Mrigal, Cirrhinusmrigala (Ham.1822), one of the Indian major carps widely distributed in Indian inland waters, has considerable aquaculture potential. Knowledge on factors such as age, growth and exploitation pattern is important in fisheries management. Here, we investigated the age structure, growth increment and exploitation pattern of mrigal in Vallabhsagar reservoir, Gujarat (India). Age composition of thestudied fish was 1+ to 9+ age groups with mean total lengths 40.78, 50.99, 59.82,66.32,70.72, 74.56, 77.80, 80.22 and 82.50 cm. The corresponding growth rate in terms of length were 40.78, 10.21, 8.83, 6.50, 4.40, 3.84, 3.24, 2.42 and 2.28 cm observed for these age groups. The growth increment was maximum at the initial age group whereas it was moderate to low in the subsequent years of the age. The exploitation patterns of fish were 3.94 for +1, 32.02 for +2, 22.17 for +3, 25.12 for +4, 2.96 for +5, 6.16 for +6, 4.43 for +7, 2.46 for +8 and 0.74% for +9 age classes. Results depict that exploitation pattern of fish was high at early age fish stock than the higher age classes. The exploitation pattern for 1+ to 3+ age classes was 58.13%, and 41.87% contributed by 4+ to 9+ age classes. Higher catch rate of younger fishes is not a good sign for natural stocking of fish i.e., mrigal in the Vallabhsagar reservoir.

中文翻译：

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印度古吉拉特邦Vallabhsagar水库的西里尔香茅（Ham。1822）的年龄结构，生长速率和开采方式

印度鲮，Cirrhinusmrigala（Ham.1822）是广泛分布于印度内陆水域的印度主要鲤鱼之一，具有相当大的水产养殖潜力。关于年龄，生长和开发方式等因素的知识在渔业管理中很重要。在这里，我们调查了印度古吉拉特邦Vallabhsagar水库的泥质年龄结构，生长增量和开采模式。研究鱼的年龄组成为1+至9+年龄组，平均总长度为40.78、50.99、59.82、66.32、70.72、74.56、77.80、80.22和82.50 cm。在这些年龄组中观察到的相应的身长增长分别为40.78、10.21、8.83、6.50、4.40、3.84、3.24、2.42和2.28 cm。在最初的年龄组中，增长增量最大，而在随后的年龄组中，则为中等至低。鱼的开发方式为+1的3.94，+ 2、22的32.02。+3为17，+ 4为25.12，+ 5为2.96，+ 6为6.16，+ 7为4.43，+ 8为2.46，+ 9年龄段为0.74％。结果表明，早期鱼类种群的鱼类开发模式高于较高年龄类别的鱼类。1+至3+年龄段的开发模式为58.13％，而4+至9+年龄段的开发模式为41.87％。幼鱼较高的捕获率并不是自然放养鱼类的好兆头，例如瓦尔拉萨加尔水库中的海rig。