Investigation Food Diet of Cobitis taenia in Talar River (Mazandaran Province)

Abstract

Perch sweeper fish with scientific name Cobitis taenia is one of the Cobitidae family. Since this kind of fish lives in clean waters and in the high areas of Talar River, it can be an index on water implution. This survey on the diet of this specimen is done on two stations (Kaselian and Tajoon) and shallow and high areas of Talar River in Mazandaran (Southern part of Caspian sea) and the duration of this survey is from October 2008 till September 2009. We should mention that fishing was just done by electro-shocker with voltage 300 V. And this fish after fishing is fixation in 10% formalin solution. So 410 perch sweeper fish were examined and the average of relatively length of gut (RLG) was 17.35 cm. The index of vacated intestine (VI) was calculated 43.35% for all samples. From intense of diet points of view (GSI), the most frequency of full intestines was considered in summer and spring. On the other hand, the smallness of relatively length of gut index (RLG < 1) shows that perch sweeper fish's diet manner is inclined to herbivority. In the examination of containing of digestive track, overally 10 kinds of foodstuff were known. Based on amount of this index, 2.67% Chironomidae is known as main bait in all sampling period.