Population genetic structure and social kin associations of franciscana dolphin, Pontoporia blainvillei.
We investigated population and social structure of the franciscana dolphin, Pontoporia blainvillei, an endemic and the most endangered cetacean of the southwestern Atlantic Ocean. We analyzed samples from the Rio de la Plata estuary obtained in Uruguayan waters and from the Atlantic Ocean obtained in both Uruguayan and Brazilian waters. Mitochondrial and microsatellite DNA markers were used to study differentiation between the estuary and the ocean and the association between kinship and social group structure. Although multilocus analyses suggested that franciscanas are structured into 2 subpopulations (K = 2, divergence among clusters: F(ST) = 0.06, P = 0.002; R(ST) = 0.3, P = 0.001), mitochondrial markers did not support such divergence (F(ST) = 0.02, P = 0.12; Ф(ST) = 0.06, P =0.06). However, these units are not entirely segregated geographically. Regarding social structure, some groups are composed by first-order related individuals (R ≥ 0.5, P < 0.5). Overall, the data suggest that matrilines could be the social unit in this species. We argue that the divergence found could be associated to local adaptation and social structure, resulting from either feature leading to a recent divergence or reflecting equilibrium between local differentiation and gene flow. This evidence supports considering franciscanas from the Rio de la Plata estuary a discrete management unit.
Departamento de Ecología y Evolución Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay. paula.costa.urrutia@gmail.com
Paula
P
Costa-Urrutia
Carolina
C
Abud
Eduardo R
ER
Secchi
Enrique P
EP
Lessa
D000818:Animals; D001267:Atlantic Ocean; D001499:Bayes Theorem; D001938:Brazil; D004289:Dolphins / Q000235:genetics*; D056727:Endangered Species; D005260:Female; D040342:Genetic Structures; D014644:Genetic Variation; D006239:Haplotypes; D008297:Male; D008390:Markov Chains; D018895:Microsatellite Repeats; D008928:Mitochondria / Q000235:genetics; D009010:Monte Carlo Method; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D058974:Phylogeography; D012726:Sexual Behavior, Animal; D012919:Social Behavior; D014583:Uruguay