non-commercial fish species in by-catch composition of shrimp trawl landing from mahshahr creeks

non-commercial fish species of shrimp trawls were studied monthly from october 2005 to september 2006 in mahshahr creeks (darvish, doragh, bihad, ghazaleh, ghanam, zangi and patil). the trawl nets had a cod-end mesh size of 24mm. total catch was 6431 individuals weighing 55.5kg, and included 14 species of non-commercial fish species belonging to 14 families. the caught shrimp species were from penaeidae; comprising only 30% of the total catches (4506 individuals weighting 44kg). dominant species were lieognathus hindus (54.8%), metapenaeus affinis (18.2%) and parapenaeopsis stylifera (9.8%). maximum fish abundance was observed in march 2005 (98/3%) and for shrimp in june (66.2%). bihad creek had the maximum  percentage of fish (91.8%) by-catch and shrimp (42.9%) abundance. we conclude that the by-catch percentage of non-commercial fish is higher than shrimps in the study areas. warm months witnessed the highest abundance of shrimp while january-march was the time period when by-catch was most abundant.