農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

石斑魚是台灣海水養殖中的高經濟魚類。在過去的二十年，台灣已建立了至少四種石斑魚的人工繁殖技術，然而在和許多種海水魚類相較，石斑魚育苗仍遇到許多困難，如同齡殘食經常造成魚苗的高死亡率，以致於整體的育苗率仍偏低。很多環境因子都被認為會影響殘食的嚴重度及發生率，但僅有少數的研究是針對這些因子的影響，予以設計實驗並加以檢驗。因此，本研究調查一些環境因子，如餵食時間（上午九點和下午三點、上午九點和下午五點、上午七點和下午五點及上午七點和下午三點餵食組等四個時間組合）、餵食頻率（四種頻率：每天餵食一至四次）及遮蔽物（兩種遮蔽物：牡蠣殼及磚塊）等，對點帶石斑魚苗殘食率的影響。實驗均於水族缸中進行。實驗的結果顯示，在這些因子中，以餵食頻率對石斑魚苗殘食率的影響最為顯著（P<0.05），較高的餵食頻率（每天3-4次）在抑制殘食率方面，明顯地優於較低餵食頻率（每天1-2次）組；至於餵食時間及遮蔽物有無，對石斑魚苗殘食率則無顯著之影響。
關鍵詞：殘食、環境因子、點帶石斑、餵食策略、育苗、遮蔽物。

Groupers, Epinephelus spp., are high-value mariculture finfish in Taiwan. In the past two decades, artificial propagation techniques have been established for at least four Epinephelus species. However, massive seed production still encounters many difficulties, particularly with the problem of cannibalism. Many environmental factors are considered to be influencing the extent and rate of cannibalism. However, studies for the impact of these factors on grouper cannibalism are rare. This study used orange-spotted grouper, E. coioides, fry reared in aquariums to investigate the effects of feeding time, feeding frequency and shelter on cannibalism rate. The results indicated that only feeding frequency, had significant changes on the cannibalism rate; higher feeding frequencies (3-4 times daily) showed a significantly decreased cannibalism rate than lower feeding frequencies (1-2 times daily).
Key words: Cannibalism, Environmental factors, Epinephelus coioides, Feeding strategy, Larviculture, Shelter.