PARENT SESSION
Tuesday, August 8, 5:00-6:30 pm
Poster Session 10 - Genetics, evolution, and paleoecology
Exhibit Hall, Ballroom Level, Cook Convention Center
A preliminary molecular analysis of the Theraphosid genus Aphonopelma and its implications on dispersal patterns and current taxonomy.
Hamilton, Donna*,1, Bell, Margaret2, McIntyre, Nancy 1, Densmore, Llewellyn1, 1 Texas Tech University, Lubbock, Texas, USA2 Victoria College, Victoria, Texas, USA
ABSTRACT- The Theraphosid genus Aphonopelma belongs to the infraorder Mygalomorphae, a group thought to be relatively primitive and highly conserved morphologically. The genus ranges throughout the southern third of the United States from the Californian coast east to the Mississippi River with 50 recognized species in the US. Adult females and sub-adult males live in subterranean burrows in informal aggregations that may be matriarchal in nature since although some mygalomorphs have been found to disperse by ballooning, theraphosids are not known to do so and this may cause their dispersal distances to be limited in immaturity. Upon maturity, the males disperse, walking from their burrows in search of a mature female, presumably unrelated to the male. The taxonomy of Aphonopelma has to date been completely reliant on morphological data although many of these descriptions can be difficult to apply taxonomically since the descriptions are frequently brief and based on inadequate sample size to account for variation in morphological characters within the populations studied or even between the two sexes present. Several species of Aphonopelma in North America have been described on the basis of a single individual collected. In this work, we tested the validity of the geographical boundaries of Aphonopelma hentzi using the molecular characters of 16S and CO1. By sampling two populations of A. hentzi, one from the northern end of its range in central Missouri and the other population in the southern portions of its range in north-central Texas and comparing the molecular diversity found within the species with that found in a population of a geographically adjacent A. hollyi sampled in the panhandle of Texas we were able to substantiate at least one species. Additionally, the diversity within aggregations was assessed using the mitochondrial markers as well as microsatellite markers to determine whether in fact these aggregations were matriarchal in nature and results to date imply a lack of familial structure within the aggregations.
Key words: dispersal, genetics, spiders