Most phylogeographic studies in Taiwan show that the Central Mountain Range is a major geographic barrier to vertebrates inhabiting low-elevation areas. In this study, we choose to investigate the widely distributed giant wood spider Nephila pilipes (Fabricius, 1793) to determine if their population genetic structure also shows an east-west differentiation pattern resembling those of terrestrial vertebrates studied so far. Mitochondrial cytochrome oxidase I (COI) was used as a genetic marker, and its partial sequence was determined in 189 specimens collected from 24 localities in the Ryukyu Islands, Taiwan, and mainland China. The 617-base partial sequence of COI was determined from DNA extracted from the leg muscle, and 11 haplotypes were identified from all specimens examined. Neighbor-joining (NJ) and maximum parsimony (MP) methods were used to construct phylogenetic trees using N. clavata Koch, 1877 and N. antipodiana (Walckenaer, 1841) as outgroups. Results from both methods indicate that N. pilipes populations can be separated into 3 major lineages: group A (haplotypes EA, RK, CN2, CN4, CN5, and CN6), B (haplotypes TW1, TW3, CN1, and CN3), and C (TW2). Group A consists of most specimens from 23 localities. Group B consists of specimens from southeastern China and northwestern Taiwan. Group C consists of a few specimens from a single locality in northeastern Taiwan. The percentage sequence differences from pairwise comparisons of all haplotypes ranged between 0.2% and 3.5%. Within-region nucleotide diversity (π) ranged between 0.0% and 0.57%. The EA haplotype was the main component of all populations, and haplotypes in different Taiwanese populations were not structured geographically. Haplotypes TW1, 2, or 3 were sporadically distributed and could only be found within a few populations. These results indicate that a high level of gene flow exists among different populations of N. pilipes in Taiwan, and therefore the Central Mountain Range does not seem to be a major geographic barrier to this spider.
|Number of pages||11|
|Publication status||Published - 2004 Jan 1|
All Science Journal Classification (ASJC) codes
- Animal Science and Zoology