Genetic relatedness in two Southern sea lion (Otaria flavescens) rookeries in the Southwestern Atlantic

SZAPKIEVICH, V.B.; CAPPOZZO, H.L; CRESPO, E.A.; BERNABEU, R.O.; COMAS, C; MUDRY, M.D.

ZEITSCHRIFT FUR SAUGETIERKUNDE-INTERNATIONAL JOURNAL OF MAMMALIAN BIOLOGY

Urban & Fischer Verlag

Lugar: Munich; Año: 1999 vol. 64 p. 246 - 250

0044-3468

In order to test genetic differences between two rookeries of southern sea lions  (Otaria flavescens), blood samples were taken from Punta Norte (PN)  (Península Valdés, Argentina) and Isla de Lobos (IL)  (Maldonado, Uruguay), distant 1300 km  each other. Blood samples  were surveyed electrophoretically for protein variation. Nine blood protein systems encoded 10 loci  were screened, nine of which were monomorphic. Only transferrin (TF) was polymorphic for both sea lions rookeries. The allele TF2 was the most frequent in the samples of both populations. The genetic  variability found  was H= 0.003 for PN and H= 0.034 for IL which resulted  in both extremes of previous studies for pinnipeds. The low genetic variability exhibited at PN was consistent with the degree of exploitation of the species that  took place there during the present century.  The  Nei  distance  between  PN  and IL  was D= 0.004, one of the lowest values found for conespecific mammal populations. The high number of  monomorphic loci and  the low genetic distance between both rookeries, the hypothesis of a single population could not be rejected. The few data available from mark-recapture studies also support this point of view.