Testing species boundaries in the Antrodiaetus unicolor complex (Araneae: Mygalomorphae: Antrodiaetidae):

“Paraphyly” and cryptic diversity

Brent E. Hendrixson, Jason E. Bond

Department of Biology, East Carolina University, Howell Science Complex N211, Greenville, NC 27858, USA

Received 29 October 2004; revised 27 January 2005

Available online 4 March 2005

Abstract

The inability to correctly identify species has far reaching implications in nearly all areas of biology, yet few studies investigate methods for delineating species boundaries. Moreover, once these boundaries have been hypothesized, little thought has been given to how these constructs can be further evaluated. We employ a molecular phylogenetic approach using nuclear 28S rRNA and mitochondrial cytochrome c oxidase subunit I genes to test the general eYcacy of species boundaries in the Antrodiaetus unicolor spider species complex. Our analyses provide evidence that An. unicolor is “paraphyletic” with respect to An. microunicolor, indicating that

morphological criteria used to delineate species boundaries undersplits actual species-level diversity in this group of spiders. These analyses also demonstrate that individuals from geographically proximate populations sometimes exhibit considerable molecular divergence, strongly suggesting that An. unicolor is a cryptic species complex. Finally, this molecular approach has provided the phylogenetic framework that is necessary to begin interpreting the vast amount of morphological variation observed in these spiders based upon Wndings from previous studies. Our approach using multiple genes appears to be a rigorous method to critically examine

species boundaries originally based on traditional morphological approaches to spider taxonomy.

 2005 Elsevier Inc. All rights reserved.

Keywords: Antrodiaetus; Congeneric phylogeography; Cryptic species; Paraphyletic species; Species boundaries; Spider taxonomy