| 英文摘要 |
Swamp eel (Anguilla marmorata Quoy et Gaimard, 1824), a catadromous migration fish, was once a conservation species in Taiwan. Under the protection policy and promotion activity, the resources of wild swamp eel are now recovered and overpassed that of A. japonica. Swamp eel larvae are abundant with reasonable price here in Taiwan, hence serve as potential culture species. The development of culture technology offered opportunities for conventional eel culture and might become an emerged aquaculture species. This study will start with keeping wild swamp eel larvae which was identified as A. marmorata following the ratio of the distance between the verticals from beginning of dorsal fin to anus to total length, to assure productive procedure and feeding technology. To co-operate the habitual behavior and the flavor to the feed, we tamed the eel with Tubifex sp. andartificial diet and the investigation of cultivating density was carried. The results indicated that after 4 months, the feed efficiency and weight gain were the best at 200 eels/m2 in the period of 0.5 to 2 g/eel, and the mouth of the eels was big enough to eat the commercial floating diet at 0.8 mm when their weight over 1.6 g in the experiment of feeding different kind of diets. The optimal temperature of A. marmorate elvers was 30℃, and the oxygen consumption, excretion rate of ammonia-N and urea-N, accumulation of ammonia-N and urea-N, lethal oxygen of elver, were increased with increase of the temperature, but its lethal time was decreased with increase of the temperature under 30℃. A. marmorate elvers sudden changed to the combination of different salinity and different water temperature resulting in the increased of oxygen consumptive rate of A. marmorate elvers with temperature increased, but decreased with salinity increased. The lethal oxygen of A. marmorate elver was increased with the increase of water temperature and lethal time was decreased with water temperature increased, however, both of lethal oxygen and lethal time did not relate to the salinity. A. marmorate elvers after sudden changed to different water temperature showed that hemolymph excretion ration of ammonia-N and urea-N at same temperature was increased first and decreased later. While the accumulation of ammonia-N and urea-N were increased with the increase of follow time. At the same time, the excretion rate of ammonia-N and urea-N, accumulation of ammonia-N and urea-N were increased with the increase of temperature. Because of the late growing at initial phase (to grow up at 2-3 eel/kg for 3 years) and the size for selling (over 1.5 kg/eel), the cultivation should be separated, and chosen the right phase depended on the installations and financial capability of the farmers. The cultivating density should be decreased following the growth rate, and the best density is at 2-3 eel/kg to 2-5 kg/eel at 2000-3000 eels per 分. At the latter phase of cultivation, it is proper to feed once two days for preventing the disease outbreak, and to manage the water resource could follow the way of cultivating A. japonica. |