FOOD HABIT AND REPRODUCTIVE BIOLOGY OF THREATENED FISH SPECIES, Cirrhinus reba (Hamilton, 1822)

Abstract

Cirrhinus reba known as Khorkia bata or Bhagna belongs to the family cyprinidae. A study was conducted on the food habit of C. reba collected from Atrai river of Dinajpur district for a period of 6 months from September, 2015 to February, 2016. Different items of food were determined by the frequency of occurrence method. It was found that debris (22.41%) was the most dominant food item in the gut of C. reba followed by mud (18.56%) and sand (14.97%). The other food items were phytoplankton (30.85%) and zooplankton (4.31%). It was omnivorus fish with relative length of gut was (5.36 ± 1.22). Another experiment was conducted on the fecundity and GSI from March to August, 2015. Gonadosomatic index was calculated and the fecundity was determined by gravimetric method. The highest gonadosomatic index (37.38 ± 2.31) was found in the month of July. The lowest fecundity 406.67 was recorded in the fish having 16.3 cm length and 39.83 g body weight. The highest fecundity (167325) was recorded in the fish having 19.6 cm length and 93.3 g body weight. The fecundity was found to increase with the increase total length following the equation, F = 0.046 TL + 2.339 (r = 0.645) and the fecundity was also found to increase with the increase of body weight following the equation, F = 0.262 BW + 1.231 (r = 0.934). It was also found that the fecundity was increasing with equation, F = 0.700 OW - 4.817 (r = 0.853). The relationship between fecundity and total length, body weight, and ovary weight were found to be linear and significant. The investigation revealed some aspects of feeding and reproductive biology of the threatened fish C. reba. Further details investigation including histology is high required for the feeding and reproductive biology of C. reba.