Length-weight relationship and condition factor for twelve fish species from the Igarapé Fortaleza basin, a small tributary of the Amazonas River estuary

ABSTRACT Length and weight data are useful in fisheries management and standard results of fish monitoring programs. Length-weight relationship (LWR) is used for estimating the weight corresponding to a given length, and the condition factor is used to compare the body condition, fatness or health of fish populations. This study aimed to estimate the LWR and the condition factor for 12 freshwater fish species from the Igarapé Fortaleza basin, a tributary of the Amazonas River system in the State of Amapá, eastern Amazon (Brazil). The coefficient of determination, the allometric condition factor and the allometric coefficient varied among species, and were compared with populations elsewhere. In 83.3% of the species, the allometric coefficient remained within the expected range. This was the first record of LWR parameters for Acestrorhynchus falcirostris.

摘要：体长与体重数据在渔业管理领域应用广泛，同时也是鱼类监测项目的标准产出指标。体长体重关系（Length-weight relationship, LWR）可用于根据给定体长估算对应体重，而肥满度因子则用于比较不同鱼类种群的身体状态、肥满程度或健康水平。本研究针对巴西亚马孙东部阿马帕州境内亚马孙河水系支流伊加拉佩福塔莱萨流域的12种淡水鱼类，估算其体长体重关系与肥满度因子。研究发现，不同鱼类的决定系数、异速生长肥满度因子及异速生长系数均存在差异，并将上述参数与其他区域的鱼类种群进行了对比分析。其中83.3%的物种，其异速生长系数处于预期区间内。尖吻狗脂鲤（Acestrorhynchus falcirostris）的体长体重关系参数为全球首次记录。