The purpose of this study is to determine the effects of vibration on primary (e.g. plasma cortisol), secondary (e.g. plasma glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), Na+, K+ and Cl- and tertiary (e.g. mortality) stress responses in cultured eel, Anguilla japonica. For this purpose, three groups (including one control group and two stress groups) were set up. The control group was made exposed to vibration corresponding to 48 decibel (dB, V) (produced using electric vibrators) for 15 minutes per hour every day, and the two stress groups was made exposed to vibration corresponding to 58 and 68 dB (V) (produced using the same electric vibrators), equally, for 15 minutes per hour every day. Blood was sampled at day 0 (before starting vibration stress tests, BS), and days 1, 3, 5, 7, 9 and 11 (after starting vibration stress tests). As a result, plasma cortisol showed trend to continuously rise by consecutive stress from 4.1±0.1 ng/ml in BS. In 48 dB group (control), cortisol showed the highest level with 7.6±0.9 ng/ml after 7 days (p <0.05), but at 9 and 11 days was not significantly compared with BS level. In 58 dB group, the cortisol showed the highest level with 43.1±4.8 ng/ml after 1st day. Cortisol of 68 dB group increased significantly during the experimental period (14.4±2.3~32.0± 5.7 ng/ml) (p<0.05). In 58, and 68 dB groups during the experimental period differed significantly compared to 48 group (p <0.05). Glucose in 48 dB were increased from 42.0 ±5.7 (BS) to 52.5±2.1 (1 day), the level was not significantly from 1 to 11 days. Glucose in 58 and 68 dB groups was increased significantly than BS during experimental period (p <0.05). K+ in 68 dB increased significantly (p <0.05) from 2.3±0.2 mE/ql (BS) to 3.3± 0.5 mE/ql at 5 days. In 48 and 58 dB groups during the experimental period differed significantly (p <0.05). Na+ and Cl- levels were not differed significantly during the experimental period. AST and ALT in 58 and 68 dB groups showed trend to continuously rise by consecutive stress. At 7 and 9 days in AST, between 48, 58 and 68 dB groups differed significantly (p <0.05). In 48, 58 and 68 dB groups at 1 day, blood hematocrit increased significantly higher than BS. The 11 days after vibration stress, the mortality in 48, 58 and 68 dB groups was 1.1, 5.1 and 5.8%, respectively. The present results have shown that A. japonica exhibited ''typical'' physiological responses when exposed to chronic vibration stress. These data suggested that chronic vibration stress caused substantial stress in the fish; especially the persisting elevated plasma AST and ALT levels observed would be expected to adverse effect. In conclusion, chronic vibration stress could greatly affects the hematological characteristics in A. japonica.

Shortfin eel (Anguilla bicolor pacifica) is a species of commercial importance and its production is greatly affected due to the infection by Heterosporis anguillarum. In this study, we evaluated the effect of H. anguillarum infection on the growth of Shortfin eel. A disease that trunk muscle of cultured shortfin eel, Anguilla bicolor pacifica, were irregular and resulted in death, breakout of the commercial eel culture farm. We observed that the trunk muscle of infected eels were irregular and represented white or yellowish externally. Histopathologically, a great numbers of large or small spores and sporophorocysts were also observed in degenerated muscle layer. The cloning of specific gene of H. anguillarum, encoding small subunit ribosomal RNA (SSU-rRNA) was amplified by the polymerase chain reaction(PCR) from the muscle lesion of diseased eel. The size of clone gene is well matched with the size of small subunit ribosomal RNA of H. anguillarum and thus confirming the infection by H. anguillarum.

수산용 항균제로 널리 사용되고 있는 옥소린산의 잔류량을 전북지역에서 시판중인 뱀장어 근육조직에서 측정하였다. 후배부 근육중의 옥소린산 잔류량은 시료에 따라 많은 차이가 있었으며 2%의 시료에서는 검출되지 않았다. 옥소린산이 검출된 시료중 16%에서는 그 농도가 0.1 ppm 이상이었다. 중요 장기중의 옥소린산 농도는 신장>간장>혈장>근육의 순이었다. 근육중의 옥소린산은 10분 가열에 의해 거의 감소되지 않았으며 30분 가열에 의해서는 원래 농도의 50% 수준으로 감소하였으나 30분 가열 후의 시료는 심하게 탄화되었다. 고용량의 옥소린산을 실험실적으로 뱀장어에 투여하여 얻은 근육중의 농도나 수용액중의 옥소린산이 가열에 의해 파괴되는 경향을 검토함으로써 옥소린산의 열안정성이 확인되었다. 이 연구 결과는 뱀장어 소비자를 옥소린산 섭취로부터 보호할 수 있는 규제의 강화가 필요함을 시사한다.

겨울철 사육조건이 양식산 뱀장어 Anguilla japonica의 인위적인 성성숙 유도 및 번식에 미치는 영향을 조사하였다. 봄철 salmon pituitary extracts(SPE)을 이용하여 성성숙 유도 예정인 양식산 암컷 뱀장어 친어를 8주의 겨울철 사육기간 동안, 4개의 사육환경(해수저온, ; 해수고온, ; 담수저온, ; 담수고온, )에 각각 순치하여 사육하였다. 그 후 각각의 실험구의 뱀장어를 해수 로 이동하여 SPE를 매주 1회 8주 동안