서 영양의 중요성을 간과하기 쉽다. 물렁증 발생률이 높은 수온 8, 및 에서 먹이를 공 급하지 않은 그룹과 실온( )에서 먹이를 공급하며 사육한 대조구에서 멍게의 물렁증 발생을 관찰한 결과, 절식에 따른 물 렁증 발생률은 수온 에서 노출 일째 %를 나타내었으 며, 수온 8 와 에서는 물렁증 발생이 관찰되지 않았으며, 절식기간이 길어질수록 피낭이 수축되며 색깔이 짙어지는 것
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