78 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Figure 34. — Devil ray {Mania birostris), juvenile male, 11 feet 5}i inches wide, Bimini, Bahamas. 



Schroeder. Drawing by E. N. Fischer. 



From Bigelow and 



position of its mouth, which extends across the 

 front of its head instead of being on the under side. 

 Its cephalic fins are about one-half as broad at 

 the base as they are long, with thin lower edges 

 and thick fleshy upper edges and rounded tips, and 

 each arises nearly vertical from the side of the 

 head. When the owner is swimming they point 

 directly forward, but when the ray is feeding, they 

 can be curved inward, one toward the other 

 until their tips nearly meet in front of the mouth. 

 The disc (not counting the cephalic fins) is a little 

 more than twice as broad as long, with tapering 

 outer corners. The tail measured from the 

 cloaca is at least as long as the body from cloaca 

 to front of head and perhaps longer still if not 

 damaged. And it bears a small rounded dorsal fin 

 on its base. Some specimens have been described 

 as having one or two small tail spines close 

 behind the dorsal fins. However, those that we 

 have seen have had none, but a rounded knob in its 

 place, supported by a mass of bony tissue with a 

 minute pointed spur on the upper side that can 

 be felt but does not break the skin. The skin of 

 disc, pelvic fin, and tail is roughened with small 

 tubercles, below as well as above. The mouth is 



very wide, extending across a little more than 

 one-half the whole breadth of the front of the head. 

 And the teeth, the lower jaw only, are minute and 

 very numerous; we counted about 270 series in 

 about 12 to 18 rows or a total of about 4,500 in 

 one specimen about 11}£ feet wide. The gill 

 openings are noticeably long. 



Color. — The upper side varies from reddish or 

 olive brown to bluish slate colored or black, either 

 plain or with various white markings. The lower 

 side is white toward the center of the disc but 

 gray around the margins, and there may be 

 various dark blotches in the region of the gills 

 and on the abdomen. The rear part of the tail 

 is gray. 



Size. — This giant ray matures when about 14 

 to 15 feet wide. They commonly grow to 18 feet 

 or so, and there are recent records of measured 

 specimens 19 feet 8 inches, 21 feet 2 inches, and 

 22 feet wide. One 14 feet wide weighed 1,686 

 pounds, one from the Galapagos Islands, 18 feet 

 wide, 2,310 pounds; and one of 20 feet taken long 

 ago off Venezuela weighed 3,502 pounds. 



General range. — Manta is known in the Atlantic 

 from middle Brazil to the Carolinas and as a rare 



