Ascaridida
Encyclopedia
The order
Ascaridida includes several families of parasitic roundworms with three "lips" on the anterior end. They were formerly placed in the subclass
Rhabditia
by some, but morphological and DNA sequence
data rather unequivocally assigns them to the Spiruria
. The Oxyurida
and Rhigonematida are occasionally placed in the Ascaridida as superfamily
Oxyuroidea, but while they seem indeed to be Spiruria, they are not as close to Ascaris
as such a treatment would place them.
In an alternate taxonomic treatment, the Ascaridida are ranked as an infraorder Ascaridomorpha.
The suborder Dioctophymatina is doubtfully valid; it contains a mere 2 families
, one of which is monotypic
. Most Ascaridida are placed in the suborder Ascaridina
. These "worm
s" contain a number of important parasites of humans and domestic animals.
Important families
include:
These all belong in the superfamily
Ascaridoidea.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Ascaridida includes several families of parasitic roundworms with three "lips" on the anterior end. They were formerly placed in the subclass
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...
Rhabditia
Rhabditia
Subclass Rhabditia is mostly composed of parasitic nematodes , though there are some free-living species as well...
by some, but morphological and DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data rather unequivocally assigns them to the Spiruria
Spiruria
Subclass Spiruria comprises mostly parasitic secernentean nematodes. In an alternate classification, they are treated as suborder Spirurina, with the orders listed here being ranked as infraorders....
. The Oxyurida
Oxyurida
Oxyurida is an order of nematode worms of the class Secernentea. It consists of four families, one of which contains the human pinworm ....
and Rhigonematida are occasionally placed in the Ascaridida as superfamily
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
Oxyuroidea, but while they seem indeed to be Spiruria, they are not as close to Ascaris
Ascaris
Ascaris is a genus of parasitic nematode worms known as the "giant intestinal roundworms". One species, A. suum, typically infects pigs, while another, A. lumbricoides, affects human populations, typically in sub-tropical and tropical areas with poor sanitation. A...
as such a treatment would place them.
In an alternate taxonomic treatment, the Ascaridida are ranked as an infraorder Ascaridomorpha.
The suborder Dioctophymatina is doubtfully valid; it contains a mere 2 families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, one of which is monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
. Most Ascaridida are placed in the suborder Ascaridina
Ascaridina
The suborder Ascaridina contains the bulk of the Ascaridida, parasitic roundworms with three "lips" on the anterior end. The Ascaridida were formerly placed in the subclass Rhabditia by some, but morphological and DNA sequence data rather unequivocally assigns them to the Spiruria...
. These "worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
s" contain a number of important parasites of humans and domestic animals.
Important families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
include:
- AnisakidaeAnisakidaeAnisakidae is a family of intestinal roundworms. They are also called the marine ascarids. The larvae of these worms can cause anisakiasis when ingested by humans, but do not reproduce except in marine mammals or seabirds.- Selected genera :...
, also called the "marine mammalMarine mammalMarine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
ascarids". The larvae of these worms cause anisakiasis when ingested by humans, but do not reproduce. - AscarididaeAscarididaeAscarididae is a family of the large intestinal roundworms. Members of the family are intestinal parasites infect all classes of vertebrates."...
, which includes the giant intestinal roundworms (Ascaris spp.). - CosmocercoidesCosmocercoidesCosmocercoides is a genus of nematode within the order Ascaridida. Nematodes within the genus Cosmocercoides have been found as parasites within the rough-skinned newt, Taricha granulosa...
, which includes taxa that parasitize certain amphibianAmphibianAmphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s - ToxocaridaeToxocaridaeToxocaridae is a zoonotic family of parasitic nematodes that infect canids and felids and which cause toxocariasis in humans...
, which includes parasites of canids, felids, and raccoonRaccoonProcyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...
s, but which can unsuccessfully parasitize humans and cause visceral larva migrans.
These all belong in the superfamily
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
Ascaridoidea.