64 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
7. Pristis pectinatus Latham. Common Saw-fish; “Pez Sierra.” 
First dorsal over ventrals; second dorsal scarcely smaller than first; no lower caudal lobe. Saw 
with 24 to 32 pairs of teeth, the posterior farther apart than the anterior. Found in the tropical seas 
north to West Indies and Florida; abundant in the Gulf of Mexico, ascending the Lower Mississippi. 
The species probably reaches a length of 20 feet. Not obtained by us, but included on the authority 
of Professor Poey. 
The saw-fish is abundant in Indian River, Florida, where it is permanently' resident. It is held in 
much dread by the commercial fishermen on account of the damage which it does by becoming 
entangled in their nets. The larger ones tear or cut the nets so seriously as to render them valueless, 
while the smaller ones become entangled and can only be removed with great difficulty. Those seen 
in Indian River usually do not exceed 3 feet in length, the saw included, but very large ones are 
occasionally taken. It is said that one caught near Eau Gallie in October, 1895, was 12.5 feet long and 
weighed 425 pounds. The largest reported by fishermen were 16 or 17 feet long. 
Some interesting information concerning the young of the saw-fish is recorded. Mr. F. B. Everett 
says that from a large female saw-fish he took a number of young which swam away when placed in 
the water. The “saws” were enveloped in a membrane which soon disappeared in specimens left to 
dry in the sun, and the teeth became visible. Mr. Stypmann, of Stuart, Fla., took 18 or 20 young from 
a saw-fish about the 1st of July. The “saws” were well developed, but they, like the teeth, were soft 
like leather. There is some variation in the number of teeth on the saw, and there is usually one more 
tooth on one side than on the other. From a large number counted it appears that the usual numbers 
are 25 and 26, respectively. 
Another species of saw-fish ( Pristis perrotteti Valenciennes) was described in 1838 from the Senegal 
River, on the west coast of Africa. This is said to occur in the West Indies, and the saw-fish from the 
Pacific coast of America north to Mazatlan has been identified with it. The Pacific coast species, 
however, is now regarded as distinct, and has been named Pristis zephyr eus Jordan & Starks. No 
direct comparison has been made between specimens from the west coast of Africa and the West 
Indies, and it may be that there is but the one species in the West Indies. 
Pristis pectinatus Latham, Trans. Linn. Soc., II, 278, 1794, “in the ocean”; Poey, Fauna Puerto-Riquena, 349, 1881; 
Stahl, 1. c., 81 and 167, 1881; Jordan & Evermann, l.c.,60, 1896. 
Pristis granulosa Bloch & Schneider, Syst. Ichth., 352, 1801, Havana; after Parra. 
Pristis mississippiensis Rafinesque, Ichth. Ohi., 80, 1820. Lower Mississippi River 
Pristis megalodon DurmSril, Elasmobranches, 476, pi. 9, fig. 4, 1870, Cayenne. 
Pristis acutirostris Dumeril, 1. c., 479, 1870, Martinique. 
Family VI. DASYATIDtE. The Sting Rays. 
Disk usually more or less broad than long; pectoral fins uninterruptedly confluent in front, 
forming tip of snout; tail variously formed, usually whip-like, sometimes short and stout, sometimes 
bearing a single dorsal or caudal fin, but never with two dorsals; usually one or more vertical folds 
of skin on the tail, rarely a lateral fold. Tail generally armed with a large, sharp, retrorsely serrate 
spine on its upper surface toward the base; 2 or 3 spines occasionally present. Ventral fins not 
emarginate. Skin smooth or variously prickly or spinous, roughest in adult; no differentiated spines 
on pectorals in males, the sexes being similar. Mouth rather small; teeth small, paved, usually more 
or less pointed or tubercular. Nostrils close together; nasal valves forming a rectangular flap, which 
is joined to upper jaw by a narrow frenum. Spiracles large, placed close behind eyes. Skull not 
elevated, spiracles and eyes superior. Ovoviviparous. 
Found in most warm seas, some of them in the fresh waters of the northern parts of South 
America. Genera about 10; species 50. The large jagged spine on the muscular tail is capable of 
inflicting a severe and even dangerous wound. Only two species of this family are as yet known from 
Porto Rico, though doubtless others will be found. 
a. Tail stout, provided with a rayed caudal fin; no dorsal fin; disk roundish; caudal spine strong Urolophus 
aa. Tail slender, without caudal fin; pelvis without sword-shaped process. (Marine species.) 
Dasyatinje: 
b. Tail whip-like, longer than disk, which is rhomboid or roundish; caudal spine strong Dasyatis, 7 
bb. Tail very short, shorter than the very broad, transversely rhombic disk; caudal spine weak, often wanting. No 
trace of dorsal fin Pteroplatea 
