chalimus
Chalimus is a larval stage in certain parasitic crustaceans, most commonly copepods such as the sea lice that infest fish. In these species, the chalimus represents an early, sessile juvenile phase during which the parasite remains attached to its host by a frontal filament and does not swim freely.
Following the free-swimming nauplius and copepodid stages, an infective copepodid settles on the host and molts
Chalimus-stage sea lice commonly infest marine fish, including farmed salmon and other commercially important species. They
Chalimus stages are found in several parasitic copepod families, particularly Caligidae (sea lice) and related taxa.