174 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. VII. 



for food. In this way a species of fish (the Serica), worthless as food 

 for man, and another species (the Pescadito), too small to ever become 

 a desirable food fish, could probably be converted into good food 

 fishes. 



In the Pacific Slope rivers of Guatemala there are no Mojarras 

 which strictly feed on small fishes, and none larger or better than the 

 one now found in the lake. The largest one (Cichlasoma trimacu- 

 latum) could easily be introduced into the lake. Its introduction 

 would, to some extent, increase the food fish supply of the lake and 

 its presence there would do no harm. 



In the Rio Montagua and in Lake Isabel is a large Mojarra (Cich- 

 lasoma motaguense) which feeds mostly on small fishes. After the 

 completion of the Guatemala Northern Railroad the introduction of 

 this fish into the lake could be easily accomplished. It is a larger 

 species than the Mojarra which now lives in the lake. 



The Robalo (Centropomus nigrescens] and the Pepemechin (Philyp- 

 nus dormitor) are food fish of some value. These are both found in the 

 Pacific Coast streams of Guatemala. Concerning the value of these 

 fishes as food or game fishes I know almost nothing. The Pepemechin 

 is quite common in the lakes of Nicaragua, and is sold in the markets 

 there for about the same price as is the Mojarra. 



The Large-mouth Black Bass, which is found in all of the streams 

 and lakes of the eastern United States, from Lake Superior to Tampico, 

 Mexico, is a most excellent game and food fish. It feeds almost alto- 

 gether on small fishes. Its flesh is firm and better flavored than that 

 of any of the Mojarras or other fishes above mentioned. This fish is a 

 great favorite with sportsmen, who fish with hook and line for pleasure. 

 So highly prized is it in the United States, that it has been introduced 

 into many of the western lakes and streams. The rate of growth of 

 the Large-mouth Black Bass varies much in different localities. Indi- 

 viduals in some of our United States hatching stations are known to 

 reach a weight of two to eleven pounds when two or three years of age. 

 In lakes and streams in the southern United States this fish is often 

 taken weighing 6 or 8 pounds, while individuals are not uncommon 

 weighing 20 pounds or more. It grows larger and grows more rapidly 

 in the waters of our southern states than farther north. In these 

 southern waters it feeds during most of the year. During the winters 

 in the northern portion of the United States the lakes and rivers become 

 covered with ice, and the water in them under the ice is so cold that 

 fishes become inactive and do not eat. So there is a period of from 

 2 to 4 months that fishes have no chance to grow. The water in 

 Amatitlan is always warm enough to prevent this period of inactivity, 



