PEARSE FISHES OF LAKE VALENCIA, VENEZUELA 27 



PLANTS: Lebistes reticulatus 87, Astyanax metae 55, Astyanax 

 bimaculatus 52, Curimatus argenteus .28, Plecostomus ple- 

 costomus 21, Gephyrocharax valenciae 15.3, Aquidens pulcher 

 2.5, Hoplias malabaricus .8, Pimelodella metae .2. 



MUD: Chaetostomus pearsei 100, (young Symbranchus mar- 

 moratus from bottom of lake 100), Curimatus argenteus 

 71, Plecostomus plecostomus 54, Rhamdia quelen 30, Syw- 

 branchus mar moratus 22, Pimelodella metae 13, Gephyro- 

 charax valenciae 6.3, Aquidens pulcher 3. 



These lists and the data presented in Table V indicate 

 clearly that bottom sediment, insects, plants, molluscs, and 

 fishes are the most important foods for the fishes of Lake 

 Valencia. Plankton, plant or animal, is not important, but the 

 bottom fauna is a valuable source of food for several species. 

 The fishes feeding on plants are small, abundant species which 

 often themselves serve as food for fish eating animals. The 

 snails and a portion of the immature insects also pass on 

 organic food acquired from plants to predacious animals when 

 they are eaten. The great reservoirs of food available for 

 fishes are the bottom mud (where the organic compounds are 

 derived from plants and to some extent from animals), the 

 aquatic vegetation, and the abundant small animals (snails, 

 insect larvae, etc.) feeding directly or indirectly on plants, mud, 

 and to a less extent on other animals. 



It is probable that this condition is not unusual in lakes, 

 tropical and otherwise. The aquatic vegetation and bottom 

 deposits are usually more important sources of fish food than 

 the plankton. Petersen (1918) has come to the same con- 

 clusions in regard to the ocean. 



