Morphological ontogeny of Hydrozetes paulista (Acari, Oribatida, Hydrozetidae), with comments on Hydrozetes Grandjean.

The morphological ontogeny of Hydrozetes paulista P?rez-??igo & Baggio, 1989 is described and illustrated. This species is monodactylous as adult, with short, setiform bothridial seta and belongs to the ?lacustris species group?. It has 13 pairs of notogastral setae, including c2, but seta c3 is retained by some individuals. Most gastronotal setae of larva are of medium size and barbed, except for longer setae lm, lp and h2, and short and smooth c1 and h3. In the nymphs setae of l-series, h1 and h2 are very long, smooth and dark pigmented, setae h3 and p1 are of medium size, thick, pointed and barbed, and other setae are short and usually smooth; seta lm is located anterior to the gland opening. Hydrozetes paulista is bisexual, but in this study only females were present