Microphallus is a genus of parasitic trematodes (flukes) in the family Microphallidae. The Greek name means "tiny penis".
Microphallus is a genus of parasitic trematodes (flukes) in the family Microphallidae. The Greek name means "tiny penis".
They are parasitic on a variety of molluscs, crustaceans, birds, and mammals, some species having complex life cycles involving more than one host.
For example, Microphallus piriformes parasitizes the rough periwinkle ( Littorina saxatilis ); when these are eaten by herring gulls it infects the bird and lays its eggs in the bird's feces to infect new periwinkles.
Other intermediate hosts include, for example New Zealand mud snail Potamopyrgus antipodarum [2] [3] and others.
Several species are notable for manipulating or influencing their hosts. Microphallus piriformes causes its host, the rough periwinkle, to move upwards, making it more vulnerable to predation by herring gulls. Microphallus pseudopygmaeus chemically castrates (parasitic castration) its host, the snail Onoba aculeus , and causes it to grow larger than normal (it is not clear if this gigantism benefits the host or parasite or if it is a non-adaptive side-effect). [4] Microphallus papillorobustus causes its host, the lagoon sand shrimp ( Gammarus insensibilis ) to swim upwards, making it more vulnerable to predation. [5] Some species of this genus "hitch-hike" on the manipulations of other species; for example, Microphallus hoffmanni parasitizes the same sand shrimps as Microphallus papillorobustus but does not manipulate the shrimps itself, instead benefiting from the latter's manipulation of the host.
An undescribed Microphallus species is a widespread and locally common parasite in New Zealand lakes and streams. Multilocus allozyme genotype data show that this Microphallus is a single outbred species with high levels of gene flow among South Island populations. The parasite exclusively uses Potamopyrgus antipodarum as the intermediate host, and the final hosts are waterfowl. Embryonated Microphallus eggs are ingested from sediment and hatch in the snail's gut, penetrate the intestine, and migrate to the gonads and digestive gland. Following successful establishment, the parasite then undergoes asexual reproduction, replacing much of the host's reproductive tissue and digestive gland, which results in complete sterilization of the snail. The first visible parasite developmental stages (blastocercariae) are detectable after approximately 75 days post-exposure and metacercariae are common by 90 days post-exposure at 16 °C in the lab. The life cycle is completed when snails containing metacercariae are consumed by waterfowl. [2]
Trematoda is a class within the phylum Platyhelminthes. It includes two groups of parasitic flatworms, known as flukes.
Clonorchis sinensis, the Chinese liver fluke, is a liver fluke belonging to the class Trematoda, phylum Platyhelminthes. It infects fish-eating mammals, including humans. In humans, it infects the common bile duct and gall bladder, feeding on bile. It was discovered by British physician James McConnell at the Medical College Hospital in Calcutta (Kolkata) in 1874. The first description was given by Thomas Spencer Cobbold, who named it Distoma sinense. The fluke passes its lifecycle in three different hosts, namely freshwater snail as first intermediate hosts, freshwater fish as second intermediate host, and mammals as definitive hosts.
Microphallus piriformes is a parasitic trematode (fluke). It belongs to the Plagiorchiata, a large suborder of the digenean fluke order Plagiorchiida. M. piriformes is unusual among the flukes in having only one intermediate host rather than two, and no free-swimming cercarian stage.
Trematodes are parasitic flatworms of the class Trematoda, specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions.
The New Zealand mud snail is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae.
Leucochloridium paradoxum, the green-banded broodsac, is a parasitic flatworm. Its intermediate hosts are land snails, usually of the genus Succinea. The pulsating, green broodsacs fill the eye stalks of the snail, thereby attracting predation by birds, the primary host. These broodsacs visually imitate caterpillars, a food source of birds. The adult parasite lives in the bird's cloaca, releasing its eggs into the faeces.
Leucochloridium variae, the brown-banded broodsac, is a species of trematode whose life cycle involves the alternate parasitic invasion of certain species of snail and bird. While there is no external evidence of the worm's existence within the bird host, the invasion of the snail host involves the grotesque swelling of one or both of the snail's eye stalks. This invasion does not cause the snail's death.
Nanophyetus salmincola is a food-borne intestinal trematode parasite prevalent on the Pacific Northwest coast. The species may be the most common trematode endemic to the United States.
