Acanthocephala
 |
Polymorphus sp. showing the spiny proboscis
that gives acanthocephalans their name. Image source: University of
Edinburgh
|
Spiny-headed worms, a phylum of worms parasitic
(see parasite) on vertebrates such as fish
and birds. Named for the retractable proboscis, which bears tiny hooks that
anchor them to the intestinal walls of their hosts, these worms are so degenerate
that most have little more than a reproductive system and a simple brain.
They often cause fatal infection. Acanthocephalans require two hosts to
complete the life cycle. The young are parasitic in arthropods
and the adults, which are typically 1–2 cm (0.4–0.8 in) long
and have an elongated, cylindrical body, are parasitic in vertebrates (especially
fish), living in the digestive tract. As in the case of tapeworms, acanthocephalans
have no gut and absorb nutrients directly from the host's gut through the
tegument. About 1150 species are known.
Related category
• ZOOLOGY
Also on this site:
Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|
