http://scholars.ntou.edu.tw/handle/123456789/14482
標題: | Selectivity and accessibility of prey in captive juvenile red drum, Sciaenops ocellatus Linnaeus | 其他標題: | 養殖環境下之黑斑紅鱸稚魚對於生物餌料之選擇性與接近性 | 作者: | 廖一久 張怡穎(Emily Y. Chang) |
關鍵字: | 選擇指數;選擇性;嗜好性;接近性;餌料體型;Electivity index;Selectivity;Preference;Accessibility;Prey size | 公開日期: | 1-三月-2002 | 出版社: | Journal of the Fisheries Society of Taiwan | 卷: | 29 | 期: | 1 | 起(迄)頁: | pp.21-29 | 摘要: | 本研究探討黑斑紅鱸稚魚對於活餌的選擇性(selectivity)與接近性(accessibility),採用之活餌種類包括小吳郭魚(Oreochromis aureus×O. niloticus)、五鬚蝦(Palaemon macrodactylus)、海(青)虫(Neries virens)、及無齒螳臂蟹(Chiromantes dehaani)共四種。四種活餌以相同數目同時出現,在進食一小時後,收集未被捕食之活餌,以估計各活餌之被捕食量;另外也取出各實驗魚,測量其體長與體重,並解剖觀察其胃容物,以確定其捕食餌料之種類與數量。利用Ivlev選擇指數(Electivity index),決定各捕食者對不同活餌之好惡程度,稚魚之大小與各餌料生物之選擇指數間的相關性可因而建立。結果發現黑斑紅鱸稚魚體型較大者偏向食魚,體型較小者則偏向食海虫與蝦;此外,四種餌料中,螃蟹是稚魚最不喜愛之餌料。由捕食者體型與其胃中餌料之體型相關性看來,體型較大之稚魚所捕食之餌料體型範圍也較寬。各活餌之接近性可經由比較稚魚對活餌與死餌之選擇性而求得,結果顯示蝦被選擇的原因可能在於其接近性最高,海虫之接近性雖然較蝦為低,但卻是四種餌料中稚魚最嗜食的一種,而小吳郭魚之接近性對較大之稚魚而言比較小之稚魚為高;另外,因螃蟹之接近性最低,故最不受稚魚的喜愛。本研究闡明黑斑紅鱸稚魚對餌料之選擇,乃根據其本身之嗜好、餌料之體型大小、以及活餌之接近性而定。 Selective feeding on live prey was studied in juvenile red drum (25~37 cm in total length). Live prey selected included young fish (the hybrid tilapia Oreochromis aureus×O.niloticus), shrimp (Palaemon macrodactylus), polychaete ragworm (Neries virens), and crab (Chiromantes dehaani). They were presented simultaneously in equal number to the red drum. After feeding for one hour, prey that was not consumed was collected, counted and weighed. The red drum were individually retrieved and dissected for examination of stomach contents. Iv lev's electivity index (E) was used to determine the degree of preference to or avoidance of different prey by predators. Relationships were established between red drum size and electivity index for different prey. Results suggest that the selective ability of juvenile red drum might vary with its size. Larger red drum became more piscivorous. Smaller red drum preferred polychaete and shrimp over fish. Crab was the least favorable prey among all four items. A size profile, derived from the size of predators and the size of prey in the stomach, showed that the size range of prey consumed by the red drum increased with the size of the predator. Accessibility of the prey was deduced from a comparison of prey selection using ”dead” and ”live” preys. The result indicates that shrimp is favored by smaller red drum because it is most accessible of the four prey offered. Polychaete ragworm was less accessible than the shrimp, but it was most preferred by the red drum among four prey. Fish is more accessible to larger than smaller red drum. Crab is most avoided by red drum juveniles because it is most difficult to access. This study demonstrated that juvenile red drum selected prey according to its inherent preference, and prey size and accessibility. |
URI: | http://ntour.ntou.edu.tw:8080/ir/handle/987654321/45052 http://scholars.ntou.edu.tw/handle/123456789/14482 |
DOI: | 10.29822/JFST.200203.0002 |
顯示於: | 海洋中心 |
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