St. Williams et Jah. Benzie, GENETIC CONSEQUENCES OF LONG LARVAL LIFE IN THE STARFISH LINCKIA-LAEVIGATA (ECHINODERMATA, ASTEROIDEA) ON THE GREAT-BARRIER-REEF, Marine Biology, 117(1), 1993, pp. 71-77
Gene flow between populations of the asteroid Linckia laevigata (Linna
eus) was investigated by examining over 1000 individuals collected fro
m ten reefs throughout the Great Barrier Reef (GBR), Australia, for ge
netic variation at seven polymorphic enzyme loci. Despite geographic s
eparations in excess of 1000 km, Nei's unbiased genetic distance (0 to
0.003) and standardised genetic variation between populations (F(ST))
values (mean 0.0011) were small and not significant. Genetic homogene
ity among L. laevigata populations is consistent with the long-distanc
e dispersal capability of its 28 d planktonic larval phase, and is gre
ater than that observed for other asteroid species, including another
high-dispersal species, Acanthaster planci, which has a 14 d larval ph
ase. Variation within populations was also higher than previously reco
rded for asteroids (mean heterozygosity = 0.384; number of alleles per
locus ranged from 5.1 to 6.0 in each population). Among asteroids, di
spersal ability is positively correlated with gene flow and levels of
variation, and negatively correlated with levels of differentiation.