HOBSON: FEEDING RELATIONSHIPS OF FISHES 



fragments, P. spilosoma does not neatly snip off 

 the polyps so much as coarsely gouge them from 

 their thecae. 



CONCLUSION. — Peruagor spilosoma is a 

 diurnal omnivore that feeds mainly on scleractin- 

 ian corals, to a lesser extent on algae and other 

 benthic invertebrates. 



General Remarks on Filefishes 



In summarizing their treatment of monacan- 

 thids in the Marshall Islands, Hiatt and Strasburg 

 (1960:105) stated: "There is no question that 

 filefishes derive the bulk of their nutriment from 

 living corals." All of the Oxymonocanthus lon- 

 girostris (a widespread Indo-Pacific species that 

 does not occur in Hawaii) examined by them con- 

 tained only coral polyps, with no skeletal mate- 

 rial. Their account indicates that this species, 

 which has a very long, narrow snout, with teeth 

 protruding from its mouth as long, cupshaped in- 

 cisors, may be among the most highly specialized 

 of coral-feeding filefishes. On the other hand, 

 Randall (1967) found corals to be insignificant as 

 food for West Indian filefishes; of the six species he 

 examined, corals were in the diet of only one, and 

 only as a minor component. According to Randall, 

 the West Indian filefishes take a diverse array of 

 benthic organisms: Algae and sea grasses are 

 major items, along with a variety of benthic in- 

 vertebrates. Thus, Cantherines sandwichiensis in 

 Kona has a diet much like the West Indian species 

 described by Randall, whereas C. dumerili takes 

 largely corals in Kona, just as Hiatt and Strasburg 

 reported it and other filefishes doing in the Mar- 

 shall Islands. Clearly, many filefishes, especially 

 certain Indo-Pacific species, feed heavily on corals, 

 whereas various other filefishes find their food 

 from among other elements of the benthos. 



Filefishes are recognized as being diurnal. For 

 example, Starck and Davis (1966) described C. 

 pullus as resting at night wedged in rocky holes on 

 reefs in Florida. 



Family Ostraciontidae: boxfishes 



Ostracion meleagris (Shaw) — pahii 



This boxfish is widespread on nearshore reefs in 

 Kona, but is nowhere numerous, except occasion- 

 ally in some parts of the boulder habitat. During 

 the day it swims, slowly, close among rocks and 

 coral, now and then picking at the substratum. I 

 saw several in the same places at night, but at the 

 time felt they had been disturbed from resting 

 places by my activity. It was difficult to appraise 

 the nocturnal behavior of this species, owing to its 

 relatively low numbers on the reef and the re- 

 duced visibility after dark, and because the few 

 observations were somewhat ambiguous. 



Of the six individuals (65: 43-80 mm) collected, 

 one speared within 15 min after sunrise as it swam 

 close to the reef had an empty gut, whereas all five 

 taken under similar circumstances, except later in 

 the day (between late morning and late afternoon) 

 had food throughout the gut. The items in the 

 foregut are listed in Table 69. 



CONCLUSION. — Ostracion meleagris feeds on 

 benthic invertebrates during the day. Its noctur- 

 nal status remains uncertain, although tenuous 

 data indicate relative inactivity after dark. 



General Remarks on Boxfishes 



Boxfishes in the tropical Atlantic generally are 

 described as active during both day and night 

 (Starck and Davis, 1966; Earle, 1972; Collette and 

 Talbot, 1972). Tunicates, the major prey of 

 Ostracion meleagris in Kona, were ranked either 



Table 69. — Food of Ostracion meleagris. 



1011 



