Differentiation of body form of Gustavioidea (Acari: Oribatida) in the light of ontogeny of three species

Differentiation of body form of Gustavioidea in the light of ontogeny of Dorycranosus curtipilis (Liacaridae), Ceratoppia sphaerica and Ceratoppiaquadridentata (Peloppiidae) was investigated, and morphology of juveniles of these species was described and illustrated for the first time. The juveniles of D. curtipilis differ distinctly from those of Ceratoppia species mainly by stronger chelicerae, more elongated body, and convex gastronotum, oval cross section, small and clavate sensillus, and rather thin, and pliable setae. The protonymphs of all these species lose gastronotal setae of d-series, and these setae are absent in subsequent nymphs and adult. The adult loses further notogastral setae, such that 11 pairs remain in D. curtipilis, but only two pairs in Ceratoppia species. Diagnoses of these species are enriched with morphological characters of juveniles, and the morphology of Ceratoppiabipilis is briefly compared, as are aspects of Gustaviafusifer (Gustaviidae).