Sciaenidae is a family of ray-finned fishes belonging to the order Acanthuriformes. They are commonly called drums or croakers in reference to the repetitive throbbing or drumming sounds they make. The family consists of about 293 to 298 species in about 66 or 67 genera.
Myxozoa is a subphylum of aquatic cnidarian animals – all obligate parasites. It contains the smallest animals ever known to have lived. Over 2,180 species have been described and some estimates have suggested at least 30,000 undiscovered species. Many have a two-host lifecycle, involving a fish and an annelid worm or a bryozoan. The average size of a myxosporean spore usually ranges from 10 μm to 20 μm, whereas that of a malacosporean spore can be up to 2 mm. Myxozoans can live in both freshwater and marine habitats.
Trematoda is a class of flatworms known as flukes or trematodes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish.
Monogeneans, members of the class Monogenea, are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reproductive structures.
Myxobolus cerebralis is a myxosporean parasite of salmonids that causes whirling disease in farmed salmon and trout and also in wild fish populations. It was first described in rainbow trout in Germany in 1893, but its range has spread and it has appeared in most of Europe, the United States, South Africa, Canada and other countries from shipments of cultured and wild fish. In the 1980s, M. cerebralis was found to require a tubificid oligochaete to complete its life cycle. The parasite infects its hosts with its cells after piercing them with polar filaments ejected from nematocyst-like capsules. This infects the cartilage and possibly the nervous tissue of salmonids, causing a potentially lethal infection in which the host develops a black tail, spinal deformities, and possibly more deformities in the anterior part of the fish.
Myxobolus is a genus of myxozoa that includes important parasites of fish like Myxobolus cerebralis. The genus is polyphyletic, with members scattered throughout the myxozoa. Some stages of Myxobolus species were previously thought to be different organisms entirely, but are now united in this group. Some fish species, such as the thicklip grey mullet, can harbour a dozen of Myxobolus species.
Ceratonova shasta is a myxosporean parasite that infects salmonid fish on the Pacific coast of North America. It was first observed at the Crystal Lake Hatchery, Shasta County, California, and has now been reported from Idaho, Oregon, Washington, British Columbia and Alaska.
Myxobolidae is a family of myxosporean parasites which typically infect freshwater fishes, and includes the economically significant species, Myxobolus cerebralis. They have been shown to have a complex life cycle, involving an alternate stage in an invertebrate, typically an annelid or polychaete worm.
Tetracapsuloides bryosalmonae is a myxozoan parasite of salmonid fish. It is the only species currently recognized in the monotypic genus Tetracapsuloides. It is the cause of proliferative kidney disease (PKD), one of the most serious parasitic diseases of salmonid populations in Europe and North America that can result in losses of up to 90% in infected populations.
Piaractus mesopotamicus, the small-scaled pacu, Paraná River pacu or simply pacu, is a South American ray-finned fish that is native to the Paraguay-Paraná River basin, but it has been introduced by aquaculture activities in a wider area. In its native range it is also known as the pacú chato, pez chato or mbiraí-piraí.
Galactosomum is a genus of flukes in the family Heterophyidae. There are currently 28 recognised species within the genus. They mainly infect aquatic birds, but often infest fish as larvae. Three species are known to use marine mammals as hosts.
Pacu is a common name used to refer to several species of omnivorous South American freshwater serrasalmid fish related to piranhas. Pacu and piranha do not have similar teeth, the main difference being jaw alignment; piranha have pointed, razor-sharp teeth in a pronounced underbite, whereas pacu have squarer, straighter teeth and a less severe underbite, or a slight overbite. Pacu, unlike piranha, mainly feed on plant material and not flesh or scales. Additionally, the pacu can reach much larger sizes than piranha, at up to 1.08 m in total length and 40 kg (88 lb) in weight.
Piaractus brachypomus, the pirapitinga, is a large species of pacu, a close relative of piranhas and silver dollars, in the serrasalmid family. It is native to the Amazon basin in tropical South America, but it formerly included populations in the Orinoco, which was described in 2019 as a separate species, P. orinoquensis. Additionally, P. brachypomus is widely farmed and has been introduced to other regions. In South Florida they are invasive in rivers, canals or lakes.
Myxobolus cordeiroi is a myxozoan parasite of freshwater fish.
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.
Piaractus is a genus of large serrasalmid from South America. The two traditionally recognized species of Piaractus are very similar in appearance and were formerly included in the genus Colossoma, which currently only contains another similar species, the tambaqui. A third Piaractus was described in 2019 as a new species, but it was formerly considered a subpopulation of P. brachypomus.
Percopsis omiscomaycus, also known as the trout-perch, the grounder or the sand minnow, is one of two species in the family Percopsidae. Its name comes from the Greek root words perc, meaning perch and opsi meaning appearance. The species name omiscomaycus is thought to be derived from a Native American word meaning trout. These are freshwater fish that prefer clear to slightly turbid water, and are found in rivers and lakes throughout North America. They are a generally small fish found in deep waters by day, but which migrate to shallower waters at night.They are most often seen washed up on beaches and are rarely seen alive or correctly identified. The trout-perch possess characteristics similar to both the trout and the perch. They are an important source of food for many predator fish such as walleye, northern pike, and lake trout. They are not a major human fishery, but are occasionally used as a bait fish.
The ginbuna, sometimes referred to as silver crucian carp or Japanese silver crucian carp, is a species of freshwater fish in the carp family. It is native to lakes and rivers in Japan.
Kritskyia is a genus of monogeneans in the family Ancyrocephalidae.
Ellipsomyxa is a genus of cnidarian that is part of the family Ceratomyxidae.
