Reproductive morphology of three species of neotropical harvestmen (Opiliones, Laniatores, Gonyleptoidea).

Illustrations of penis morphology are essential components of species descriptions for harvestmen belonging to the suborder Laniatores. Male genitalia are important sources of taxonomic characters and are generally assumed to exhibit relatively little intraspecific variation. In contrast, descriptions of female reproductive morphology are rarely included in taxonomic descriptions of laniatorean harvestmen. As a result, relatively little is known about variation in the external features of the ovipositor. In this study, we used scanning electron microscopy to examine variation in male and female reproductive morphology among three species of harvestmen that are members of the superfamily Gonyleptoidea. Specifically, we examined the microanatomy of penises and ovipositors of Cynortula granulata (Cosmetidae), Phareicranaus calcariferus (Cranaidae), and Rhopalocranaus albilineatus (Manaosbiidae). Our results support the general observation that male reproductive morphology is conservative and displays little intraspecific variation. We observed considerable intraspecific variation in the number and shape of marginal setae on the ventral plate of the penis, but little or no variation in the morphology of the distal border of the ventral plate or the shape of the glans penis or stylus. With respect to female genitalia, we observed considerable intraspecific variation in the number of peripheral setae on the distal tip of the ovipositor. We also observed interspecific variation in the morphology of the peripheral setae (surface of the shaft and at shape of the distal tip), the distribution and morphology of smaller setae on the external surface of the ovipositor, and the surface texture of the external lobes. Our results indicate that there are several features associated with ovipositor morphology among laniatorean harvestmen that may represent potentially informative taxonomic characters.