Nauplii released from adult females swim in water for several days without taking any food (the larva has no mouth and no intestine) and transform into cypris larvae (cyprids) after several moults. Like the nauplii, the cyprids are lecithotrophic (non-feeding). The female cypris in Kentrogonida settles on a host and metamorphoses into a specialized juvenile form called a kentrogon, which carries no visible segmentation and does not have any other appendages than the antennules that are used to attach itself to the host, and whose only purpose is to inject a cell mass named the vermigon into the host's hemolymph through a retractive hollow stylet on their head. The kentrogon stage seems to have been lost in all of the Akentrogonida, where the cypris injects the vermigon through one of their antennules instead. The vermigon grows into root-like threads through the host's tissue, centering on the digestive system and especially the hepatopancreas, and absorb nutrients from the hemolymph. This network of threads is called the interna. The female then grows a sac-like externa, which consists of a mantle, a mantle cavity, an ovary and a pair of passageways known as cell receptacles, extruding from the abdomen of the host.