Bucephalus polymorphus is a type of flatworm. This species is within the Bucephalidae family of Digenea, which in turn is a subclass of Trematodes within the phylum Platyhelminthes. It is characterized by having a mouth near the middle of its body, along with a sac-like gut. The mouth opening is located in the centre of the ventral surface. This is a specific body type of cecaria known as a gastrostome.
Cerithideopsis californica, common name the California hornsnail or the California horn snail, is a species of sea snail, a marine gastropod mollusk in the family Potamididae. This series was previously known as Cerithidea californica.
Telogaster opisthorchis is an endoparasite in the class Trematoda within the phylum Platyhelminthes. This fluke is known for causing tumor like malformations in fishes by attaching onto its spinal region in the metacercariae form. Malformations cause fish to become more susceptible to fish eating predators allowing T. opisthorchis to continue with its lifecycle.
Clinostomum marginatum is a species of parasitic fluke. It is commonly called the "yellow grub". It is found in many freshwater fish in North America, and no fish so far is immune to this parasite. It is also found in frogs. Clinostomum marginatum can also be found in the mouth of aquatic birds such as herons and egrets. They are commonly present in the esophagus of fish-eating birds and reptiles. Eggs of these trematodes are shed in the feces of aquatic birds and released into water. Aquatic birds become hosts of this parasite by ingesting infected freshwater fish. The metacercariae are found right beneath the skin or in the muscles of host fish.
Philophthalmus gralli, commonly known as the Oriental avian eye fluke, parasitises the conjunctival sac of the eyes of many species of birds, including birds of the orders Galliformes and Anseriformes. In Brazil this parasite was reported in native Anseriformes species. It was first discovered by Mathis and Leger in 1910 in domestic chickens from Hanoi, Vietnam. Birds are definitive hosts and freshwater snail species are intermediate hosts. Human cases of philophthalmosis are rare, but have been previously reported in Europe, Asia, and America.
Coitocaecum parvum is a digeneic trematode or flatworm (Platyhelminthes) that is parasitic to the intestine of the common bully or upland bully. The common and upland bully are freshwater fish of New Zealand that C. parvum uses as its definitive host. C. parvum is a hermaphroditic freshwater trematode that can omit its definitive host and produce eggs by selfing or progenesis inside its amphipod second intermediate host
Microphallus turgidus is a widespread and locally common flatworm parasite in New Zealand lakes and streams. Multilocus allozyme genotype data show that Microphallus turgidus is a single outbred species with high levels of gene flow among South Island populations. Microphallus turgidus is commonly found in the abdominal muscles of grass shrimp.
Alaria is a genus of flatworms, or trematodes, in the family Diplostomidae.
Behavior-altering parasites are parasites with two or more hosts, capable of causing changes in the behavior of one of their hosts to enhance their transmission, sometimes directly affecting the hosts' decision-making and behavior control mechanisms. They do this by making the intermediate host, where they may reproduce asexually, more likely to be eaten by a predator at a higher trophic level which becomes the definitive host where the parasite reproduces sexually; the mechanism is therefore sometimes called parasite increased trophic facilitation or parasite increased trophic transmission. Examples can be found in bacteria, protozoa, viruses, and animals. Parasites may also alter the host behaviour to increase the protection to the parasites or their offspring. The term bodyguard manipulation is used for such mechanisms.
Metagonimus yokogawai is a species of a trematode, or fluke worm, in the family Heterophyidae.
Parorchis acanthus is a parasitic flatworm of the class Trematoda. It is a parasitic castrator of the common periwinkle Littorina littorea. Unlike many trematode species it encysts on hard surfaces and not inside a second intermediate host.
Tylodelphys is a genus of parasitic fluke that infects the small water fish. It induces many behavioral changes on its host. Once inside a fish's eye, it can cause partial blindness and several behavioral changes to the intermediate host. Other species of flukes are able to turn into dormant cysts at certain stages of development, but Tylodelphys spp. stays active and roams free inside the fish's eye, giving it an opportunity for it to induce parasite behavior. When Tylodelphys larvae crawl around the inside of the fish's eye, it can get in between the retina and the lens. This can cause partial blindness to the fish, rendering the fish unable to notice predators. Tylodelphys consists of two species, Tylodelphys clavata and Tylodelphys podicipina Kozicka & Niewiadomska, 1960.
The article incorporates CC-BY-2.0 text from reference. [2]