Interspecific, ontogenetic, and sexual variation in ozopore morphology among cosmetid harvestmen (Arachnida, Opiliones, Laniatores)
| Autor: | Saoirse Teevan‐Kamhawi, Devin Calpo, Victor R. Townsend |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine Male Scent gland Tarsus (eyelids) Zoology Opiliones 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Ozopore Arachnida medicine Animals Carapace Scent Glands Nymph Phylogeny biology biology.organism_classification 030104 developmental biology medicine.anatomical_structure Biological Variation Population Cosmetidae Microscopy Electron Scanning Animal Science and Zoology Female Laniatores Developmental Biology |
| Zdroj: | Journal of morphologyREFERENCES. 280(10) |
| ISSN: | 1097-4687 |
| Popis: | The ozopores of cosmetid harvestmen rest upon lateral projections of the carapace, have simple or highly reduced channels, and are partially obscured by enlarged dorsal processes associated with coxae I and II. Rather than use scent gland secretions to form a chemical shield on the dorsum, the cosmetid harvestman exhibits a unique defensive behavior known as "leg dabbing" in which the distal tip of tarsus I or II is dipped into fluid that accumulate at the base of coxa II and the droplet on the tarsus is pointed toward the predator. Relatively little is known about interspecific variation in ozopore morphology among cosmetid harvestmen. In this study, we used scanning electron microscopy to examine the ozopores of males and females of nine species as well as those of antepenultimate nymphs for two species. Among adults, we found differences between species in the shapes of the ozopores (round or subtriangular), the morphology of the dorsal and lateral channels (if present), and the relative size, shape and armature of the dorsal posterior process (dpp) of coxa I and the dorsal anterior process (dap) of coxa II. Our observations suggest that the morphology of dpp I and dap II could be sources for systematic characters in future phylogenetic studies of the Cosmetidae. We observed ontogenetic differences but relatively little intersexual variation in the morphology of the ozopore. The ozopores of nymphs are generally more oval than those of adults and the opening of the ozopore of the nymph is less obstructed, if at all, by the dorsal coxal processes of legs I-II. These morphological differences suggest that nymphs may use scent gland secretions in a manner different from that of adults. |
| Databáze: | OpenAIRE |
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