Trophic position of archerfish species (Toxotes chatareus and Toxotes jaculatrix) in the Malaysian estuaries

Summary The study objectives were to identify (i) the diet composition of two co‐occurring archerfish species (Toxotes chatareus and Toxotes jaculatrix), (ii) their potential food preferences, and (iii) their overall trophic level in Malaysian estuaries. For this purpose the stomachs of 128 archerfishes ranging in size of 9.8–22.5 cm and 8.7–23 cm, respectively, were examined from selected Malaysian estuaries. Crustaceans, in particular red clawed crab (Sesarma bidens), occurred in the majority of stomachs and constituted 72.55 and 66.43% of the diet by weight in T. chatareus and T. jaculatrix, respectively. Insects were mostly Formicidae, Dytiscidae, Araneidae, and Cerambycidae and occurred in 10.8, 12.0; 5.1, 6.3; 4, 5.3; 3.2, 1.7% in T. chatareus and T. jaculatrix species and constituted the second most important food category consumed. Other crustaceans and shrimp (Penaeus sp.) constituted 4.4 and 2.7% of the diet by weight and were the third most important food type consumed by the two species. Moreover, these species hardly ever exhibited cannibalistic traits; Toxotes spp. comprised only 5.5% of stomach contents and was observed only in the T. jaculatrix species. Stomach content and trophic level analysis denoted that T. chatareus and T. jaculatrix are strongly carnivorous species. Furthermore, diets did not differ significantly between sizes or sexes and geographic location.