台灣東北部藍帶蓋刺魚生殖模式之研究

Reproductive Mode of Blue-striped Angelfish Chaetodontoplus septentrionalis in the Northeastern Taiwan

陳冠宇(Kuan-Yu Chen)

指導教授 ： 曾萬年

國立臺灣大學/生命科學院/漁業科學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.00821

摘要

藍帶蓋刺魚Chaetodontoplus septentrionalis （Temminck & Schlegel 1844）是一種珊瑚礁魚類，其分佈海域，從南起香港、經台灣，北至日本南部。它們是一種倍受重視海水觀賞魚類，並且在水族養殖上擁有商業潛力。基礎生殖生物學的知識對於人工繁殖來說相當重要，為了瞭解藍帶蓋刺魚產卵週期與行為等生殖生物學，本研究分別利用生殖腺成熟度指數（Gonadosomatic index，GSI）與組織切片觀察法來推測其生殖腺的季節性變化以及卵細胞的發育過程。樣本是每月委託宜蘭縣南方澳漁民採集而得，從2003年1月至2004年1月連續一年，總共收集到164隻成魚體色的標本。標本的體長範圍在143.1~215.4 mm TL之間，性別比例中雄魚多於雌魚（♂:♀＝91:64）。雄魚的平均體長為180.7±13.9 mm TL，雌魚為172.8±12.0 mm TL，兩者之平均體長無顯著性差異（P ＞0.05）。雌魚的平均GSI値從晚春到夏天（五月~七月）有較高的値；而雄魚的平均GSI則比雌魚早上升晚下降（三月~八月）。由卵巢的組織切片發現雌魚在生殖季節卵巢同時存在不同發育階段的卵細胞，顯示藍帶蓋刺魚應屬於分批產卵型（Partial spawner）。水溫可能是影響藍帶蓋刺魚生殖活動的主要因子，熱帶地區的魚類通常為終年產卵型，然而，位於亞熱帶地區的台灣東北部，因受到東北季風的影響，冬天的水溫會低於20℃，這可能是造成藍帶蓋刺魚只在夏天產卵的原因。

關鍵字

蓋刺魚 ； 生殖生物學 ； 生殖腺成熟度指數

並列摘要

Blue-stripe angelfish Chaetodontoplus septentrionalis (Temminck & Schlegel 1844) which is a coral reef fish distributed from Hong Kong, through Taiwan to southern Japan. It is an important marine ornamental fish and quite potential in the aquaculture industry. However, the fundamental knowledge of reproductive biology for artificial propagation of this species is rarely described. To understand the spawning periodicity, the gonadosomatic index (GSI) and histology of the gonad were examined based on the 164 adult-color individuals collected from the reef zone of I-Lan in the northeastern Taiwan during the period from January 2003 to January 2004. The total length of the specimens ranged from 143.1 ~ 215.4mm. Sex ratio of the fish was dominated by males (♂:♀＝91:64). The mean (±SD) total length was not significantly different (P＞0.05) between male (180.7±13.9mm) and female (172.8±12.0mm). GSI of the females significantly increased from late spring to mid summer (May ~ July), but GSI of the males increased early and declined late (March ~ August). The histology of the ovary indicated that this fish is a partial spawner with synchronous occurrence of previtellogenic and vitellogenic oocytes and secondary oocytes during spawning season. Temperature is probably the principal factor in determining the spawning cycle of the coral reef fish, which leads to the reef fishes in the tropical area spawn throughout the year. However, the coasted waters in subtropical Taiwan is influenced by the prevailing northeast trade wind and the temperature decreased to lower than 20℃ in the water that leads to blue stripe angelfish spawn only in the summer.

並列關鍵字

angelfish ； reproductive biology ； gonadosomatic index

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