Fishes of the Western North Atlantic 381 



than anal, as in leucas. Pectoral very nearly as long as head and thus a little longer than 

 in leucas, but of same general shape, a little more than Yi as broad as long, the outer 

 margin nearly straight except near tip, the distal margin a little more deeply concave 

 toward base than in leucas. 



Color. Dark mouse-gray above after preservation in salt, grayish to yellowish white 

 below, with lower surfaces of pectorals dusky at tipsj photographs at time of capture show 

 the lower surface a clearer white, the lower pectoral tips and tip of lower caudal dusky or 

 nearly black. It is said that the bellies of large specimens may have a reddish bronze tinge. 



Size. The fact that the specimens we have seen are immature, although up to 5 

 feet long, is in line with information reaching us from Nicaragua that the average size of 

 those caught around San Carlos is 6 to 6V2 feet. We have a definite report of one of 8 

 feet, and they are rumored to reach 10 feet. One of 4 feet is reported as weighing about 

 50 pounds. Specimens of 62 and 67 inches (1,568 mm. and 1,710 mm.) in the United 

 States National Museum weighed 73 pounds and 98 pounds respectively when caught. 



Develof mental Stages. Embryos have not been seen. 



Remarks. Nicaraguensis was classed by Garman,^"' and more recently by Meek and 

 Hildebrand,'"' as a synonym of milherti, in spite of the fact that firsthand accounts had 

 credited it with a much shorter snout. Actually it is so close to leucas that it is undoubtedly 

 an offshoot of the latter. But the several small differences, enumerated above, seem suffi- 

 cient for retention of a separate name for it, especially since it is the only shark that is 

 known to have adapted itself permanently to life in fresh water. Nor is it astonishing that 

 this should have happened, for leucas has been reported in fresh water far up rivers else- 

 where (p. 341). 



Habits. Very little is known of the habits of this fresh-water shark, except that it 

 comes commonly into very shoal water although it is seldom actually seen at the surface 

 and that it bites very readily on bait of meat or fish. Presumably it feeds on fish, but no 

 precise information is available as to its diet."° Nothing is known about its breeding habits. 



Relation to Man. The fins are valued locally for food, and the livers are sold for 

 their vitamin content. 



It is reputedly a danger to bathers, as well as to any dog that may venture into the 

 lake. And published accounts of its ferocity appear to be well founded, for a correspondent 

 in whom we have full confidence"" reports that he has not only seen an attack on a youth 

 swimming at San Carlos but has heard of actual fatalities at other localities around the lake. 

 Very recently the press has reported attacks on bathers and fishermen at Granada, where 

 one of the victims lost an arm, while another lost his right leg and had his left leg injured."^ 



Range. Known definitely only from Lake Nicaragua, its tributaries and outlet."^ 



107. Mem. Harv. Mus. comp. ZooL, jd, 1913: 133. 108. Field Mus. Publ. Zool., 15 (i), 1923: 38. 



109. For an account of the fishes of Lake Nicaragua, see Meek (Field Mus. Publ. Zool., 7 [4], 1907: 95-132). 



1 10. Capt. W. B. Bunker. 



111. In the Diario Nuevo, San Salvador, for April 24, 1944. 



112. Jordan, Evermann and Clark (Rep. U.S. Comm. Fish. [1928], 2, 1930: 16) include "Bay of Panama" in its 



