INTRASPECIFIC GENETIC DIFFERENTIATION IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS) FROM SOUTHERN CALIFORNIA AND THE GULF OF CALIFORNIA

Abstract

Intraspecific patterns of mitochondrial DNA sequence variation were determined among California sea lions (Zalophus califomianus californianus) from three colonies along the Pacific coast of southern and Baja California and one colony in the Gulf of California. We found no variation in 368 base pairs (bp) of cytochrome b sequence among 40 sea lions from these localities, but analysis of 360 base pairs of control region revealed eleven genotypes. The four genotypes found in the Gulf of California population were unique and phylogenetically distinct from those found in sea lions along the Pacific coast. The average sequence divergence between Gulf and Southern California genotypes was 4.3%, suggesting a relatively long period of isolation. However, colonies along the Pacific coast, which are less than 200 km apart, shared mtDNA genotypes, indicating that recent genetic exchange has occurred between them. Therefore, we suggest that regional female philopatry exists in California sea lions. Regional boundaries may be related to oceanic currents or patchiness in the distribution of resources. Further research is needed to better understand the underlying causes of genetic differentiation in the California sea lion.

Phylogenetic Relationships within the Eared Seals (Otariidae: Carnivora): Implications for the Historical Biogeography of the Family

“…There are two exceptions: one OTU each for Z. californians and A. townsendi. Because Maldonado et al (1995) found no variation in 368 bp of the same cytochrome b region of 40 Z. californianus individuals, the combination of the regions from unknown individuals was not considered problematic in this case. The A. townsendi OTU (ATO45) resulted from the control region sequence of ATO4 and cytochrome b sequence of ATO5.…”

“…a Sequenced as part of this study; b Sequenced as part of Wynen et al, 2000; c Genbank (Lento et al, 1997); d Lento, 1995; e Goldsworthy et al, 2000; f Sequenced as part of this study by Rus Hoelzel; g Genbank (Maldonado et al, 1995); h Genbank (Masuda and Yoshida, 1994); i Genbank (Arnason et al, 1995); j Genbank (Arnason and Johnsson, 1992). Genbank accession numbers are listed where relevant; * Overall values presented for ingroup taxa only.…”

Phylogeography and Pleistocene demographic history of the endangered marsh deer (Blastocerus dichotomus) from the Río de la Plata Basin

“…Universal primers Thr-L15910 and DL-H16498 (Kocher et al 1989) were used in PCR reactions to amplify a 601 bp fragment including the 5' domain and the conserved blocks F and E of the control region (Douzery and Randy 1997), following protocols described by Gonza´lez (1997). In addition, a 486 bp fragment of cytochrome b gene was amplified for 44 representative individuals from all localities using primers L14724 and H15149, as described in Maldonado et al (1995). DNA extractions and PCR reactions were performed at the genetic facilities at IIBCE (Uruguay) and at Departamento de Zootecnia, FCAV/ UNESP (Brazil).…”

Vicariance and Dispersal Across Baja California in Disjunct Marine Fish Populations

“…1). These include marine mammals, invertebrates, and approximately 19 species of fishes (Miller and Lea 1972;Present 1987;Maldonado et al 1995;Medina and Walsh 2000;Thomson et al 2000; Table 1). While the concept of disjunction refers to intraspecific geographic separation, in two cases of Pacific Ocean/Gulf of California fishes, species rankings were given to each group.…”