202 Field Columbian Museum — Zoology, Vol. VII. 



CRUSTACEA OF LAKES AMATITLAN AND ATITLAN. 



Two species of larger Crustacea occur in Lake Amatitlan, but 

 one of these, the Freshwater Crab, occurs in both lakes. During 

 the breeding time for these species, they form a considerable 

 amount of the food supply taken from Lake Amatitlan. 



For notes and the identification of these species I am indebted 

 to Miss Mary J. Rathbun, of the Smithsonian Institution, Washing- 

 ton, D. C. 



Family PalaBnioiiidse. Shrimps: Camarons. 



Bithynis jamaicensis Herbst. Camaron. 



The Camaron is a large shrimp which is quite abundant in the 

 Pacific Coast streams of Middle America. It is now quite abun- 

 dant in Lake Amatitlan, but is difficult to capture, except in April, 

 May, and June during its breeding season. This species inhabits 

 fresh waters from Lower California and Texas to Ecuador and 

 Rio de Janeiro. It is also abundant in the West Indies, and 

 wherever found it is much prized as an article of food. This large 

 Shrimp or Camaron does not inhabit Lake Atitlan. The fact 

 that it is abundant in the Pacific coast streams indicates that it 

 is possibly native to Lake Amatitlan, although it is reported to 

 have been introduced there. Lake Atitlan has no outlet, and it 

 also has a very limited fish fauna, and so the absence of this 

 crustacean might be expected. This Camaron is reported as 

 abundant in the west coast rivers of Nicaragua, but is said not to 

 occur in Lakes Managua and Nicaragua; but neither of these 

 lakes communicates with the west coast streams. Except 

 during the spring months, this species is said to go to deep water. 

 At any rate they are seldom seen, or seldom captured, except 

 during the breeding season. As an article of food, this Shrimp 

 is very highly prized. Lake Amatitlan, abundant in breeding 

 season. 



Family l*ofalllOllida^ Crabs; Cangrejos. 



Potamocarcinus guatemalensis Rathbun. Cangrejo. 



This crab is quite abundant in Lake Amatitlan, but like the 

 Camaron is more easily captured during the breeding time, which 



