哈盆溪臺灣馬口魚（Zacco barbata）之生殖生態

The Study on the Reproductive Ecology of Zacco barbata in Ha-Pen Creek

顏俊雄(June-Hsiung Yan) ； 呂光洋(Kuang-Yang Lue) ； 陳永樹(Yung-Shu Chen) ； 鄭振寬(Jenn-Kuan Jeng)

《師大生物學報》 30卷2期 (1995/12) Pp. 69-81

https://doi.org/10.29812/BBNTNU.199512.0002

摘要

本研究從1992年2月至1993年4月，探討哈盆溪臺灣馬口魚（Zacco barbata）其族群結構、兩性差異及生殖週期。經過一年多在哈盆溪以電魚法所捕獲的魚隻發現，臺灣馬口魚的雌雄比例與1：1並無顯著差異。每個月所捕獲的臺灣馬口魚可由第二性徵分辨其性別，第二性徵包括頭部及臀鰭的追星與體側的婚姻色。兩性體型較大的個體其頭部的追星及體側的婚姻色終年可見，雄魚比雌魚明顯。只有在生殖季時才能在成熟雄魚的臀鰭上發現追星，雌魚則終年皆未發現。由每個月卵徑頻度分布、成熟度指標（GSI, gonadosomatic index），及生殖腺發育狀態發現，1992年哈盆溪的臺灣馬口魚其生殖季為4－10月，生殖高峰為4－7月，且為多次產卵。1993年的生殖季則至4月尚未開始。兩性的體型有顯著差異，雄魚的平均體長較雌魚為大，其中生殖腺已達性成熟狀態的雄魚，其平均體長亦較雌魚為大。所發現已達性成熟的最小雌魚及雄魚分別為79mm與75mm，雌魚於長至110mm以上生殖腺完全達到性成熟狀態，而雄魚長至130mm時仍有8%未達性成熟。因此大部份雄魚要比雌魚長至較大全長才達到性成熟狀態。體型較大的雌魚其孕卵數較多，但是卵徑並不會比較大。體型較小的雌魚貢獻在生殖方面能量的比例不會比較少。因此可能由於生殖策略不同而造成兩性體型的差異。

關鍵字

臺灣馬口魚 ； 追星 ； 卵巢重 ； 體重指標

並列摘要

This research was conducted in Ha-Pen Nature Reserve from February, 1992 to April, 1993. The purpose of this study is to investigate the population structure, sexual differences and reproductive biology of Zacco barbata, an endemic freshwater fish of Taiwan, in Ha-Pen Creek.After more than one year survey, the result showed that the sex ratio of Z. barbata was not significantly different from 1:1. The sexual dimorphism can be distinguished in mature individuals by their secondary sexual characters, which include the pearl organs, locating on the head and anal fins, and the breeding color on lateral sides. Generally speaking, males were larger than females in the average total length. The smallest sexually mature females and males investigated, were 79 mm and 75 mm, respectively.From GSI (gonadosomatic index) data, gonad development and egg diameter, we found out that the breeding season of Z. barbata in Ha-Pen Creek was from April to October in 1992, and the peak of breeding season was from April to July. Based on the development of eggs in ovary, we discovered that females of Z. barbata have multiple spawning.Females with longer total length usually had heavier ovaries, due to containing more eggs instead of bigger eggs. We suspected that the relative energy input to the breeding efforts in smaller females were about the same as that of larger ones. The breeding strategy taken by Z. barbata was discussed in the report.

並列關鍵字

Zacco barbata ； Pearl organs ； GSI