Variation in cuticular scales of the lynx spiders of the genus Hamataliwa and other genera (Araneae, Oxyopidae)

This study presents the first complete description of the external and inte rnal morphology of cuticular scales of spiders of the genus Hamataliwa and is also the first examination of intrageneric variation in the morphology o f the scales of the lynx spiders (Oxyopidae). The cuticular scales of nine species, including taxa from Australia and Central and North America, were examined using scanning electron microscopy, paraffin carving, and transmis sion electron microscopy (whole mounts only). The surface morphology and in ternal anatomy of the scales exhibit considerable intra- and inter-specific variation. The structures that exhibit the most variation are (i) the plic ae, small lateral ridges on the dorsal surface, which show variation in bot h morphology and pattern, and (ii) the rod-shaped, branched cuticular eleme nts that occur within the lumina, which vary most dramatically in pattern. Scale morphology also varies regionally (i.e., with respect to location on the body) in most species. A comparison of the morphology of scales of Hama taliwa spp. with those of the striped lynx spider, Oxyopes salticus, and th e green lynx spider, Peucetia viridans, suggests that scales may represent a useful phylogenetic character for understanding relationships both within and between genera in the Oxyopidae.