The present study deals with the length-weight relationship, relative condition factor, and morphometric and meristic characters of Threadfin sea catfish, Arius arius (Hamilton, 1822) from Hooghly-Matlah estuarine system, West Bengal, India. A total of 391 samples (243 females and 148 males) with the size ranging from 52 to 254 mm total length (TL) and weight ranging from 1.62 to 176.75 g were analyzed for a period of one year (April 2017 to March 2018). The ‘b’ value was estimated as 3.065, 3.127, and 3.104 for male, female, and pooled samples, respectively exhibiting positive allometric growth. The monthly mean relative condition factor (Kn) values ranged from 0.923 to 1.309 for males and 1.003 to 1.085 for females, respectively showing the good condition of the species. Fourteen morphometric characters analyzed revealed that the total length exhibited a highly significant correlation (p < 0.05) with most of the morphometric parameters. The analysis of meristic characters of A. arius found that the first dorsal fin bears 1 spine and 7 soft rays, pelvic fin is with 6 soft rays, pectoral fin bear 1 spine and 8-11 soft rays, anal fin bears 14-17 soft fin rays and the caudal fin is with 16-23 soft rays.

中文翻译：

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西孟加拉邦Hooghly-Matlah河口的Arius arius（Hamilton，1822）的长度-体重关系，相对条件因子和形态研究

本研究研究了fin鱼（Arius arius）的长度-重量关系，相对条件因子以及形态计量学和综合特征。（汉密尔顿，1822年）来自印度西孟加拉邦Hooghly-Matlah河口系统。一年（2017年4月至2018年3月）总共分析了391个样本（243个女性和148个男性），大小在52至254毫米总长（TL）之间，重量在1.62至176.75 g之间。男性，女性和合并样本的“ b”值估计分别为3.065、3.127和3.104，它们均表现出正的异速生长。男性的月平均相对条件因子（Kn）值在0.923至1.309之间，对于女性，则为1.003至1.085之间，分别表明该物种的状况良好。分析的14个形态特征显示，总长度表现出高度显着的相关性（p<0.05），并且具有大多数形态计量学参数。通过对A. arius的功力性状的分析发现，第一背鳍有1条脊柱和7条软射线，盆鳍有6条软射线，胸鳍有1条脊柱和8-11条软射线，肛门鳍有14-17条软肋。鱼鳍和尾鳍上有16-23条柔和的射线。