Hybridization and genetic characterization of sea turtles in Alagoas, northeastern Brazil

• Published in: Marine biology Vol. 170; no. 2; p. 14
• Main Authors: Almeida, João P. F. A., Marques, Oscar K. L., Mott, Tamí, Santos, Robson G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-02-2023; Springer; Springer Nature B.V
• Subjects: Analysis; Aquatic reptiles; Biomedical and Life Sciences; Caretta caretta; Deoxyribonucleic acid; DNA; Freshwater & Marine Ecology; Genetic aspects; Genetic diversity; Genetic variation; Geographical distribution; Haplotypes; Hybrid animals; Hybridization; Hybrids; Identification and classification; Life cycle; Life cycles; Life Sciences; Marine & Freshwater Sciences; Marine biology; Methods; Microbiology; Migrations; Migratory species; Mitochondrial DNA; Nesting; Ocean basins; Oceanography; Original Paper; Population genetics; Population structure; Reptiles & amphibians; Sea turtles; Stranding; Turtles; Zoology; Brazil; Green turtles; Hybrids; Population genetics; Hawksbills; Loggerheads; Olive ridleys
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-022-04168-y

Sea turtles are migratory species with wide geographical distributions, usually spanning multiple countries. This characteristic, along with their complex life cycle, makes sea turtle conservation challenging. In Brazil, continued monitoring and recent studies have advanced the knowledge of sea turtle genetic composition and population structure. Some of these studies have shown that hybridization is highly frequent in certain regions along the Brazilian coast, despite being relatively rare globally. Here, we investigate the hybridization and genetic diversity of sea turtles in nesting and feeding grounds in the state of Alagoas, northeastern Brazil, using the control region of mitochondrial DNA and three nuclear loci. We were able to identify hybrids between four sea turtle species, but mainly between
Caretta caretta
and
Eretmochelys imbricata
and
C. caretta
and
Lepidochelys olivacea
. Most hybrids were readily identified using morphology and mitochondrial DNA, but some were only detected with nuclear DNA. Apart from hybrids, the genetic profile of each species was congruent with previous studies in Brazil. However, one stranded
E. imbricata
had a haplotype (Ei-IP17) and nuclear allele typically found in the Indo-Pacific, suggesting long distance migration for this species. Our results indicate that hybridization events might be even more geographically spread along the coast of Brazil and provide evidence of the connection between
E. imbricata
from the Atlantic and Indo-Pacific Ocean basins.