Phylogeography of the intertidal spider Desis Martensii L. Koch (Araneae: Desidae)

Abstract

<P>DESIS MARTENSII IS A REPRESENTATIVE FROM THE POORLY-STUDIED SPIDER GENUS DESIS, MEMBERS OF WHICH ARE UNIQUE IN BEING TRUE SPIDERS THAT ARE COMPLETELY ADAPTED TO LIVING IN INTERTIDAL ZONES. ALTHOUGH D. MARTENSII WAS ORIGINALLY FOUND IN NEW HARBOUR, IN THIS STUDY, I FOUND THAT IT IS DISTRIBUTED IN THE INTERTIDAL ZONES IN 10 LOCALITIES (EIGHT FROM SINGAPORE AND TWO FROM MALAYSIA). I ALSO INVESTIGATED THE GENETIC VARIATION IN THE MITOCHONDRIAL DNA SEQUENCES CYTOCHROME OXIDASE SUBUNIT I, NADH DEHYDROGENASE SUBUNIT 1, TRNA, AND LARGE-SUBUNIT RIBOSOMAL RNA (16S) AND FOUND A LACK OF PHYLOGEOGRAPHIC STRUCTURING, WITH THE GENETIC VARIATION CONTRIBUTED MOSTLY BY INTRA-POPULATION RATHER THAN INTER-POPULATION DIFFERENCES. I PROPOSE THAT THE GEOGRAPHICAL DISTRIBUTION OF D. MARTENSII IS LIKELY DUE TO INCOMPLETE LINEAGE SORTING, RATHER THAN ONGOING GENE FLOW. THE ORDER OF FRAGMENTATIONS OF THE POPULATIONS COULD NOT BE INFERRED FROM THIS STUDY DUE TO THE LACK OF A SUITABLE OUTGROUP. </P>