菊池氏細鯽之飼料開發

Abstract

菊池氏細鯽Aphyocypris kikuchii (Oshima, 1919)為台灣特有種，主要分布範圍為台灣東部三縣，屬於小型初級淡水魚類，主要棲息於河川湖泊水流較緩之水域，尤其是水生植物繁生之池沼及農田排水溝，黃昏清晨間在水面跳躍，以捕食成群飛舞之搖蚊，平時以藻類和掉落水中的昆蟲為食，食性屬雜食性。當地大部分將此魚油炸後食用，或將其作為海釣時的釣餌，此外因為其體態優美，體色呈現金黃色，故亦可當觀賞魚養殖。近年來由於棲地的破壞與環境的污染，使其族群分布範圍與數量逐漸縮減，目前已有此魚種的人工繁養殖及魚苗發育的相關研究，故開發其飼料，將有助於此魚種的量產或保育復育工作。 實驗一：於各組含有30％魚粉(Fish meal)之飼料中，添加大豆粉(Soybean meal) 0％∼40％共五個添加量，糊精(Dextrin)的添加量則互換為40％∼0％五個添加量，分為S0D4、S1D3、S2D2、S3D1及S4D0等五組飼料，探討此魚種對蛋白質和碳水化合物之間的利用關係。由42天之飼養結果顯示，以S4D0組增重率165％及飼料效率60％為最佳，此組飼料之蛋白質含量約40％，由此顯示菊池氏細鯽對於蛋白質的利用率較碳水化合物為佳。 實驗二：對照組飼料(FM30)蛋白質來源為30％魚粉及40％大豆粉，實驗組飼料中的魚粉添加量分別降為25％、15％及0％，另添加大豆粉及玉米蛋白(Corn protein)等植物性蛋白原料，用以取代動物性蛋白在飼料中的添加量，調配出FM30、FM25、FM15及FM 0 等四組飼料。由42天之飼養結果顯示，以FM25為最佳，其增重率156％及飼料效率56％。低魚粉組飼料與魚粉添加量較多的組別之間並無顯著差異，顯示此魚種對不同的植物性蛋白之利用率，皆有不錯的效果。

The Kikuchi minnow (Aphyocypris kikuchii), is a small native freshwater fish that used to be found in streams, ponds and lakes of eastern Taiwan. They often swim in school between aquatic plants and boulders in the water, where they forage for small insects or benthic algae. It prefers the habitats with slow water flow that is rich in aquatic plants for cover. In recent years, due to environmental deterioration that is caused by destruction of habitats and water pollution, their population distribution in the wild has been greatly affected. Development of artificial diet will not only provide the material for the aquaculture but also for the conservation of A. kikuchii. Two experiments were conducted to study the optimum dietary protein level, and the growth performance in low fish meal diets. Experiment I：Five diets contain five protein levels ranging from 25％ to 40％, and carbohydrate levels ranging from 35％ to 55％, were fed to triplicate groups of Kikuchi minnow (initial body weight 0.20 ± 0.03 g fish-1) for 6 weeks. The highest weight gain (WG) and feed efficiency (FCR) were recorded in fish fed Diet S4D0, which contained 40％ soybean meal (SBM). According to the results, utilization of protein is better than carbohydrate on Kikuchi minnow. Experiment II：Four isonitrogenous (crude protein 38％) and isolipid (crude lipid 8％) were formulated to feed Kikuchi minnow (initial body weight 0.39 ± 0.05 g fish-1) for 6 weeks. Diet FM30 (control) contains the highest percentage of fish meal (FM), up to 30％. In the other three diets (FM25, FM15 and FM0), FM protein was replaced by SBM and corn protein (CP) as alternative plant protein resources. The highest WG and FCR were recorded in fish fed diet FM25, which contained 55％ plant protein. Results were showed that Kikuchi minnow also has good utilization of different plant protein supplements.