摘要
1985年6—10月于长江口共获得白鲟当年的1龄幼鱼标本49尾(体长80—530毫米),进行了有关形态、生长以及食性的观察研究。①幼鱼形态与成鱼基本相似,其体长与体长/眼径以及体长/吻须长呈明显的正相关;②6月21日至10月12日间的幼鱼长度生长方程为L_t=79.9723e^(0.0213t)(式中L_t为体长,毫米;t为天数),其相对增长率以8月为最快;③长江口白鲟幼鱼摄食频度为100%,平均胃饱满指数为198.46,它们是肉食性鱼类,以底栖小型虾类和鱼类为主食,食物共有8类16个可鉴别种类;④考虑到这种珍稀鱼类的种群与资源衰退现状,建议在长江河口区制定必要的保护措施。
Forty nine young Psephurus gladius with body length ranging 80—530mm.collected from the estuary of the Changjiang (Yangtze) River during June to October in 1985 were investigated. The main results in relation to the morphology, growth and feeding habits are as follows. (1) All specimens of the young are similar with the adult in morphology, but the correlations between body length and BL./eye-diameter, and BL./rostral barbel length are significiant positively; (2) The equation of growth in length from 21 June to 12 October is given as L,=79.9723e^(0.0213t), where Lt stands for BL. (in mm.) and t for number of days. The rate of relative growth was found to be highest during August. The relationship between body-length (in mm.) and body-weight (in g.) may be expressed by W=1.5654^(-6) BL.^(3.1432); (3) Food of different quantity were observed in stomach of all specimens and the average fullness index of stomach reaches 198.46. It is a predatory fish feeding mainly on benthic small shrimps, fishes etc., involving 16 identified species belonging to eight groubs. (4) Concerning the depressed population of this precious and rare fish, the authors propose that suitable protective measures in the estuarine region of the Changjiang River should be taken.
出处
《水生生物学报》
CAS
1987年第4期289-298,共10页
Acta Hydrobiologica Sinica
