chalimus

(Subclass Copepoda):

One of up to four stages in copepodid phase of development of caligid-like parasitic copepods; the chalimus usually is attached to the host, often by a frontal filament held by maxilla 2. The first chalimus is molted from the first copepodid stage; the four chalimus stages correspond to the second to fifth copepodid stages [Ferrari and Dahms, in press].

(Subclass Copepoda):

The post-copepodid developmental stage of most siphonostomatoid fish parasites, characterised by possession of a frontal filament for attachment to the host [Boxshall and Halsey, 2004].