length-weight relationship and condition factor of seven fish species from shahrbijar river, southern caspian sea basin, iran

length-weight relationship and condition factor were estimated in seven fish species, including barbus cyri, capoeta gracilis, alburnoides eichwaldii, pseudorasbora parva, ponticola cyrius, cobitis keyvani and acanthalburnus microlepis from shahrbijar river, guilan province, iran. a total of 416 specimens ranging from 18 to 135 mm in total length and from 0.06 to 19.25 g in total weight were collected. based on the results, growth coefficient values “b” ranged from 2.615 (in b. cyri) through 3.001 (in a. microlepis). all length-weight relationships were significant (p<0.05), with r2 higher than 0.819. the five species viz. c. gracilis, p. parva, c.keyvani, p. cyrius, and b. cyri showed allometric (b<3<b) while two species viz. a. microlepis and a. eichwaldii showed isometric (b=3) growth patterns. condition factor ranged from 0.57 (in c.keyvani) through 1.11 (in p.cyrius). all linear regressions were highly significant (p<0.05). the present study provides the first baseline information on the length - weight relationships of the seven fish species from shahrbijar river which may be useful for further fisheries management of these species.