FISHERY BULLETIN; VOL. 72, NO. 4 



elsewhere; that is, it forms relatively inactive 

 schools during the day, then disperses at nightfall 

 and hunts prey after dark. This pattern is known 

 for L. argentiuentris in the Gulf of California 

 (Hobson, 1965, 1968a), and for L. griseus and 

 others in the tropical Atlantic (Starck and Davis, 

 1966). Randall and Brock (1960) reported pre- 

 dominantly nocturnal feeding by L. vaigiensis in 

 Tahiti and often found this snapper in large ag- 

 gregations during the day. 



Family Sparidae: porgies 



Monotaxis grandoculis (Forskal) — inu 



In Kona, this porgy is most numerous near 

 basalt reefs that are exposed to the prevailing sea. 

 During the day it typically hovers 2 to 3 m above 

 the reef, either in loose aggregations of 4 to 10 fish, 

 or as solitary individuals. When congregated, 

 most individuals display broad bars on their sides 

 dorsally; although this same color pattern occurs 

 frequently in solitary fish, these often are overall 

 pale grey. Those I observed in Kona during the day 



always seemed inactive; however, Hiatt and 

 Strasburg ( 1960) reported individuals in the Mar- 

 shall Islands excavating prey buried in the sand, 

 presumably during daylight. In Kona, M. grand- 

 oculis disperses from its daytime assemblages at 

 nightfall and forages as solitary individuals 

 throughout the night. After dark, many move into 

 shallower water than is frequented by the species 

 in daylight. The nocturnally active individuals 

 sometimes show the barred color pattern but are 

 most often plain grey (Figure 22). 



Of five specimens (312: 244-397 mm) speared 

 during day and night, one that was taken from an 

 aggregation late in the afternoon was empty, 

 whereas all four that were speared at night (later 

 than 4 h after sunset and before first morning 

 light) were full of food, as listed in Table 22. 



Although the gut contents were relatively fresh, 

 the shelled items had been reduced to crushed 

 fragments — presumably by the large molarform 

 jaw teeth of this fish. 



Prey taken by this porgy in Kona are much the 

 same as taken by the same species in the Marshall 

 Islands (Hiatt and Strasburg, 1960) and Gilbert 

 Islands (Randall, 1955). 



Figure 22. — Monotaxis grandoculis, a porgy, showing its plain grey coloration as it swims close to the reef at night. 



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