石門水庫集水區玉峰溪台灣鏟頷魚年齡成長與生殖研究

Age-growth and reproduction of Taiwan shoveljaw carp (Onychostoma barbatulum) in Yu-Fong Stream of Shihmen Reservoir watershed

謝昀諭(Yun-Yu Hsieh)

指導教授 ： 李英周

國立臺灣大學/生命科學院/漁業科學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.01544

摘要

台灣鏟頷魚為台灣唯一泛島性分布的淡水魚類，在石門水庫集水區上游亦為優勢族群，然而搜尋過去台灣鏟頷魚相關研究發現缺乏較完整年齡與成長研究，因此本研究進行台灣鏟頷魚之年齡與成長研究，期望透過本研究補充相關資訊並提供未來保育及管理措施的參考資訊。
本研究自2012年2月至2014年4月於新竹縣尖石鄉玉峰溪進行採樣，每月採樣一次，所有樣本於現場會進行尾叉長、體全長、體重測量，並隨機選取數隻樣本浸泡10%福馬林攜回實驗室進行下一步分析，其餘魚隻皆放回溪流。本研究利用年齡形質法估計年齡，樣本魚攜回實驗室後採取鱗片進行年齡與成長研究，接著解剖魚體取出生殖腺判斷雌雄，接著測量生殖腺重計算生殖腺指數(GSI)估計生殖季節。
研究結果顯示，捕獲樣本魚尾叉長介於3.2-22.4cm(n=703)，主要集中在6-10cm，利用攜回研究室的樣本(n=220)進行年齡查定工作發現台灣鏟頷魚的鱗片一年形成一輪，利用Ford-Walford定差法套合von Bertalanffy成長曲線估得成長方程式為：l_t=30.17(1-e^(-0.22(t+1.19) ))。年齡組成以1歲魚最多(41.8%)，其次依序為2歲魚(24.1%)，3歲魚(21.8%)，0歲魚(10.5%)以及4歲魚(1.8%)。總雌雄性比符合1：1，但超過3歲魚的雌雄性比不符合1：1，且以雌魚居多；利用全年GSI變化推估玉峰溪台灣鏟頷魚族群之生殖季節為3-5月。
鱗片可作為研究台灣鏟頷魚年齡的有效形質，未來可增加耳石或脊椎骨等形質與鱗片進行形質間的比對，提升判別正確率。

關鍵字

台灣鏟頷魚 ； 年齡形質 ； 年齡與成長 ； 石門水庫集水區 ； 生殖季節

並列摘要

Taiwan shoveljaw carp (Onychostoma barbatulum) is one of the most distributed primary division freshwater fish in Taiwan. It is also the dominant species in upstream of Shihmen Reservoir watershed. However there is no complete are-growth research in the past. So this research investigated the age-growth of O. barbatulum to add its basic biological information and wish it can assist future conservation and management decisions.
The present research collected O. barbatulum in Yu-Fong Stream of Shihmen Reservoir watershed from February 2012 to April 2014. All fishes measured the fork length (FL), total length (TL) and body weight (W) onsite and took some fishes randomly immersed with 10% formalin solution back to the lab(n = 220). The present research investigated the age and growth of O. barbatulum based on scales. We also dissected fishes and took out gonads to analysis the sex and gonadosomatic index (GSI) to estimate its breeding season.
The results showed that, the fork length ranged from 3.2-22.4cm (n = 703), and focus on 6-10cm. The rings of scales formed annually. The von Bertalanffy growth curves computed by observed length at- age data and was expressed as l_t=30.17(1-e^(-0.22(t+1.19) )). The age composition of O. barbatulum in Yu-Fong Stream were 0 year old fish 10.5%, 1 year old fish 41.8%, 2 years old fish 24.1%, 3 years old fish 21.8% and 4 years old fish 1.8% respectively. The sex ratio was 1:1 of total sample fishes but not followed of over 3 years old fishes (most were female). We estimated the breeding season of O. barbatulum in Yu-Fong Stream was March to May.
Scale is an ideal age character for age determination for O. barbatulum, and maybe we can use another age characters such as otolith or spine compared with scale to enhance the accuracy of age determination in the future.

並列關鍵字

Taiwan shoveljaw carp (Onychostoma barbatulum) ； age character ； age -growth ； Shihmen Reservoir watershed ； breeding season.

參考文獻

楊芷毓，2011。石門水庫集水區湳仔溝溪之臺灣馬口魚族群生態學研究。國立台灣大學漁業科學研究所碩士論文。

胡通哲、莊明德，2004。台灣鏟頷魚與台灣石魚賓在改良型舟通式魚道溯游試驗之研究。農業工程學報，50(3)：82-88。

胡哲瑋，2011。石門水庫集水區大漢溪上游支流與下游主流河段臺灣石魚賓 之生殖生物學與環境因子比較研究。國立台灣大學漁業科學研究所碩士論文。

Barnes, M. A. and Power, G. 1984. A comparison of otolith and scale ages for western Labrador lake whitefish (Coregonus clupeaformis). Envir. Bio. of Fishes. 10:297-299.

Beamish, R. J. and McFarlane, G. A. 1983. The forgotten requirement for age validation in fisheries biology. Trans, Amer. Fish. Soc. 112:735-743.