Phylogenetic significance of the morphology of the cuticular scales of the lynx spiders (Araneae: Oxyopidae)

Abstract

In spiders, cuticular scales are flattened, hollow setae that occur in a variety of shapes and colours. Using transmission electron microscopy and scanning electron microscopy, we examine and provide descriptions of the external and internal anatomy of prosomal and opisthosomal scales of 70 species of lynx spiders (Araneae, Oxyopidae), representing the genera Hamataliwa, Hostus, Oxyopes, Peucetia, Schaenicoscelis, Tapinillus, and Tapponia. The cuticular scales of these taxa exhibit regional (with respect to location on the body), sexual, inter- and intrageneric variation in external and internal morphology. In the genera, Peucetia, Schaenicoscelis, and Tapinillus, cuticular scales are plumose and only occur on the prosoma. Species of the genera Hamataliwa and Tapponia, have lanceolate scales that occur on the prosoma, legs, and opisthosoma. Hostus has spatulate scales in these areas. In the genus Oxyopes, most species have lanceolate scales on the prosoma and spatulate scales on the legs and opisthosoma. Examinations of the genitalia of 82 species of lynx spiders, revealed a strong correlation between genitalic morphology and scale shape and distribution.