Ostract:ontx.da&. Trunk;Elsb-es 



TrunRfxshes comprise a small but often conspicuous element of the 

 flsh- fauna of a reef. Their occurrence in exposed places on the 

 reef and plain, day and night, suggests some measure of Immunity 

 from predatlon that may be afforded by the bony box that encases 

 the fishes' body. Food habits are varied, but many eat some plant 

 material. Five species are known from the West Indies; three were 

 encountered during the study. 



Acanthostraclon quadricornls (Linnaeus) . Scrawled Cowfish 



Solitary individuals apparently of this species were commonly seen 

 on the algal or sand plain within 35 meters of the reef. At night, 

 they were inactive but exposed on the same plain where they occurred 

 during the day. 



None responded to feeding trials, but one was seen biting a tip from 

 a Halimeda plant on the plain. Randall (1967) examined six specimens 

 and found Halimeda and blue-green alga to comprise 7.2% of the 

 stomach contents, and the sea grass, Thalassia , 3.0%. 



Lactophrys trigonus (Linnaeus) . Trunkflsh 



Several large trunkfishes of this species were observed along the 

 face of the reef and on the plain to at least 25 m distant, day and 

 night. They were not seen eating, but Randall (1967) reported that 21 

 specimens contained 4.9% algae (4 filamentous, 2 calcareous, 2 fleshy, 

 and 1 leafy species) as well as 3.0% of the sea grasses, Syringodium 

 and Thalassia . Randall (1968) suggested that the species is primarily 

 a resident of the sea grass habitat. 



Lactophrys triquerter (Linnaeus ) 



Lone smooth trunkfishes were occasionally encountered on the reef and 

 at night, on the plain within 30 m of the reef. They were not observed 

 eating, but food habits apparently may range from primarily herbivorous 

 (Beebee and Tee-Van, 1928; Longley and Hlldebrand, 1941) to primarily 

 carnivorous (Randall, 1967). Randall examined 17 specimens from the 

 West Indies and found only 0.9% of the alga, Halimeda , and 1.2% of 

 the sea grasses, Halophila and Thalassia . 



VI-158 



