Family: Zetomimidae
Taxonomy: This is the only species in this genus found at La Selva, and is described in Behan-Pelletier (1998). Adults, though similar in shape to Heterozetes heleios found in the same habitat, are smaller, being about 0.3mm in length. This species shows sexual dimorphism rare elsewhere in Oribatida, but similar to that in H. heleios. Almost the entire ventral and anal plates of the male are porose. In contrast, female ventral and anal plates are without porose regions othere than the postanal porose area. This distinct sexual dimorphism, discussed in Norton and Alberti (1997), possibly plays a role in intraspecific communication, with the male producing semiochemicals (sex-attractants or general aggregation pheremones) that are involved in reproductive biology.
Habitat: This is among the few oribatid species found in the water in the experimental swamp at La Selva. Adults are easily collected by extracting handfuls of wet vegetation from on and in the water in the swamp in Berlese funnels. This species has never been collected in the swamp during dry periods when there is no available free-standing water. All known species in the genus are associated with aquatic habitats.
Ecology: Members of this species probably graze algae and fungi on the leaves of aquatic plants.
Reference:
Behan-Pelletier VM 1998. Ceratozetoidea (Acari: Oribatida) of lowland tropical rainforest, La Selva, Costa Rica. Acarologia 39: 349-381.
Norton RA and Alberti G 1997. Porose integumental organs of oribatid mites (Acari, Oribatida). 3. Evolutionary and ecological aspects. Zoologica. 146:115-143.