EFFECTS OF TEMPERATURE 



No studies have been made on the influence of 

 temperature on the life and distribution of this 

 wliite shrimp. The geographical distribution and 

 the fact that tlie densest population is in the Gulf 

 of Venezuela-Lake Maracaibo complex indicate 

 that P. schmitti is a warm-water species. White 

 shrimp, however, are found as far soutli as Laguna 

 (lat. 28°29' S.), Brazil, in water influenced by the 

 Falkland Current. 

 EFFECTS OF SALINITY 



Among the sympatric Penacu-s, the young P. 

 schmitti seems to have the greatest preference for 

 low-salmity water. Da Silva (1965) stated that 

 the white shrimp is by far the most abundant 

 species in Baia de SejDetiba, Brazil, where the 

 salinity is very low because about a dozen rivers 

 flow into it. In western Venezuela, white shrimp 

 are most abundant in the low-salmity water of 

 Lake Maracaibo and in the southwestern part of 

 the Gulf of Venezuela, which has the lowest 

 salinity in the area. In contrast, white shrimp 

 witliin the Gulf of Venezuela are absent from the 

 Golfete de Coro, where the salinity is extremely 

 liigh because of intense evaporation. 

 ENEMIES AND DISEASES 



No detailed study of P. schmitti predators has 

 been undertaken. It is, however, well established 

 that Penaeus shrimp in general are an important 

 food of various species of carnivorous fislies and 

 various other animals. My examination of the 

 stomach contents of difi^erent snapiDei-s (Lutjani- 

 dae) showed that white shrimp made up a high 

 percentage of their food. Xikolic and Kuiz (in 

 press) reported white shrimp in the stomach of a 

 stingray "lebisa,'" and also in stomachs of por- 

 poises. White shrimp are also camiibalistic, like 

 other Penaeus. 



Specimens have been found with black colora- 

 tion, apparently suffering from "black spot" 

 caused by a microsporidian sporozoan (Ewald, 

 1964, 1965c). 



Commercial Importance 



P. schmitti is commercially important in Cuba, 

 the Caribbean waters of Central America, Colom- 

 bia, and especially in Venezuela. It is also exten- 

 sively fished commercially along the coast of 

 Brazil. Cuba has a fishery for white shrimp in the 

 Gulf de Guacanayabo and along the southern coast 

 of Camagiiey and Las Villas to Bahia de Cien- 



fuegos. In Guatemala, small quantities of white 

 shrimp are caught at Lago Izabal (Lindner, 1957) 

 and in the western portion of Bahia de Amatique 

 (Croker, 1967). The only important fisheries for 

 white shrimp in Central America are in Honduras 

 and Nicaragua. In 1965, Honduras shrimp exports 

 to the United States (which represent almost the 

 entire production) amounted to 740,270 kg. (heads- 

 off ) ; * practically all shrimp in Honduras are 

 caught on the Caribbean Coast, and Loesch (1962) 

 estimated that P. schmitti accounts for about half 

 of the catches made there. In Nicaragua fishing for 

 white shrimp, although seasonal, is highly pro- 

 ductive; the composition of the production is not 

 known. In Colombia the yoimg are taken com- 

 mercially in the lagoons near the mouth of the 

 Eio Magdalena, and adults are caught in tlie vi- 

 cinity of Cartagena (Alejandro Londoho, personal 

 communication) . 



The greatest fishery by far is in western 

 Venezuela. According to Ewald (1965c), in 1964 

 the total shrimp production in Lake Maracaibo- 

 Bahia de Tablazo, Gulf of Venezuela, amounted to 

 4,249,581 kg., and white shrimp made up 70 per- 

 cent of the shrimp caught in Lake Maracaibo and 

 50 percent of that caught in Bahia de Tablazo. In 

 1965 catches in this area amounted to 7,242,130 kg. 

 ( according to Croker, 1967, "weights are mostly in 

 lieads-off equivalents although shrimp for the 

 domestic market are probably recorded as heads- 

 on"). In the coastal lagoons to the east, white 

 shrimp support several small fisheries (Davant, 

 1963; Khandker, in press) and appear to be scarce 

 in the shallow waters of Guyana, Surinam, and 

 French Guiana, where only small qmintities are 

 caught. 



P. schmitti, as stated earlier, is abundant in the 

 waters of Brazil. It is taken commercially in or 

 wlien leaving the estuarine nursery grounds from 

 Bel em along the coast to Sao Luis, and also at 

 Parnaiba, Natal, Recife, and in Salvador. In east- 

 ern Brazil, camariio legitimo makes up part of the 

 commercial catches from Rio Doce to Cabo Frio 

 and Baia de Guanabara. The most important 

 fisheries for this shrimp in Brazil are those in 

 Baia de Sei^etiba (da Silva, 1965) and in the la- 

 goons along the coast of the States of Sao Paulo 

 (Sadowski and Radasewski, 1960; Braga, 1962), 

 Parana and Santa Catarina (Richardson and 

 Moraes, 1960;Tremel et al., 1964; Tremel and Mis- 



■' All exports figures cited here for Latin America should bo 

 understood to include only "heads-off" estimates. 



498 



U.S. FISH AND WILDLIFE SERVICE 



