Evaluating the effectiveness of the coal ash artificial reefs at Wan-li, northern Taiwan

Abstract

本篇記述東港附近大眼鯛(Priacanthus macracanthus)之漁業生物學特性和其與龜山島產大眼鯛比較之結果。計數形質均甚穩定且各計量形質與體長均有顯著的直線廻歸關係存在。生殖期為五月至九月，成熟雌魚之抱卵數為110,000至320,000（粒／尾）。最小性成熟體長為170 mm。年齡查定以鱗片為形質，輪紋一年形成兩輪，一次在十二月至一月間；另一次在六至七月間。雌、雄之成長不同，以von Bertalanffy方程式表示分別為：雌 L(下标 t)=441.07(1-e(上标 -0.136(t+2.90)))，雄 L(下标 t)=401.68(1-e(上标 -0.128(t+2.632)))．經變積分析比較結果顯示，計數形質在兩海域間無明顯差異，但兩海域間計量形質和體長之關係有明顯差異，兩海域大眼鯛的成長有明顯差異，東港產者成長較快，可能為兩不同系羣。This paper presents some aspects of the fishery biology of big eye,Pri-acanthus macracanthus,caught in Tungkang waters southwestern Taiwanduring the period from November 1981 to November 1982.The results obtainedare compared with that of Guei-Shan Island waters.The meristic charactersare steady.The morphometric character shows a significant linear relationwith fork length.Spawning season of the big eye is from May to September.Fecundity is from 110,000 eggs/fish to 320,000 eggs/fish.The size at firstmaturity is approximately 170 mm in fork length.The age of the fish wasestimated by scale reading.Two resting zones were formed every year,oneis from December to January and the other from June to July.There is asignificant difference of growth between sexes.The von Bertalanffy growthequations are estimated as:L(subscript t)=444.07(1－e(superscript -0.136(t+2.90)))for females,and L(subscript t)=401.68(1-e(superscript -0.128(t+2.632)))for males,respectively.There are no significant differencesin meristic characters for big eye between Tungkang and Guei-Shan waters,while the regression of morphometric characters on fork length are differentbetween these two waters.The adjusted mean of the regression line in Tung-kang waters is larger than that in Guei-Shan Island waters.This indicatedthat the growth of this species in the two waters are significantly different,the fish in Tungkang waters grow faster than those in Guei-Shan Islandwaters.It is suggested that the big eye in the northeastern and the southwesternwaters of Taiwan might be originated from two different stocks.