Biological invasions with known histories are rare, especially in the sea, and empirical studies of the genetic consequences are even rarer. Fifty-five years ago, the state of Hawai‘i began a remarkable, if unintentional, ‘experiment’ with the introduction of three reef fishes,
Lutjanus fulvus
,
Cephalopholis argus
and
Lutjanus kasmira
. All have since expanded from the initial introduction of 2204 to 3163 individuals; however, historical records show that initially
L. fulvus
remained scarce,
C. argus
had modest population expansion and
L. kasmira
experienced rapid population growth. The consequences of differential population growth rates are apparent in
F
-statistics: Hawaiian
L. fulvus
demonstrate strong and significant haplotype frequency shifts from the founder location (
F
ST
= 0.449),
C. argus
shows low but significant differentiation (
F
ST
= 0.066) and
L. kasmira
is nearly identical to the founder location (
F
ST
= 0.008). All three species had higher mtDNA diversity in the introduced range, which can be explained by multiple sources for
L. fulvus
and
L. kasmira
, but not for
C. argus
. We conclude that lag time before population expansion, in conjunction with genetic drift, has defined the genetic architecture of these three species in the introduced range.
Coming out of the starting blocks: extended lag time rearranges genetic diversity in introduced marine fishes of Hawai‘i
