An "aquatic" millipede from a Central Amazonian inundation forest.

Advanced juvenile stages and subadults ofGonographis adisi (Pyrgodesmidae, Diplopoda) pass annual flooding periods of 5-6 months under loose bark of submerged tree trunks in a black-water inundation forest near Manaus. Animals graze on algae and show cutaneous respiration, with an uptake of dissolved oxygen greater than 10 μl/mg dry weight/h. Some subadults become adults during the following non-inundation period and reproduce. Most of their progeny reach the subadult stage before the next inundation period and undergo flooding along with the remaining subadults from the preceding generation. Maximum flood tolerance of immatures in the laboratory was 11 months. Adults do not withstand inundation.