Data from: Population structure and comparative phylogeography of jack species (Caranx ignobilis and C. melampygus) in the high Hawaiian Islands

Members of the family Carangidae are top-level predators and highly prized
food and sport fishes. Although ecologically and economically important,
little is known about the biology of numerous species in the family. This
is particularly true of the jacks Caranx ignobilis and C. melampygus,
which have experienced recent population reductions around the high
Hawaiian Islands due to overfishing. Previous studies have documented
territorial tendencies as well as cases of long-distance excursions in
both species, suggesting populations may exhibit a range of structure at
the genetic level. To explore this possibility, mitochondrial (mtDNA)
ATPase6 and ATPase8 gene sequence variation was assessed from 91
individuals (33 C. ignobilis and 58 C. melampygus) spanning the islands of
Kauai, Oahu, Molokai, Maui and Hawai‘i. While a total of 20 distinct
haplotypes (eight for C. ignobilis; 12 for C. melampygus) were recovered,
no evidence of population structure was found for either species across
the examined geographic range. However, distinct demographic patterns were
identified, implying differing evolutionary histories and/or population
dynamics. Additionally, ~6% of the examined C. ignobilis were C. ignobilis
x C. melampygus hybrids since they harbored mitochondrial haplotypes
typical of C. melampygus. These hybrids contribute to measurable gene flow
between the species and may play a significant role in the evolution of
the genus.