Length-weight relationships of four difficult-to-sample Caspian endemic gobies (Teleostei: Gobiidae): Benthophilus persicus, Benthophilus baeri, Knipowitschia longecaudata, and Hyrcanogobius bergi

The present study provides the length-weight relationships (LWRs) for four difficult-to-sample Caspian endemic gobies for the first time: Benthophilus persicus, Benthophilus baeri, Knipowitschia longecaudata, and Hyrcanogobius bergi. They were collected from shallow and deep waters of the southwestern Caspian Sea using various methods, including beach seining, scuba diving, and deepwater bottom beam trawls. The slope (b) of LWRs ranged from 2.874 for B. baeri, to 3.408 for H. bergi with coefficient of determination higher than 0.918. The b values showed significant differences between the sexes of all species.