The life cycle of Limnozetes ciliatus (Schrank, 1803) (Acari: Oribatida)

Abstract

Some aspects of the life cycle of Limnozetes ciliatus, the dominant oribatid species in a Sphagnum mire at Yachidaira, Northeast Japan, were surveyed using laboratory cultures and field surveys. Reproductive characteristics, ontogenetic development and release of faecal pellets by the adults were investigated. This species is oviparous and laid a maximum of 11 eggs (mean 3.4) one by one at 25°C in a life cycle. Fewer eggs were laid at 15°C and 20°C. During ontogenetic development, the number of pair of notogastral setae and genital setae changed as follows: 12-15-15-15-10 (pairs) and 0-2-4-6-7 (pairs), respectively. The adult deposited many faecal pellets under pieces of decayed tissues of Moliniopsis japonica; the largest at 25°C with a maximum of 1,528 faecal pellets (0.195 mm³ in volume) per animal within a lifetime of 150 days. Fewer faecal pellets were released at 15°C and 20°C. The results suggest that this species is an important decomposer in this habitat where there are few macrodecomposers, and shows a clear difference in metabolic rate between 20°C and 25°C.