Genetic identification of source populations for an aquarium-traded invertebrate

Increasingly, wildlife managers are turning to molecular genetics to aid in conservation efforts. While such approaches have been applied to large terrestrial and aquatic vertebrate species, their application to other traded organisms has not been extensively explored. Here, we examined the utility of these techniques for identifying source populations of aquarium ornamental invertebrates, using members of the Hawaiian atyid genus Halocaridina as a study system. These shrimps, restricted to anchialine habitats of the Hawaiian Islands, are popular in the aquarium trade due to their ability to survive in hermetically sealed containers for extended periods of time. However, commercial harvesting, coupled with habitat destruction and strong regional endemism, could lead to the depletion/extinction of unique populations. Because the land district of Kona, along the west coast of the island of Hawai'i, has the state's highest concentration of anchialine habitats, we hypothesized that commercially available Halocaridina originated from this region. To test this, mitochondrial cytochrome c oxidase subunit I gene sequences from 96 individuals, obtained from six vendors, were compared with 580 homologous sequences from previous studies covering the known distribution range of Halocaridina. Recovery of identical, regional-specific haplotypes, network analyses and statistical assignment tests identified these commercially acquired specimens as belonging to either the Kona, Ka'u, (western and southern coasts, respectively, island of Hawai'i) or Kina'u (southern coast, island of Maui) genetic groups of these shrimps. Although 39 of the 96 individuals originated from the Kona genetic group as hypothesized, our finding that commercially available Halocaridina are from three genetic groups spanning two islands suggests that other populations also warrant potential management consideration. While this study represents the first application of molecular genetics in identifying source populations of aquarium ornamental species, we feel that these techniques are amenable more broadly as they are dependent on only a few caveats.