Enoplea (enopleans) is a class, which with the classes Secernentea and Chromadorea make up the phylum Nematoda in current taxonomy. The Enoplea are considered to be a more ancestral group than the Chromadorea, and researchers have referred to its members as the "ancestrally diverged nematodes", compared to the "more recently diverged nematodes" of Chromadorea.
Subclass Rhabditia is mostly composed of parasitic nematodes, though there are some free-living species as well. Phasmids are well-developed, while amphids are poorly developed or absent in this group.
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 assign 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. These "worms" contain a number of important parasites of humans and domestic animals.
Secernentea was a class of nematodes in the Classical Phylogeny System and is no longer in use. This morphological-based classification system has been replaced by the Modern Phylogeny system, where taxonomy assignment is based on small subunit ribosomal DNA.
The Chromadorea are a class of the roundworm phylum, Nematoda. They contain a single subclass (Chromadoria) and several orders. With such a redundant arrangement, the Chromadoria are liable to be divided if the orders are found to form several clades, or abandoned if they are found to constitute a single radiation.
Empididae is a family of flies with over 3,000 described species occurring worldwide in all the biogeographic realms but the majority are found in the Holarctic. They are mainly predatory flies like most of their relatives in the Empidoidea, and exhibit a wide range of forms but are generally small to medium-sized, non-metallic and rather bristly.
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.
Diplogasterida was an order of nematodes. It was sometimes placed in a monotypic subclass Diplogasteria, but molecular phylogenetic evidence has shown it to be embedded in the family Rhabditidae. The confusion of having a hierarchical nesting of groups that were formerly mutually exclusive has led to a profusion of names. Although completely revised taxonomy of nematodes that builds on recent classification systems as well as recent phylogenetic evidence is still necessary, most contemporary taxonomic studies now treat all groups listed under "Diplogasterina" below as a single family, Diplogastridae.
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs.
The nematodes, roundworms or eelworms constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. Most species are free-living, feeding on microorganisms, but there are many that are parasitic. The parasitic worms (helminths) are the cause of soil-transmitted helminthiases.
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. The Oxyurida and Rhigonematida are occasionally placed in the Ascaridina 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.
Habronematoidea is a superfamily of spirurian nematodes in the large order Spirurida. Like all nematodes, they have neither a circulatory nor a respiratory system.
Thelazioidea is a superfamily of spirurian nematodes in the large order Spirurida. Like all nematodes, they have neither a circulatory nor a respiratory system.
The Onchocercidae are a family of nematodes in the superfamily Filarioidea. This family includes some of the most devastating human parasitic diseases, such as lymphatic filariasis, onchocerciasis, loiasis, and other filariases.
Dirofilaria is a filarial (arthropod-borne) nematode (roundworm), in the family Onchocercidae. Some species cause dirofilariasis, a state of parasitic infection, in humans and other animals.
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens.
Capillariidae is a family of parasitic nematodes. All its members are parasites in vertebrates when they are in their adult stage.
Setaria is a genus of parasitic roundworms that infect domesticated mammals such as pigs, camels, cattle and horses. Some species also infect wild mammals such as deer and antelope. The genus consists of about 43 species. Members of the genus are uniquely parasites in the abdominal cavity of the body. They are mostly large-sized roundworms, possessing an elaborate head (cephalic) region that is characterised by spines, presence of four lips, and well-guarded mouth. Little is known about their pathogenic effects, but some are known to affect nervous system and eye. The larval infective forms are transmitted from one animal to another by the bite of mosquitoes and flies. In addition Setaria marshalli can be transmitted from the womb to new-born calf.
Ascarophis is a genus of parasitic nematodes, belonging to the family Cystidicolidae. Species of Ascarophis are parasitic as adults in the gastrointestinal tract of marine and estuarine fishes.
