Microsatellite Genetic Characterization of the Humpback Whale (Megaptera novaeangliae) Breeding Ground off Brazil (Breeding Stock A)

Abstract

The Southwestern Atlantic Ocean humpback whales wintering ground (breeding stock A) are distributed along the Brazilian coast (5-23 degrees S), and their main mating and calving ground is in the Abrolhos Bank. We investigated genetic diversity, population structure, and relatedness of individuals sampled from the entire Southwest Atlantic humpback whale population. A total of 275 individuals sampled from 2 subregions (Abrolhos Bank, n = 229 and Praia do Forte, n = 46) were screened for 9 microsatellite loci. This population showed a high level of allelic diversity (A = 12.1) and a high mean observed heterozygosity (H(O) = 0.733). No signal of significant genetic bottleneck was detected in accordance with the mitochondrial DNA data. We find no evidence of temporal (between years) genetic structure as well as no genetic differentiation between whales from the 2 subregions of the Brazilian breeding ground. We observed that the proportion of males and females in this population was approximately 1:1, which differs from the male-biased sex ratio observed in other breeding grounds. The data obtained through this study provided no evidence of kinship associations within social groups. Finally, a female sampled off South Georgia Islands showed a putative parent-offspring relationship with a female off Abrolhos Bank, supporting the migratory link between these 2 areas.

A quarter of a world away: female humpback whale moves 10 000 km between breeding areas

“…Skin biopsy samples were collected off Brazil under licence SISBIO 21489-1 [25]. Molecular sex determination was carried out by polymerase chain reaction amplification followed by TaqI digestion of the ZFX/ZFY region of the sex chromosomes [26,27].…”

First circumglobal assessment of Southern Hemisphere humpback whale mitochondrial genetic variation and implications for management

“…Given the northward extension of the breeding area, and the presence of private haplotypes found within BSG that may be of northern origin, levels of isolation for BSG observed here might decrease if Northern Hemisphere populations were also considered in the analysis (Anderson 2013). In the austral summer and fall, whales from BSG migrate south to feeding areas in the Fueguian Archipelago, west of the Antarctic Peninsula (Zerbini et al 2006, Cypriano-Souza et al 2010, and recently also to the Corcovado Gulf, in the northern Chilean Patagonian channels (Acevedo et al 2013). Photoidentification indicates philopatry and an absence of movements among the 3 feeding areas (Acevedo et al 2013), possibly due to high and stable densities of krill in the vicinity of the Antarctic Peninsula (Nicol et al 2000).…”

“…BSA, located off Brazil, shows relatively high diversity and no genetic substructure within the stock in a data set of 9 microsatellites (Cypriano-Souza et al 2010), despite direct connectivity (of 1 individual) recorded between BSA and the distant BSC in the western Indian Ocean and song similarity between BSA and BSB in the eastern South Atlantic (Darling & Sousa-Lima 2005, Stevick et al 2011. In contrast, BSB shows evidence of complex population Table 1.…”

Cetacean records along a coastal-offshore gradient in the Vitória-Trindade Chain, western South Atlantic Ocean

“…Studies of population structure using DNA and within breeding ground movements in the coast of Brazil suggest there is a limited population substructure within the Brazilian humpback whale population (Cypriano-Souza et al, 2010;Wedekin et al, 2010). These studies, however, only considered genetic samples and photo-identification data from whales sampled near the coast of Brazil.…”