Acanthuridae are the family of surgeonfishes, tangs, and unicornfishes. The family includes about 86 extant species of marine fish living in tropical seas, usually around coral reefs. Many of the species are brightly colored and popular in aquaria.
Salamandridae is a family of salamanders consisting of true salamanders and newts. Salamandrids are distinguished from other salamanders by the lack of rib or costal grooves along the sides of their bodies and by their rough skin. Their skin is very granular because of the number of poison glands. They also lack nasolabial grooves. Most species of Salamandridae have moveable eyelids but lack lacrimal glands.
The Pentastomida are an enigmatic group of parasitic arthropods commonly known as tongue worms due to the resemblance of the species of the genus Linguatula to a vertebrate tongue. They are traditionally seen as crustaceans, even if that position has been questioned.
Algae eater, also called an algivore, is a common name for many bottom-dwelling or algae-eating species that feed on algae. Algae eaters are important for the fishkeeping hobby and many are commonly kept by hobbyists.
The thorny-headed worm family Polymorphidae contains endoparasites which as adults feed mainly in fish and aquatic birds. When this taxon was erected by Meyer in 1931, a subfamily Polymorphinae was established in it. As the Polymorphidae as presently understood would then be monotypic, with no basal genera outside the Polymorphinae, the proposed subfamily is redundant for the time being and therefore most modern treatments simply omit it. Polymorphus minutus is an economically significant parasite in goose and duck farming.
Gigantorhynchus is a genus of Acanthocephala that parasitize marsupials, anteaters, and possibly baboons by attaching themselves to the intestines using their hook-covered proboscis. Their life cycle includes an egg stage found in host feces, a cystacanth (larval) stage in an intermediate host such as termites, and an adult stage where cystacanths mature in the intestines of the host. This genus is characterized by a cylindrical proboscis with a crown of robust hooks at the apex followed by numerous small hooks on the rest of the proboscis, a long body with pseudosegmentation, filiform lemnisci, and ellipsoid testes. The largest known specimen is the female G. ortizi with a length of around 240 millimetres (9.4 in) and a width of 2 millimetres (0.08 in). Genetic analysis on one species of Gigantorhynchus places it with the related genus Mediorhynchus in the family Gigantorhynchidae. Six species in this genus are distributed across Central and South America and possibly Zimbabwe. Infestation by a Gigantorhynchus species may cause partial obstructions of the intestines, severe lesions of the intestinal wall, and may lead to death.
Gonyaulax is a genus of dinoflagellates with the type species Gonyaulax spinifera Diesing. Gonyaulax belongs to red dinoflagellates and commonly causes red tides. It secretes a poisonous toxin known as "saxitoxin" which causes paralysis in humans.
Oligacanthorhynchida is an order containing a single parasitic worm family, Oligacanthorhynchidae, that attach themselves to the intestinal wall of terrestrial vertebrates.
Cavisomidae are a family of parasitic worms from the order Echinorhynchida.
Aspidogaster limacoides is a species of the trematodes in the family Aspidogastridae.
Bucephalidae is a family of trematodes that parasitize fish. They lack suckers, having instead a muscular organ called a "rhynchus" at the front end which they use to attach to their hosts. The characteristics of the rhynchus are used to help define the genera of the family. It is one of the largest digenean families, with 25 genera containing hundreds of described species. Bucephalids are cosmopolitan, having been recorded all over the world. They are parasites of fish from freshwater, marine, and brackish water habitat types.
Proteocephalidae is a diverse family tapeworms with nearly 300 recognized species in 66 genera and 13 subfamilies, whose species are found in every continent. They are mainly parasites of siluriforms and other freshwater fishes, but also parasitize reptiles and amphibians. A typical proteocephalid life cycles include planktonic crustaceans, and small fish as intermediate hosts.
The Capsalidae is a family of monopisthocotylean monogeneans, which includes about 200 species.
Metorchis is a genus of flatworms belonging to the family Opisthorchiidae.
Cercaria is a genus of trematodes belonging to the family Fellodistomidae.
Diplostomidae is a family of trematodes in the order Diplostomida.
Diplectanum is a genus of monopisthocotylean monogeneans in the family Diplectanidae. The genus, created by Karl Moriz Diesing, gave its name to the family Diplectanidae. All its species are parasites of the gill lamellae of teleosts. The type-species of the genus is Diplectanum aequans(Wagener, 1857).
Prosthenorchis is a genus of parasitic worms belonging to the family Oligacanthorhynchidae.
Protostrongylus is a genus of nematodes belonging to the family Protostrongylidae.
Tetrabothrius is a genus of flatworms belonging to the family Tetrabothriidae.
