The Polydesmidan millipede species Orthomorpha coarctata, also known as the long-flange millipede, belongs to the family Paradoxosomatidae. Although it is thought to have originated in Southeast Asia, it has spread to other tropical and subtropical regions of the world due to human activity, including the West Indies, the Gulf Coast of North America, the Galápagos Islands and the Hawaiian Islands.
Description
- Males are slightly smaller, measuring between 14.5-20.5 mm long and 1.5 to 2.7 mm wide, while females are slightly larger, measuring between 16.5-27.5 mm long and 1.6 to 3.2 mm wide.
- By possessing proportionately longer and pointier paranota (lateral keels) on mid-body segments and longer gonopods, O. coarctata can be recognized from Oxidus gracilis, another widely introduced Asian millipede (male reproductive appendages).
- The gonopods of O. coarctata are distinctive within the genus Orthomorpha because they have a single, straightforward tip, whereas those of other species have two or three lobes.
- Some writers have classified O. coarctata as a unique, monotypic genus called Asiomorpha as a result of this distinction.
