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 gen etic relatedness within localized assemblages of the intertidal isopod , laera albifrons (Crustacea: Isopoda). This isopod has marsupial deve lopment, restricted adult vagility and specific habitat preferences, w hich will tend to isolate groups of animals on a shore and can potenti ally maintain the integrity of broods after release from the mother. T otal genomic DNA was extracted from six individuals from each of ten ' rock-populations' in the South Wales area, restricted with RsaI, AlulI I and HaeIII endonucleases, and probed using a (TCC), oligonucleotide probe. Band-sharing analysis of the fingerprint patterns indicated sig nificantly higher genetic relatedness within rock-populations (mean wi thin rock-population band-sharing value = 0.374 +/- 0.023 SE) than bet ween (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 si gnificance of such findings, in terms of the potential for localized i nbreeding and population genetic structure, is discussed.