A sclerite is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly to the hardened parts of arthropod exoskeletons and the internal spicules of invertebrates such as certain sponges and soft corals. In paleontology, a scleritome is the complete set of sclerites of an organism, often all that is known from fossil invertebrates.
Vestigiality is the retention during the process of evolution of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species.
Monogeneans 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.
Cichlidogyrus is a genus of monopisthocotylean monogeneans in the family Ancyrocephalidae. The type-species of the genus is Cichlidogyrus arthracanthusPaperna, 1960, by original designation. All the species of the genus are parasites on the gills of fish, namely African Cichlidae, Nandidae and Cyprinodontidae.
Protomicrocotylidae is a family of monogenean parasites in the order Mazocraeidea.
Lethacotyle is a genus of polyopisthocotylean monogeneans, included in the family Protomicrocotylidae.
The genus includes only two species: Lethacotyle fijiensisManter & Price, 1953 , the type-species of the genus, and Lethacotyle veraJustine, Rahmouni, Gey, Schoelinck, & Hoberg, 2013 . Both species are parasitic on the gills of jacks in the Pacific Ocean. They are known only from three localities: off Fiji, Andaman Islands, and New Caledonia.
The genus Lethacotyle is special in that its members have no clamps on their posterior attachment organ or haptor, in contrast to most polyopisthocotylean Monogenean which have clamps. This is reflected in the etymology of the name, which, according to Manter & Price is "from letha = forgetting, and cotyle = cup, and refers to the absence of clamps".
Lethacotyle fijiensis is a species of monogeneans of the family Protomicrocotylidae.
Lethacotyle vera is a species of monogenean of the family Protomicrocotylidae.
The haptor is the attachment organ of the monogeneans, a group of parasitic Platyhelminthes. The haptor is sometimes called opisthaptor to emphasize that it is located in the posterior part of the body, and to differentiate it from the prohaptor, a structure including glands located at the anterior part of the body. According to Yamaguti (1963), the chief adhesive organ of the monogeneans, the haptor, is posterior, more or less discoid, muscular, may be divided into alveoli or loculi, is usually provided with anchors, has nearly always marginal larval hooklets, or is in a reduced form with anchors. The haptor may consist of symmetrical or asymmetrical, sessile or pedunculate, muscular suckers or clamps with or without supporting sclerites; accessory adhesive organs may be present in form of armed plaques, lappets or appendices.
Pseudorhabdosynochus is a genus of monopisthocotylean monogeneans, included in the family Diplectanidae. The type-species of the genus is Pseudorhabdosynochus epinepheli .
Lee Hong Susan Lim, more commonly known as Susan Lim, was a Malaysian parasitologist who specialised on the Monogenea, a class of parasitic flatworms which are important ectoparasites of fishes. She was the first and only Malaysian commissioner elected to the International Commission on Zoological Nomenclature. Her research was mainly in the fields of taxonomy and faunistics, although in later years, she became involved in a wide range of parasitological disciplines.
Pseudorhabdosynochus firmicoleatus is a diplectanid monogenean parasite on the gills of the Yellowedge grouper, Epinephelus flavolimbatus and the Snowy grouper, Epinephelus niveatus. It was described by Kritsky, Bakenhaster and Adams in 2015.
Hexabothriidae is a family of monogenean parasites. The family name was proposed by Emmett W. Price in 1942. The family includes 14-16 genera according to authors and about 60 species; all are parasitic on the gills of chondrichthyan fishes.
Plectanocotylidae is a family of polyopisthocotylean monogeneans. All the species in this family are parasitic on the gills of marine fish.
Chimaericola leptogaster is a species of polyopisthocotylean monogenean in the family Chimaericolidae. It is ectoparasitic on the gills of the chimaera Chimaera monstrosa.
Microcotyle longirostri is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.
Microcotyle danielcarrioni is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.
Microcotyle moyanoi is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.
Pseudaxine trachuri is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Gastrocotylidae.
Sibitrema is a genus which belongs to the phylum Platyhelminthes and class Monogenea; the only species included in this genus is parasite of fish.
