FISHES OF CHESAPEAKE BAY 
63 
The species is rare in Chesapeake Bay, where it is occasionally caught in the most southern 
parts. The fishermen do not seem to have a distinctive name for the animal, as those who saw the 
specimen merely called it a “ray.” The species is readily recognized by its smooth, soft skin, 
dark brown color, broad disk, which is straight or slightly concave in front of eyes, and by the large 
caudal fin. 
The torpedo is said to reach a weight of 200 pounds, and a specimen as heavy as 170 pounds 
has been recorded from Massachusetts Bay (Bigelow and Welsh, 1925, p. 69). A specimen has 
been recorded from Cape Lookout, N. C., which was 60)^2 inches in length and weighed 125 pounds. 
It has long been known that the torpedo is capable of emitting strong electric shocks from 
large electric organs situated on each side just back of the head, a shock from a large fish being 
sufficient to knock a man down. 
Little is known of the feeding habits of this ray along our coast, but Day (1880-1884, p. 331) , 
working with European specimens, records from the stomach of one fish a 2-pound eel and a 1-pound 
flounder and from another a 4 or 5 pound salmon, all of which, he believes, may have been killed 
by the electric organs of the fish. 
The species is viviparous, but little is known of its breeding habits. 
Habitat . — Tropical and temperate parts of the Atlantic Ocean, from Maine to Cuba on the 
American coast and from the coasts of Great Britain to Madeira, including the Mediterranean 
Sea, on the European coast. 
Chesapeake localities. — (a) Previous records: “Said to occur very rarely in the region near the 
entrance of Chesapeake Bay.” (Uhler and Lugger, 1876). (5) Specimens seen or preserved 
during the present investigation: One large female, about 4 feet long, taken in a pound net 
in Lynnhaven Roads, Va., on May 25, 1922. 
Family XII.— DASYATIML. The sting rays 
Body, head, and pectorals depressed, together forming a broad disk; the pectorals very broad 
and united around the snout; no supporting cartilage in snout; tail distinct from the disk, either 
long or short, and usually bearing one or more strong, serrated spines; spiracles large and near the 
eyes; skin smooth, or rough and with spines or tubercles, or both. The species are viviparous or 
ovoviviparous. The family contains numerous genera and species. Only two genera are repre- 
sented in the Chesapeake Bay fauna. 
KEY TO THE GENERA 
a. Tail long and slender, whiplike, bearing one or more strong, serrated spines; disk more or less 
quadrangular to circular, not much broader than long Dasyatis, p. 63 
aa. Tail short, the spine present or absent; disk much broader than long Pteroplatea, p. 67 
14. Genus DASYATIS Rafinesque. Sting rays 
Disk more or less quadrangular to circular, very strongly depressed; snout more or less promi- 
nent; tail long, whiplike, with one or more strong, serrated spines, with or without dermal fin 
folds or keels on the median line above, below, and behind the caudal spines; without lateral folds 
on the base; skin usually more or less spiny in adults; teeth small, paved. 
KEY TO THE SPECIES 
a. Tail without a dermal fin fold above, a rather broad fold below, its length more than twice the 
length of the disk; disk broader than long, its length about 1.25 in its width centrura, p. 64 
aa. Tail with a dermal keel or fin fold above and below, its length less than twice the length of 
the disk. 
b. Tail with a low dermal keel above and a rather broad fold below; the color of the folds black; 
the disk quadrangular, its length about 1.2 in its width; middle of forehead with a small; 
round, light-colored spot americana, p. 64 
49826—28 5 
