Palaeacanthocephala
Encyclopedia
Palaeacanthocephala is a class
within the phylum
Acanthocephala
. The adults of these parasitic platyzoa
ns feed mainly on fish
, aquatic bird
s and mammal
s.
The nuclei of the hypodermis
(outer layer of skin) are fragmented and the males have two to seven cement glands, unlike their relatives the Archiacanthocephala
which always have eight.
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
within the phylum
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
Acanthocephala
Acanthocephala
Acanthocephala is a phylum of parasitic worms known as acanthocephales, thorny-headed worms, or spiny-headed worms, characterized by the presence of an evertable proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host...
. The adults of these parasitic platyzoa
Platyzoa
The Platyzoa are a group of protostome animals proposed by Thomas Cavalier-Smith in 1998. Cavalier-Smith included in Platyzoa the Phylum Platyhelminthes or flatworms, and a new phylum, Acanthognatha, into which he gathered several previously described phyla of microscopic animals...
ns feed mainly on fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, aquatic bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s and mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s.
The nuclei of the hypodermis
Hypodermis
The hypodermis, also called the hypoderm, subcutaneous tissue, or superficial fascia is the lowermost layer of the integumentary system in vertebrates. Types of cells that are found in the hypodermis are fibroblasts, adipose cells, and macrophages...
(outer layer of skin) are fragmented and the males have two to seven cement glands, unlike their relatives the Archiacanthocephala
Archiacanthocephala
Archiacanthocephala is a class within the phylum of Acanthocephala . They are microscopic parasitic worms that attach themselves to the intestinal wall of terrestrial vertebrates, including man...
which always have eight.