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Fishery Bulletin 92(3), 1994 



crabs were more important by all measures. Two M. 

 amaena specimens contained a total of three lobsters. 

 Fish were moderately important prey by frequency 

 and volume. Many prey specimens appeared to be 

 eels, probably mostly ophichthids. Polychaetes were 

 the most important benthic prey, present in about 

 70% of all fish and providing over 10% of all prey by 

 numbers and volume. 



Twenty-two specimens from Puako contained prey 

 identifiable to some level (Table 2). Nearly 70% of 

 these contained crab megalops larvae; a hermit crab 

 was identified in one of these and a galatheid crab, 

 Galathea spinosorostris, in another. Crab larvae were 

 also the major prey in numbers (over 70% ) and vol- 

 ume (35%) and were strongly dominant in the IRI 

 (Table 3.). Shrimp were eaten by the second largest 

 number offish (nearly 30%) and were second in im- 

 portance numerically (over 10%), but minor in vol- 

 ume. They were far less an important prey at Puako 

 than at JA, and were more evenly divided among 

 Alpheidae, Palaemonidae, and Hippolytidae (includ- 

 ing two Saron marmoratus ). Lobsters ( three individu- 

 als) appeared in only three guts ( 14%), but they ac- 

 counted for over 20% of total prey volume. Both the 

 slipper lobster, Scyllarides squammosus, and the 

 Hawaiian clawed lobster, Enoplometopus occi- 

 dentalis, were eaten. No other groups made major- 

 individual contributions to the diet. However, sto- 



matopods and fish accounted for at least several per- 

 cent of the number of consumers (frequency %) and 

 volume. One octopus appeared in the diet at Puako. 

 Benthic prey included at least a few percent gastro- 

 pods (by the various measures) and a polychaete 

 specimen. Nearly 80% of all fish also contained some 

 quantity of unidentifiable crustacean parts, which 

 accounted for over 25% of the total prey volume. 

 Calculated as a percent of only the total prey identi- 

 fiable to more specific groups, the volume % of each 

 of those groups was considerably higher. 



Only nine specimens from the NWHI contained 

 prey identifiable to any level (Table 2). The total 

 amount of prey recovered was small. Fish (including 

 at least one pomacentrid), shrimp, juvenile crabs (in- 

 cluding majids), and stomatopods were found in one 

 or two guts each in total numbers of one to three 

 individuals each. Six guts contained unidentifiable 

 crustacean parts, which accounted for over 40% of 

 the total diet volume. Fish were next in volume, and 

 the other three groups contributed little volume. 



At all three locations, the diet of M. amaena was 

 heavily dominated by small juvenile stages of crus- 

 tacean species that become much larger as adults. 

 These prey included all the major groups of large 

 crustaceans that are dominant in the diets of many 

 demersal species of reef fishes studied in Hawaii 

 (Parrish et al., 1985). Besides the crab and shrimp 

 prey — quantitatively important in the diet of M. 

 amaena at all three locations — stomatopods were 

 eaten at all locations, and were the dominant prey of 

 the Myripristinae generally in the NWHI (Parrish, 

 unpubl. data). Pseudosquilla oculata was a stomato- 

 pod species identified in our M. amaena specimens 

 that also was prominent in the diets of other Myri- 

 pristinae and other demersal reef fishes in our stud- 

 ies in Hawaii. 



Small peracaridan crustaceans were conspicuous 

 in the diet at JA (Table 2). Mysids and tanaids were 

 present in the gut contents of many fish specimens, 

 and each group contributed a few percent of the to- 

 tal number and volume of prey. Only one individual 

 of each was identified at Puako. Amphipods were 

 somewhat less widely found as diet components at 

 JA and their abundance was trivial. At Puako they 

 were present in about 18% of the fish and made up 

 about W'< of numbers but were trivial in volume. Most 

 of those identified were gammarids. A few isopods 

 were found in JA specimens, and traces of copepods 

 were found in Puako specimens. More peracaridans 

 and other small crustaceans were very likely part of 

 the residue of unidentifiable crustacean parts that 

 appeared widely at all locations. 



Myripristis amaena showed the expected strongly 

 nocturnal feeding habit. At JA, guts from all 64 speci- 



