Consequences of the historical demography on the global population structure of two highly migratory cosmopolitan marine fishes: the yellowfin tuna (Thunnus albacares) and the skipjack tuna (Katsuwonus pelamis)

• Published in: BMC evolutionary biology 2005-02, Vol.5 (1), p.19-19, Article 19
• Main Authors: Ely, Bert, Viñas, Jordi, Alvarado Bremer, Jaime R, Black, Donna, Lucas, Luciano, Covello, Kelly, Labrie, Alexis V, Thelen, Eric
• Format: Article
• Language: English
• Subjects: Alleles; Analysis of Variance; Animals; Atlantic Ocean; Base Pair Mismatch; Cytochromes b - genetics; DNA, Mitochondrial - genetics; Evolution, Molecular; Gene Frequency; Genetic Variation; Genetics, Population; Katsuwonus; Marine; Models, Genetic; Pacific Ocean; Pelamis; Polymorphism, Restriction Fragment Length; Population Density; Species Specificity; Thunnus albacares; Tuna - genetics
• ISSN: 1471-2148; 1471-2148
• DOI: 10.1186/1471-2148-5-19

Yellowfin and skipjack tuna are globally distributed in the world's tropical and sub-tropical oceans. Since little, if any, migration of these fishes occurs between the Atlantic and Indo-Pacific Oceans, one might expect to see genetic differences between sub-populations in these ocean basins. However, yellowfin and skipjack tuna have extremely large population sizes. Thus, the rate of genetic drift should be slower than that observed for other tunas. Low levels of genetic differentiation were observed between Atlantic and Pacific samples of yellowfin tuna. In contrast, no genetic differentiation was observed between Atlantic and Pacific samples of skipjack tuna. Much lower levels of genetic differentiation were found among sub-populations of yellowfin tuna compared to those observed for other large tunas, probably due to the large population size of yellowfin tuna. Since skipjack tuna appear to have even larger population sizes, it is not surprising that no genetic differentiation was detected between Atlantic and Pacific samples of these fish.