Caracterizacion genetica y morfologica de las poblaciones de Cyprinodon dear-borni (Atherinomorpha: Cyprinodontidae) en Chacopata y Laguna de los Patos, Venezuela / Genetic and morphological characteristics of the populations of Cyprinodon dearborni (Atherinomorpha: Cyprinodontidae) in Chacopata and Laguna de los Patos, Venezuela

Two populations of the fish Cyprinodon dearborni were compared, one from Laguna de Chacopata and the other from Laguna de los Patos, Cumana, Venezuela. The morphometric method of the Box Truss was used; the organisms were photographed with a digital camera. In the images 18 measures were made to each organism, with the MOCHA 1.2 program. The tendencies of morphologic variation among populations were analyzed by main components using STATGRAPHICS 2.0 and SHEAR programs. The first four main components in males and females explained 88 of the total variation. The components two, three and four separate the two populations based on the body form of the animals. For the electrophoretic study, 13 enzymatic systems were analyzed in starch gels. The variation and genetic distance were calculated with the program GENES 2.0. Differences were observed in the systems G6PDH, GPI; ES and GLUD, that which can be used as isoenzimatic markers. Genetic diversity of Chacopata (H = 0.086, p = 0.079) was higher than in Laguna de los Patos (H = 0.029, p = 0.028), but both are within the average in populations of fish. The two populations presented a Nei distance of 0.058. The genetic and morphologic differentiation suggests an incipient process of separation whose causes could be the ecological conditions of their habitat, or processes of vicariant speciation.

Cobre, cadmio y plomo en el pez Cyprinodon dearborni, sedimentos y agua en dos lagunas de Venezuela / Cooper, cadmium and lead in the Cyprinodon dearborni fish, in the sediments and in the water in two Venezuela's lagoons

The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patos lagoon is hypo saline and receives significant wastewater from Cumaná city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C. dearborni from the Chacopata lagoon were: 159.26 +/- 210.68 microg/g for Cu, 44.71 +/- 45.58 microg/g for Cd, and 9.31 +/- 23.34 microg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 +/- 16.30, 19.48 +/- 5.81 and 22.85 +/- 20.00, respectively. In the water column, the metal concentration ranges were: 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.