Archispirostreptus gigas

Archispirostreptus gigas, known as the giant African millipede, shongololo or Bongololo, is the largest extant species of millipede, growing up to 33.5 centimetres (13.2 in) in length, 67 millimetres (2.6 in) in circumference. It has approximately 256 legs, although the number of legs changes with each molting so it can vary according to each individual.^[2]

Giant African millipede
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Myriapoda
Class:	Diplopoda
Order:	Spirostreptida
Family:	Spirostreptidae
Genus:	Archispirostreptus
Species:	A. gigas
Binomial name
Archispirostreptus gigas (Peters, 1855)
Synonyms[1]
Spirostreptus gigas Peters, 1855 Aethiopistreptus attemsi Verhoeff, 1938 Spirostreptus plumaceus Voges, 1878 Spirostreptus semicylindricus Voges, 1878 Spirostreptus opistheurys Attems, 1902 Spirostreptus msalaensis Kraus, 1958

It is a widespread species in lowland parts of East Africa, from Mozambique to Kenya, but rarely reaches altitudes above 1,000 metres (3,300 ft).^[3] It lives mostly in forests, but can also be found in areas of coastal habitat that contain at least a few trees.^[3] It is native to Southern Arabia, especially Dhofar.

In general, giant millipedes have a life expectancy of about 7–10 years.^[4]

Defence

Giant millipede coiled in defence

Giant millipedes have two main modes of defence if they feel threatened: curling into a tight spiral exposing only the hard exoskeleton, and secretion of an irritating liquid from pores on their body. This liquid can be harmful if introduced into the eyes or mouth.^[4] Because of this defense, A. gigas is one of the few invertebrates that driver ants are incapable of taking as prey. The chemicals identified in this millipede’s defensive secretion are toluquinone and 2-methoxy-3-methylbenzoquinone.^[5]

Small mites are often observed crawling on their exoskeleton and among their legs. The millipedes have a symbiotic relationship with these mites, in which the mites help clean the millipede's exoskeleton in exchange for food and the protection of their host.^[6]

A docile species, A. gigas is sometimes seen in the pet trade.^[7] However, the U.S. federal government requires anyone bringing giant millipedes into the country to have permits for them.^[8]

Ecological role

Archispirostreptus gigas plays an important role as a decomposer in tropical ecosystems. They help break down decaying plant material which returns nutrients to the soil and supports forest floor health. A. gigas uses hemocyanin, a copper-based protein, for oxygen transport. They are also well adapted to low-oxygen environments like rotting logs and dense leaf litter, which allows them to stay active in areas where oxygen is limited. Thus, they thrive in key nutrient-cycling zones of the ecosystem.^[9]

Giant African millipede in Namibia