acanthor

The term "acanthor" refers to the larval stage of a spiny-headed worm, which belongs to the invertebrate phylum Acanthocephala. These parasites have a proboscis, or snout, equipped with hooks, which gives them their name.

The life cycle of a spiny-headed worm involves two hosts: an arthropod (like an insect or crustacean) as the intermediate host and a vertebrate (often fish) as the definitive host. After the fertilized eggs are excreted by the vertebrate host, they are ingested by an arthropod. Inside the arthropod, the larva, known as an acanthor, penetrates the gut wall and develops into a new stage called an acanthella, which is a miniature version of the adult worm. This then becomes a cystacanth. When the cystacanth is eaten by a vertebrate, it matures into an adult spiny-headed worm within the vertebrate's intestine.1