FISHERY BULLETIN: VOL. 72, NO. 4 



than the sparids for this particular task. Of even 

 more primitive stock than the sparid, the 

 muraenid eel Echidna zebra has crushing denti- 

 tion, but its prey seem to be primarily large crabs 

 that it takes regularly from reef crevices in day- 

 light. There is no evidence that it can crush the 

 heavy gastropods so prominent in the diets of the 

 more advanced sparids and diodontids. 



CONCLUSIONS 



1. The feeding relationships of fishes on coral 

 reefs in Kona, Hawaii, follow essentially the same 

 pattern as do feeding relationships of fishes on 

 coral reefs elsewhere. 



2. Nocturnal habits have had a long history in 

 teleostean fishes, and are widespread among the 

 more generalized forms, including many of the 

 clupeids, holocentrids, serranids, kuhliids, 

 priacanthids, apogonids, lutjanids, and others. 

 These large-mouthed predators find night feeding 

 adaptive because that is when their prey — mostly 

 small, motile crustaceans — are in exposed loca- 

 tions and thus vulnerable to their straightfor- 

 ward attack. 



3. Piscivorous predators that have a 

 generalized feeding mechanism, and which attack 

 with a straightforward charge, for example cer- 

 tain large carangids, are mostly crepuscular. 



4. Certain piscivorous predators that have a 

 generalized feeding mechanism feed effectively 

 during the day, as well as during twilight, by 

 ambushing or stalking their prey. The ambushers, 

 which include certain synodontids, serranids, 

 scorpaenids, and bothids, typically have cryptic 

 morphology, coloration, and behavior. The stalk- 

 ers, which include the aulostomids, fistulariids, 

 belonids, and sphyraenids, typically have long, 

 attenuated bodies. 



5. In acquiring features adaptive for hunting 

 in reef crevices, muraenid eels have become 

 highly successful, capitalizing on the otherwise 

 effective shelter-seeking habits of small reef ani- 

 mals. Although many small reef animals become 

 more vulnerable to eels when they shelter in reef 

 crevices, they find these refuges adaptive when 

 resting, injured, or distressed, because they are 

 relatively safe here from the even greater threat 

 from predators that exists on the surface of the 

 reef. 



6. The mullids use their distinctive sensory 

 barbels to locate prey that are sheltered under the 

 superficial covering of the reef and adjacent sand. 



Some mullids are best adapted to capture such 

 prey at night, others to capture such prey in day- 

 light, and some feed effectively during both day 

 and night. At least some use their barbels not only 

 to detect prey, but also to drive them into the open. 



7. Most fishes on Kona reefs, like fishes on 

 coral reefs elsewhere, are among the more re- 

 cently evolved teleosts, having reached, or passed, 

 the percoid level of structural development. 



8. The adaptability of the perciform feeding 

 apparatus has given rise to a wide variety of forms 

 that have diverged from one another primarily on 

 the basis of differing food habits. Much of this 

 diversity has resulted from adaptations that cope 

 with specific defensive characteristics of the or- 

 ganisms on which these fishes feed. 



9. Just as nocturnal and crepuscular habits 

 predominate among the more generalized coral- 

 reef fishes, diurnal habits predominate among the 

 more advanced, specialized forms, including most 

 of the higher Perciformes, and Tetraodontiformes. 

 Some of the most advanced of all, however, includ- 

 ing the diodontids, are nocturnal. 



10. Some higher teleosts, including certain 

 chaetodontids, labrids, and balistids, have 

 specializations that permit them to capture, dur- 

 ing daylight, nocturnal forms hidden under cover. 

 Such prey include forms like motile crustaceans 

 that expose themselves at night, and at that time 

 become the major prey of generalized nocturnal 

 fishes. 



11. Some advanced teleosts, including certain 

 chaetodontids, labrids, and pomacentrids, are 

 specialized to pluck tiny prey, such as amphipods, 

 from among vegetation and other benthic cover. 

 These prey are too small, and too cr5q)tic, to be 

 taken after dark or by predators with a large 

 mouth. This plucking habit preadapted certain 

 species for cleaning ectoparasites and other ma- 

 terial from the bodies of other fishes. 



12. Fishes that prey mostly on sessile inverte- 

 brates, like sponges and coelenterates, are highly 

 evolved diurnal species, including certain 

 chaetodontids, pomacentrids, balistids, and 

 monacanthids. These predators have specialized 

 feeding structures and techniques that handle 

 various noxious or toxic defensive features in their 

 prey, including spines, spicules, nematocysts, 

 tough fibrous tissues, and heavy armour. And they 

 take these sessile animals in daylight because 

 only moving prey are effectively sensed by visu- 

 ally feeding predators after dark. 



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