acanthor

a·can·thor

(ă-kan'thōr),
The spindle-shaped embryo, with rostellar hooks and body spines, formed within the egg shell of Acanthocephala; this stage burrows into the body cavity of its first intermediate host, usually a crustacean in aquatic cycles, or insects in terrestrial cycles.
[G. akantha, thorn or spine]

acanthor

larva contained within the mature eggs of Acanthocephalans: the egg is thick-shelled and the larva carries an anterior circlet of hooks and spines.