acanthocephalans

Acanthocephalans have complex life cycles, involving a number of hosts, for both developmental and resting stages.

Acanthocephalans have no gut and absorb nutrients directly from the host's gut.

In acanthocephalans, adult males have cement glands in their posterior ends.

Acanthocephalans lack a mouth or alimentary canal.

There are several morphological characteristics that distinguish acanthocephalans from other phyla of parasitic worms.

The acanthocephalans lack an excretory system, although some species have been shown to possess flame cells (protonephridia).

However, most other acanthocephalans have infective larvae that more closely resemble underdeveloped adult worms.

Acanthocephalans do not have digestive tracts and absorb nutrients through the tegument, the external layer.

Acanthocephalans have complex life cycles, with various hosts, including invertebrates, fishes, amphibians, birds, and mammals.

In some recent treatments, rotifers are placed with acanthocephalans in a larger clade called Syndermata.

"Acanthognatha" is a similar grouping, including rotifers, acanthocephalans, gastrotrichs, and gnathostomulids.

Telosentis is a genus of acanthocephalans.

Acanthocephalans are highly adapted to a parasitic mode of life, and have lost many organs and structures through evolutionary processes.

The acanthocephalans Acanthocephaloides propinquus are mos numerous.

Cobia are frequently parasitized by nematodes, trematodes, cestodes, copepods and acanthocephalans.

They host numerous endoparasites, such as nematodes, cestodes, trematodes, the sporozoan Isopora, and acanthocephalans.

While acanthocephalans rarely infect humans, there have been several cases reported of M. moniliformis causing acanthocephaliasis in humans as their definitive hosts.

Parasites found in mice from Florida were six species of nematodes, one each of trematodes and acanthocephalans, and two of fleas.

Acanthocephalans are sexually dimoprhic- adult males are generally 4 to 5 cm long while females are longer, ranging from lengths of 10 to 30 cm.

Parasites of Atlantic cod include copepods, digeneans, monogeneans, acanthocephalans, cestodes, nematodes, myxozoans and protozoans:

The nematodes and the related nematomorphs may be relatively primitive, but the present proximity of groups such as the rotifers and the related acanthocephalans could require revision.

They are also susceptible to parasites, both external ones like barnacles and remoras, and internal ones, like nematodes, trematodes, cestodes and acanthocephalans.

Some of the acanthocephalans (perforating acanthocephalans) can insert their proboscis in the intestine of the host and open the way to the abdominal cavity.

This species is often parasitized by minute worms under the skin, identified as "entozoa" (an obsolete grouping that included acanthocephalans, trematodes, cestodes, and nematodes) and named Cysteocercus temerae by Cantor (1850).

Like many other acanthocephalans, recent studies have shown that the presence of cystacanth of Profilicollis antarcticus causes behavioral alterations due to changes in the levels of hemolymph dopamine in its intermediate host, the crab Hemigrapsus crenulatus.