Measurements 



Based on 18 specimens, 121 to 166 mm. standard 

 length, given as percent of standard lengtli. 

 Preanal 85.0 (83.5-86.7) ; preventral 55.8 (53.8- 

 57.3) ; predorsal 47.7 (46.4-49.1) ; head length 30.6 

 (28.8-33.0) ; snout 10.3 (10.1-10.5) ; eye 9.7 (8.7- 

 10.7) ; maxillary length 5.3 (3.8-5.9) ; depth at 

 dorsal fin 8.6 (7.3-11.0) ; depth caudal peduncle 

 5.1 (4.5-5.5). 

 Description 



Body elongate. Figure 8 shows a regression of 

 body depth on standard length (Y=.069X + 2.43) 

 compared with two closely related species. Great- 

 est depth behind head, tapering little to the caudal 

 peduncle. Figure 9 shows a regression of caudal 

 peduncle depth on head length (Y=.112X + 2.44) 

 compared with two closely related species. Body 

 in cross section in front of dorsal fin usually wider 

 than deep, approximately rectangular. The head, 

 when ^dewed laterally, has its dorsal profile 

 slightly interrupted by the upper margin of the 

 eye; the ventral profile of the head rises gently to 

 the snout. The interorbital space between the 

 supraocular canals flat or barely concave. The 

 dorsal portion of the maxillary lies under the 

 lachrymal. The distal end of the maxillary is mid- 

 way between the tip of the snout and the anterior 

 margin of the orbit. The jaws are broadly rounded, 

 the lower included. The palatine and the head of 

 the vomer bear small, closely spaced, needlelike 

 teeth in a continuous band 2 to 5 teeth wide, about 

 30 on the vomer and 45 on each palatine; no 

 dentary teeth. The ceratobranchial of the fifth gill 

 arch bears 14 small, conical teeth ; two patches of 

 similar teeth, with about 18 on each are found at 

 the anterior end of the fourth suprabranchial. The 

 tongue bears eight strong recurved teeth (descrip- 

 tion of dentition based on a single alizarin speci- 

 men) . The gill rakers are widely spaced triangular 

 flaps ; the longest ones are equal to one-seventh to 

 one-eighth of the interorbital distance. 



The pectoral fin originates on the ventral surface 

 of the body anterior to a line through the hind 

 margin of the opercle. The distance between the 

 inner rays of the pectoral fins is equal to or greater 

 than the least depth of the caudal peduncle. The 

 rays of all fins ai'e broken off short. 



Scales deciduous; the few we have seen lack 

 spines. Lateral scale pockets about 55. 



The peritoneum is densely punctulate with small 



dark chroniatophores. Several specimens have the 

 gut lightly peppered with chroniatophores. Seven 

 to nine pyloric caeca are present in eight speci- 

 mens. The swimbladder begins close to the hind 

 curve of the stomach and extends posteriorly to 

 beyond the origin of the ventral fin. Swimbladder 

 lacking silvery pigment (fig. 5) ; however, we 

 have seen one specimen with an iridescent swim- 

 bladder. 



Pigmentation of adult specimens preserved in 

 formaldehyde solution consists of a dark brown 

 band extending along the upper one-fourth of the 

 body; ventral and parallel to the band is a less 

 darkly pigmented area. These two pigment bands 

 color the entire upper one-half of the body. The 

 dorsum is unpigmented with the exception of a 

 narrow middorsal streak. The throat and breast 

 are peppered with chromatophores, which in some 

 specimens are also scattered at the bases of the ven- 

 tral fins (fig. lOB). In some specimens the peri- 

 toneum shows through the belly as a dark, mid- 

 ventral streak. Some specimens also have some of 

 the scale pockets of the venter outlined in dark 

 pigment. 



Distribution 



A. stewarti has been taken off Nicaragua in the 

 western Caribbean and from Mona Island to Do- 

 minica in the Antilles (fig. 4) . It seems likely that 

 it is widespread in the southern Caribbean. 



Depth distribution ranges from 200 to 310 fm. 

 (366-567 m.) — deeper than the other three Gulf 

 and Caribbean species. A. stewarti does overlap the 

 lower half of the depth distributions of the other 

 three ; however, iit is the only species that has not 

 been taken shoaler than 200 fm. (366 m.). 

 Habits 



We have little information on this species. It 

 has been taken only with a bottom trawl ; however, 

 we have no information on bottom type or tem- 

 perature. Specimens are most often taken singly; 

 however, we have one collection with six fishes. A. 

 stewarti has been taken with georgei and ht'ucei. 

 Name 



Xamed for Stewart Springer in recognition of 

 his numerous contributions to the ichthyology of 

 tlie tropical western Atlantic. 

 Study Material 



All from the Atlantic. Holotype; USNM 202996, 

 144 mm. standard length; Oregon 3565, 14°10' N., 



30 



U.S. FISH AND WILDLIFE SERVICE 



