112 



PAPERS FROM TORTUGAS LABORATORY vol. xxxiv 



Rhegma brederi Hildebrand 1 



Rhegma brederi Hildebrand, in Longley and Hildebrand, Carnegie Inst. Wash. Pub. 

 517, 1940, p. 244, fig. 11 — Tortugas, Florida. 



Family PRIACANTHIDAE. Bigeyes 



Priacanthus cruentatus (Lacepede). Glass-eyed snapper 



Specimens were occasionally seen in crevices of the beach rock, usually deep 

 down in the fissures, sometimes using their fins to brace themselves and hold 

 their place in narrow crevices. I observed this species only once fully exposed in 

 broad daylight. On this occasion it appeared to have been driven from hiding in 

 Acropora by the alternate thrust and tug of a ground swell. Yet, retiring as it is, 

 it is not easily frightened, as one once permitted me to work beside it with 

 hammer and chisel to cut a window through the coral that hid it from the 

 camera. It comes out of retirement soon after sunset, and at dawn it may be seen 

 once more, appearing by fours and fives, but shortly afterward it disappears 

 again in the fastnesses of the reef. More than two score young, 45 to 75 mm. in 

 length, were included in a few pailfuls of waste from the Bird Key tern rookery. 



D. X,i2'/2 to i4 1 / 4 ; A. III,i3 1 /2 to 1414 ; gill rakers about 16. 



Feeding occurs chiefly at night. The food includes annelids, crustaceans of 

 many kinds, and small fishes. 



It is red or red-brown, with eleven silvery bands, unevenly spaced; lower half 

 of body dotted with spots of silver a little less than pupil in diameter; soft dorsal, 

 anal, and caudal with rows of dark spots between the rays. 



Only once a normal change in coloration was noticed, as the fish in the morn- 

 ing before sunrise were far from their reddest, though their silver bands were 

 very evident. Actually their color is very changeable. One struck with the grains 

 became at once almost colorless, and another, shocked by dynamite, showed 

 irregular red blotches on a silvery background. 



A striking feature of this fish is its great lustrous eye, which in specimens 200 

 to 225 mm. in length may be 25 mm. in diameter, and amply justifies the popular 

 name, glass-eyed snapper. 



Tropical Atlantic, northward to Florida; probably also in the Pacific. 



W. H. L. 



Priacanthus arenatus Cuvier and Valenciennes 



The habitats of Priacanthus arenatus and P. cruentatus seem quite distinct. 

 The former was not taken in the shallows with P. cruentatus, but exclusively in 

 the 12-fathom channels within the Tortugas group, and outside down to about 

 45 fathoms. The largest specimen secured was 310 mm. long. W. H. L. 



1 Since the publication of the description of Rhegma brederi, my attention has been called 

 to the fact that George S. Myers (Smithsonian Misc. Coll., vol. 91, no. 23, 1935, p. 2) has 

 stated that Rhegma is a synonym of Pscudogramnms, a genus based on an East Indian 

 species. No data are offered in support of the statement. — S. F. H. 



