i 9 4i CATALOGUE OF FISHES OF TORTUGAS I2I 



in life, an observation confirmed by Dr. Longley in his notes, whereas the red 

 snapper has a red iris. 

 West Indies, Gulf of Mexico. S. F. H. 



Ocyurus chrysurus (Bloch). Yellowtail 



(Plate n, figure 2; plate 12, figure 1; plate 19, figure 2; plate 32, figure 2) 



Few Tortugas fishes are more numerous than this species, which is found by 

 hundreds among gorgonian thickets and Orbicella heads. In small numbers it 

 has a very wide distribution throughout the group. Throughout the summer the 

 young may be seined in abundance among turtle grass. The yellowtail's range 

 extends from bottom to surface. It is, nevertheless, principally a fish of the middle 

 depths, where it swims, when not feeding, usually 4 to 6 feet from the bottom 

 in 12 to 15 feet of water. 



Its time of feeding is not as closely restricted to the night hours as in other 

 species of its family. Many do feed at night, but individuals may be seen by 

 day following the red goatfish, for example, and competing with Halichoeres 

 Hvittatus for shrimps. Still others may be seen feeding at the surface in the deep 

 water of the lagoon. }en\insia lamprotaenia and other small fishes, shrimps, 

 crabs, stomatopods, and annelids make up its food. 



The trim body of the adult is delicately countershaded. In color it is blue-gray, 

 marked with spots and lines of brassy yellow. Chief among these is the ocular 

 stripe, which widens posteriorly, becomes confluent with others on the caudal 

 peduncle, and spreads finally over the entire surface of the deeply forked caudal 

 fin. The spots are confined to the upper half of the body before the mid-point of 

 the base of the soft dorsal. Below the broad ocular stripe the series of yellow lines 

 become fainter ventrally, and the lower also diminish in intensity as they pass 

 from a comparatively exposed position on the side to the more shaded one be- 

 neath the caudal peduncle. 



In coloration the yellowtail is changeable. Over clean sand fish are lighter in 

 shade than in darker surroundings. Some over light bottom about the Laboratory 

 dock at sunset reduced their yellow to pale straw color. The pattern varies, too, 

 for a blotched phase is sometimes displayed on the reef by individuals at rest 

 close to the bottom. The young show it regularly at night in aquarium tanks, or 

 when hovering near the bottom in shallow dishes by day. 



Brazil to Florida. W. H. L. 



Rhomboplites aurorubens (Cuvier and Valenciennes) 



Three specimens, 140, 150, and 170 mm. long, are included in the collection. 

 The 2 larger ones are without definite locality data. The smallest one was taken 

 south of Tortugas in about 50 fathoms. As this is a rather deep-water species, it 

 is probable that the others were taken in the same general vicinity. 



The 3 specimens are all females with large roe. The smallest, the only one for 

 which the date of capture is known, was caught July 2, 1932. The indication, 

 then, is that spawning takes place during midsummer. 



The following proportions and enumerations are based on the 3 Tortugas 

 specimens, given in order of their size beginning with the smallest one: Head 



