Crustacean larva stop after a single copepodid stage. Once the gonads develop, there are no further moults. Chalimus (plural chalimi) is a stage of development of a copepod parasite of fish, such as the salmon louse ("Lepeophtheirus salmonis"). "Chalimus" Burmeister, 1834 is also a synonym for "Lepeophtheirus" Nordmann, 1832. The single genus in the Facetotecta, "Hansenocaris", is only known from its larvae. They were first described by Christian Andreas Victor Hensen in 1887, and named "y-nauplia" by Hans Jacob Hansen, assuming them to be the larvae of barnacles. The adults are presumed to be parasites of other animals. Crustacean larva Crustaceans may
Crustacean larva and hatch with a full complement of adult appendages with the exceptions of the uropods and the first pair of pleopods. The larvae of the Achelata (slipper lobsters and spiny lobsters) are unlike any other crustacean larvae. The larvae are known as "phyllosoma", after the genus "Phyllosoma" erected by William Elford Leach in 1817. They are flattened and transparent, with long legs and eyes on long eyestalks. After passing through 8–10 phyllosoma stages, the larva undergoes "the most profound transformation at a single moult in the Decapoda", when it develops into the so-called "puerulus" stage, which is an immature form