Fishes of the JVestern North Atlantic 29 



necessarily follow the outer coast for at least the major part of their journeys. To reach 

 Bermuda, as a few certainly do from time to time, they must cross at least 600 miles 

 of open ocean. To judge from the latitudinal limits within which they are year-round 

 residents and from the summer-winter temperatures of the Carolinian waters that they 

 visit during the warm half of the year, the lower thermal limit to their normal range is 

 probably about 16— i8°C (60— 65° F); the upper limit may even be as high as 30° C 

 (86° F).' 



P. pectinatus^ like its relatives, obtains its prey of various small animals chiefly by 

 stirring the mud with its saw, and it may often be seen while so employed. The motion 

 of the saw is described by an eyewitness as principally backward and forward.** But 

 they are recorded also as playing havoc among schools of small mullets and clupeoids, 

 slashing sidewise at them with their saws and devouring the wounded victims. They bite 

 a hook freely if it is baited with fresh fish. 



The fact that young are abundant off Texas, with specimens of three feet or smaller 

 being much more plentiful than larger adults both along the west coast of Florida 

 and in the Indian River on the east coast, is good evidence that large numbers of young 

 are born at least that far northward, as well as along the coasts of British and French 

 Guiana*^ to the southward by similar evidence. The presence of small ones in greater 

 numbers than adults up the St. Johns River makes it likely that young are not only 

 produced in fresh water but that they thrive there. But there is no reason to suppose 

 that any young that may be produced by stray females north of Florida would survive 

 the cold of the succeeding winter. 



Gravid females, with embryos far advanced in development, have been taken in 

 southern Florida waters in April and in July, and small free-living specimens have been 

 caught there in January, suggesting that the young are set free in that region from 

 late spring through the summer, and perhaps through the autumn. The presence of 

 "young" specimens in abundance off southern Texas in May and June'" and in July 

 near Galveston'^ is in line with this conclusion, for it is not likely that any born there 

 in autumn would grow much during the first winter. Farther south, where the seasonal 

 range of temperature is narrower and where the winter temperatures are considerablv 

 higher, it is likely that young are produced throughout the year. 



It has been suggested that the period of gestation is about one year," but available 

 information is not sufficient to establish this point. 



Numerical Abundance. The Common Sawfish is so plentiful in Florida waters that 

 an eyewitness writes of seeing hundreds of them, "big and little,"'^ on the west coast 

 of the peninsula, and one fisherman reports the accidental capture of 300 in his nets 

 in the Indian River in a single season."* Many small ones are caught by fishermen 



68. Henshall, Bull. U.S. Fish Comm., 9, 1S91: 372. 



69. Miiller and Troschel, in Schomburgk, Reisen Brit. Guiana, 3, Fauna Flora Brit. Guiana, 1848: 642; Puvo, Bull. 

 Soc. Hist. nat. Toulouse, 70, 1936: 89. 



70. Baughman, Copeia, 1943: 45. 71. See Study Material, p. 13. 



72. Nichols, Bull. Amer. Mus. nat. Hist., 37, 1917: 876. 73. Henshall, BuU. U. S. Fish Comm., 14, 1S95: 210. 



74. Evermann and Bean, Rep. U.S. Comm. Fish. (1896), 1898: 239. 



