파상회전원판을 사용한 뱀장어사육과 질병대책

Evaluation of A Revolving Plate-Type Biofilter for Use in Recirculating Eel Culture System and Control of Fish Diseases

질병치료용으로 개발한 파상회전원판의 순환여과 장치를 사용하여 199일만에 뱀장어를 3kg에서 815.6kg으로 성장시킬 수 있었다. 사육수를 정화하기 위한 생물막의 표면적이 $1,127m^2$였는데 파상회전원판의 표면적이 $800m^2$였고, 수중에 침적된 PVC 파판의 표면적은 $327m^2$였다. 이 장치는 오물이 고이지 않으므로 Trichodina 충과 Costia 충의 치료가 용이하였다.

The main purpose of this study is to evaluate a revolving plate-type biofilter system for mass culture of eels (Anguilla japonica) based on the experimental rearing for 199 days. Water quality, growth efficiency of fish and effects of fish disease control were critically evaluated. The experiment was conducted in two different units, each unit consisting of a cement tank containing $20m^3$ of water. In unit A, a biofilter which includes 400 rotating undulated P. V. C. plates being 70 cm in diameter which rotates at 6 rpm and also 400 undulated P. V. C. plates fixed in the settling chamber of an area of $66{\times}62cm$. Water was continuously passed through the filter at a rate of 260 l/min., and supplemental water was added to the fish tank at a rate of $4m^3$ a day. In unit B, the biofilter has 400 P. V. C. plates being $66{\times}62cm$ each was installed in the settling tank. The results gained from the experimental rearing for 199 days from April 21, 1984 to November 5, 1984 are as follows. In the growth experiment, the weight of fish in unit A increased from 3.0 kg to 815.6 kg, while in unit B, from 3.0kg to 416.0kg. During the period of the experiment, in the both units the fish grew at an acceptable rate at the temperature at which they were held. Observing every aspect of eel culture, including growth rate, disease control and water quality, unit A appears to have adventages over unit B, which makes it particuraly attractive in intensive recirculating fish culture system. It was further observed that certain parasites such as Trichodina sp. and Costia sp. could easily be controled by appling 4 ppm of $KMNO_4$.