DETECTION OF HIGH-LEVELS OF GENETIC RELATEDNESS IN ROCK-POPULATIONS OF AN INTERTIDAL ISOPOD USING DNA-FINGERPRINTING

Multi-locus DNA fingerprinting was used to determine the degree of genetic relatedness within localized assemblages of the intertidal isopod, laera albifrons (Crustacea: Isopoda). This isopod has marsupial development, restricted adult vagility and specific habitat preferences, which will tend to isolate groups of animals on a shore and can potentially maintain the integrity of broods after release from the mother. Total genomic DNA was extracted from six individuals from each of ten 'rock-populations' in the South Wales area, restricted with RsaI, AlulII and HaeIII endonucleases, and probed using a (TCC), oligonucleotide probe. Band-sharing analysis of the fingerprint patterns indicated significantly higher genetic relatedness within rock-populations (mean within rock-population band-sharing value = 0.374 +/- 0.023 SE) than between (maximum between rock-population band-sharing value = 0.301 +/- 0.033) and at a level that equates to a relatedness between individuals within rock-populations of slightly below half-sibling status. The significance of such findings, in terms of the potential for localized inbreeding and population genetic structure, is discussed.