''Zoosphaerium neptunus'', also known as the giant emerald pill millipede, is a species of millipede within the family Arthrosphaeridae. It is the largest known

pill-millipede Pill millipedes are any members of two living (and one extinct) orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), al ...

in the world, with some individuals reaching lengths of 90 mm (3.5 inches) long. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

, where it is known to swarm at certain times of the year.

Description

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

is present within the species, with females reaching larger sizes than males. Males can reach up to 45 mm (1.8 inches) long, while females reach 90 mm (3.5 inches) long.

Distribution and habitat

''Zoosphaerium neptunus'' can be found living in moist lowland rainforest habitats up to elevations of 850 metres above sea level. The species is endemic to Madagascar and is widely distributed in Eastern Madagascar, however populations have also been recorded in Northern and Southern Madagascar.

References

Sphaerotheriida Endemic fauna of Madagascar Arthropods of Madagascar Millipedes of Africa Animals described in 1872 {{myriapoda-stub