Phylogeography of a good Caribbean disperser:Argiope argentata(Araneae, Araneidae) and a new 'cryptic' species from Cuba.
The Caribbean islands harbor rich biodiversity with high levels of single island endemism. Stretches of ocean between islands represent significant barriers to gene-flow. Yet some native species are widespread, indicating dispersal across oceans, even in wingless organisms like spiders.Argiope argentata(Fabricius, 1775) is a large, charismatic, and widespread species of orb-weaving spider ranging from the United States to Argentina and is well known to balloon. Here we explore the phylogeography ofArgiope argentatain the Caribbean as a part of the multi-lineage CarBio project, through mtDNA haplotype and multi-locus phylogenetic analyses. The history of theArgiope argentatalineage in the Caribbean goes back 3-5 million years and is characterized by multiple dispersal events and isolation-by-distance. We find a highly genetically distinct lineage on Cuba which we describe asArgiope butchkosp. n.While theargentatalineage seems to readily balloon shorter distances, stretches of ocean still act as filters for among-island gene-flow as evidenced by distinct haplotypes on the more isolated islands, high FSTvalues, and strong correlation between intraspecific (but not interspecific) genetic and geographic distances. The new species described here is clearly genetically diagnosable, but morphologically cryptic, at least with reference to the genitalia that typically diagnose spider species. Our results are consistent with the intermediate dispersal model suggesting that good dispersers, such as our study species, limit the effect of oceanic barriers and thus diversification and endemism.
Department of Biology, University of Vermont, Burlington, VT, USA; Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Ingi
I
Agnarsson
Department of Biology, University of Vermont, Burlington, VT, USA.
Stephanie M
SM
LeQuier
Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA; Evolutionary Zoology Laboratory, Biological Institute ZRC SAZU, Ljubljana, Slovenia.
Matjaž
M
Kuntner
Evolutionary Zoology Laboratory, Biological Institute ZRC SAZU, Ljubljana, Slovenia.
Ren-Chung
RC
Cheng
Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Jonathan A
JA
Coddington
Department of Biology, Lewis and Clark College, Portland, OR, USA.
Greta
G
Binford
Biogeography; CarBio; GAARlandia; Intermediate dispersal model; Isolation by distance model; dispersal; diversification