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.