Rajaguru: Biology of Cynoglossus arel and C lida from Indian waters 



337 



Food vs. fish size In C. arel, the dominant size-group 

 in both sexes is 185-229 mm TL (54% of males, and 

 40% of females). Females in this size-group had eaten 

 23 types of prey, while males consumed only 16 types 

 (Table 7). In the remaining size-groups of both sexes, 

 there is no obvious difference in the number of prey 

 types consumed (Tables 6, 8-9). In both sexes of C. arel, 

 fish <275mmTL preyed predominantly on polychaetes 

 (55.1-66.3% IRI in males, 53.4-62.7% IRI in females), 

 whereas in fish >275mmTL the polychaetes were of 

 lesser importance (10.5% IRI in females, <5.0% IRI 

 in males), with fish remains being the most abundant 

 (54.5% IRI in males, and 48.9% IRI in females) (Tables 

 6-9, and Fig. 3). 



In both sexes of C. lida, fewer prey types were 

 consumed by fish >200mmTL (8-9 prey types) and 

 by fish <136mmTL (10-13 types), compared with 

 fish 137-199mmTL (16-19 types). Among fish 

 <200mmTL, polychaetes were the most abundant 

 prey in both sexes (67.2-89.0% IRI in females, 

 61.0-81.5% IRI in males) (Tables 10-13, Fig. 4). 

 Among the fish >200mmTL, polychaetes were the 

 most abundant prey only in females (90.2% IRI), 

 whereas polychaetes were the second-most important 

 prey in males (28.2% IRI) and prawns the most abun- 



dant prey (52.6% IRI) (Table 14, Fig. 4). 



Seasonal variations in diet composition In male C. 

 arel, polychaetes were dominant, except in February, 

 May, and December (Table 1). During these 3 months, 

 other prey items, viz, prawns (in May), crustacean 

 fragments (in December), and fish remains (in 

 February) were more important in the diet. In females, 

 polychaetes also formed the primary food during 6 

 months (April, July, August, September, October, and 

 December). In other months, prawns (January, March, 

 May, and June), crustacean fragments (February), and 

 fish remains (November) were the primary food con- 

 sumed (Table 2). 



In male C. arel, prawns were the secondary prey item 

 for 6 months (February, June, July, August, Septem- 

 ber, and October), with polychaetes in May and De- 

 cember, crustacean fragments in March and April, and 

 fish remains in January and November. In females, 

 crustacean fragments were the secondary prey item 

 for 5 months (January, March, April, May, and 

 December), prawns for 3 months (July, September, and 

 October), polychaetes for 2 months (June and 

 November), and fish remains for 2 months (February 

 and August). The tertiary food group in the diet of 



