印度北方河流中主要鲤科鱼类卡拉(鱾)的年龄和生长

为了获得印度北部赣达(Ganga)盆地河流中野生卡特拉(鱾)种群的年龄结构和重要生长参数,对该鱼的年龄和生长进行了研究.鳞片取自商业捕捞和实验室饲养的样品.根据研究分析,该鱼最大年龄可达8龄;巴吉拉蒂河(Bhagirathi R.)的种群平均体长为521.51 mm,退算体长为288.9-1132.3 mm;旁遮普邦(Punjab)Satluj河种群平均体长为641.6 mm,退算体长为335.4-1096.08 mm.2龄时,种群线性生长率(Cl)和体重增加率(Cw)表现出迅速下降的趋势.其它生长参数值(Clt)也呈现快速下降.退算体长差异(ANOVA)分析显示,生活在赣达盆地不同流域中的种群,1 -4 龄组的长度差异较明显(P<0.05),高龄组(5 -8 )差异不显著.根据本项研究结果,提出了对印度北部赣达盆地相关河流中生活的野生卡特拉(鱾)种群资源持续利用的对策.

Age and growth profile of Indian major carps Catla catla from rivers of Northern India

In the present communication age and growth of Catla catla (Hamilton-Buchanan 1822) was studied in order to obtain the information on its age structure and important growth parameters in the wild populations of rivers of the Ganga basin in the Northern India. Scales were collected from commercial and experimental catch. Based on the analysis we found C.catla with a maximum age group 8+ from river Bhagirathi where mean total length (TL) was 521.51 mm and the back calculated length were ranged from 288.9 to 1132.3 mm and from river Satluj, Punjab with a mean total length of 641.6 mm and back calculated length data were ranged from 335.4 to 1096.08 mm. The specific rate of linear growth (Cl) and specific rate of weight increase (Cw) of the entire population exhibited sharp decreasing trend in 2+ age group. The value of other growth parameter (Clt) showed an abrupt decreasing trend. Analyses of variances (ANOVA) of the back-calculated length data showed significant variation (P<0.05) in length attainment between the different drainages of river Ganga basin for the age groups up to 1+ to 4+ only, however, no significant variations was observed for the higher age groups (5+ to 8+). Based on this study strategies can be made for sustainable exploitation of the Catla catla from wild population with reference to rivers of Ganga basin in the Northern India.