红水河四大家鱼资源现状调查分析

Investigation and analysis on resources of four major Chinese carps in the Hongshui River

【目的】调查评估红水河四大家鱼资源现状,为其渔业资源可持续开发利用提供参考依据。【方法】在红水河干流设置天峨、东兰、大化、都安及来宾5个监测站位,按季度现场采样和固定渔船捕捞记录,调查红水河四大家鱼占渔获物比例、种群结构特征及其繁殖生物学特性。【结果】红水河四大家鱼占渔获物比例合计为10.38%,其排序为鳙（3.41%）〉青鱼（2.94%）〉鲢（2.93%）〉草鱼（1.09%）。青鱼体长以400.1-600.0 mm为主（占61.53%）,体重以≥1200.1 g为主（占84.62%）;年龄由0＋-5＋共6个年龄组组成,各年龄组百分比相对较接近;草鱼体长以200.1-400.0 mm为主（占72.41%）,体重以200.1-700.0 g居多（占55.17%）,年龄以0＋龄和1＋龄居多,分别占草鱼总数的48.3%和34.5%;鲢体长以200.1-600.0 mm为主（占96.55%）,体重以≥1200.0 g居多（占48.28%）,年龄以1＋龄最多,占鲢总数的55.2%;鳙体长以200.1-400.0 mm为主（占52.94%）,体重以200.1-700.0 g为主（占55.56%）,年龄以0＋龄最多,占鳙总数的59.3%。四大家鱼的亲鱼比例为38.9∶27.8∶27.8∶5.5,其性比（雌∶雄）分别为：青鱼42.9∶57.1、草鱼55.0∶45.0、鲢62.5∶37.5、鳙50.0∶50.0,均接近于l∶l;相对繁殖力均值为青鱼11.85-17.63粒/g、草鱼32.33-43.48粒/g、鲢10.48-16.70粒/g、鳙5.93粒/g。【结论】红水河四大家鱼资源量呈下降趋势,草鱼、鲢、鳙捕捞压力过大,其种群呈小型化和低龄化;四大家鱼的个体繁殖力偏低,其群体自我补充能力基本丧失。

【Objective】In order to provide theory basis for sustainable development of fishery resources, the current situation of four major Chinese carp resources in Hongshui river was investigated. 【Method】Five survey stations, including Tiane, Donglan, Dahua, Duan and Laibin, were selected in the main stream of Hongshui river. The catch proportion,population structure feature and reproductive biology of four major Chinese carps were investigated through quarterly onsite sampling and fixed fishing log records. 【Result】The catch proportions of four major Chinese carps amounted to 10.38%,which were ranked as follows ： Aristichthys nobilis（ 3. 41 %）〉 Mylopharyngodon piceus（ 2. 94 %） Hypophthalmichthys molitrix（2.93%） Ctenopharyngodon idellus（1.09%）. And The M. piceus with body length of 400.1-600.0 mm accounted for 61.53%, and M. piceus with body weight of equal to or more than 1200.1 g accounted for 84.62%. The age structure of M. piceus was composed of 6 age groups, and ranged from 0＋to 5＋, and the percentage of each age group was almost similar with that of other age group. The C. idellus with body length of 200.1-400.0 mm accounted for 72.41%, and C. idellus with body weight of 200.1-700.0 g accounted for 55.17%, and the 0＋and 1＋age groups were the most, which accounted for 48.3% and 34.5% of total number, respectively. H. molitrix with the body length of 200.1-600.0 mm accounted for96.55%, and H. molitrix with body weight of equal to or more than 1200.0 g accounted for 48.28%, and the 1＋age group was the most, which accounted for 55.2%. The A. nobilis with body length of 200.1-400.0 mm accounted for 52.94%, and A. nobilis with body weight of 200.1-700.0 g accounted for 55.56%, and the 0＋age group was the most, which accounted for 59.3%. Furthermore, the parent fish ratio of four major Chinese carps was 38.9∶27.8∶27.8∶5.5, and their sex ratios（female： male） were 42.9∶57.1, 55.0∶45.0, 62.5∶37.5 and 50.0∶50.0, respectively, and all ratios were close to l∶l. Moreover,their mean relative fecundity were 11.85-17.63, 32.33-43.48, 10.48-16.70 and 5.93 grains/g, respectively. 【Conclusion】The resources of four major Chinese carps in Hongshui River presented decreasing trend. And C. idellus, H. molitrix and A. nobilis show obvious miniaturization and younger-age trends because of overfishing. Furthermore, four major Chinese carps basically lose self-reinforcing ability of population on account of low fecundity.