(A. V. Ivanov, 1945)
Parenteroxenos dogieliA. V. Ivanov, 1945
Thyonicola dogieli is a parasitic species of gastropod mollusc in the family Eulimidae. It parasitises sea cucumbers in the northeastern Pacific Ocean.
In evolutionary biology, parasitism is a relationship between species, where one organism, the parasite, lives on or in another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism, trophically transmitted parasitism, vector-transmitted parasitism, parasitoidism, and micropredation.
The gastropods, more commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca, called Gastropoda. This class comprises snails and slugs from saltwater, from freshwater, and from the land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs.
Mollusca is the second largest phylum of invertebrate animals. The members are known as molluscs or mollusks. Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species.
This slender elongated mollusc does not have a shell and takes the form of a long tube, coiled like a spring, or tied in knots, and filled with eggs. 128 cm (50 in) long when uncoiled.It holds the record as the longest gastropod mollusc in the world, one individual having been found to be
Thyonicola dogieli is a parasite of sea cucumbers such as Cucumaria miniata .It inhabits the gut of the sea cucumber, being attached at the anterior end. It has no digestive tract and absorbs nutrients through its cuticle. It is a hermaphrodite; the testis is located near the anterior end and the ovary near the posterior end (this enables the sperm to be carried to the eggs amid the flow of the contents of the host's gut). The body is filled with maturing eggs enclosed in cocoons. When the veliger larvae, which have miniature coiled shells and operculums, are sufficiently developed, the cocoons are released into the sea cucumber's gut and pass out into the sea with its faeces.
Cucumaria miniata is commonly known as the orange sea cucumber or red sea cucumber due to its striking color. This northeast Pacific species is often found wedged in between rocks or crevices at the coast or on docks and can generally be identified by its orange bushy tentacles protruding above the substrate.
In biology, a hermaphrodite is an organism that has complete or partial reproductive organs and produces gametes normally associated with both male and female sexes. Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the "female" or "male." For example, the great majority of tunicates, pulmonate snails, opisthobranch snails, earthworms and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites.
A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells.
On encountering sea water the cocoons burst open and the free-living larvae are liberated. They are about 0.1 mm (0.004 in) long, and unless swallowed by a sea cucumber, they will soon die, However, any that are ingested undergo metamorphosis in the host's gut, lose their shell and mantle and burrow into the wall of the gut with the aid of a glandular secretion. As the juvenile mollusc grows, its posterior end pushes its way into the sea cucumber's body cavity, and the gonads develop, the interior of the mollusc becoming a brood pouch.
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Metamorphosis is iodothyronine-induced and an ancestral feature of all chordates. Some insects, fishes, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals that go through metamorphosis are called metamorphoses. Animals can be divided into species that undergo complete metamorphosis ("holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis ("ametaboly").
Acanthocephala is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host. Acanthocephalans have complex life cycles, involving at least two hosts, which may include invertebrates, fish, amphibians, birds, and mammals. About 1420 species have been described.
Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothurian species worldwide is about 1,717 with the greatest number being in the Asia Pacific region. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, namako, bêche-de-mer or balate. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter after which bacteria can continue the degradation process.
Trematoda is a class within the phylum Platyhelminthes. It includes two groups of parasitic flatworms, known as flukes.
Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults are particularly common in the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.
The Aspidogastrea is a small group of flukes comprising about 80 species. It is a subclass of the trematoda, and sister group to the Digenea. Species range in length from approximately one millimeter to several centimeters. They are parasites of freshwater and marine molluscs and vertebrates. Maturation may occur in the mollusc or vertebrate host. None of the species has any economic importance, but the group is of very great interest to biologists because it has several characters which appear to be archaic.
Taenia saginata, commonly known as the beef tapeworm, is a zoonotic tapeworm belonging to the order Cyclophyllidea and genus Taenia. It is an intestinal parasite in humans causing taeniasis and cysticercosis in cattle. Cattle are the intermediate hosts, where larval development occurs, while humans are definitive hosts harbouring the adult worms. It is found globally and most prevalently where cattle are raised and beef is consumed. It is relatively common in Africa, Europe, Southeast Asia, South Asia, and Latin America. Humans are generally infected as a result of eating raw or undercooked beef which contains the infective larvae, called cysticerci. As hermaphrodites, each body segment called proglottid has complete sets of both male and female reproductive systems. Thus, reproduction is by self-fertilisation. From humans, embryonated eggs, called oncospheres, are released with faeces and are transmitted to cattle through contaminated fodder. Oncospheres develop inside muscle, liver, and lungs of cattle into infective cysticerci.
Ascaridia galli is a parasitic roundworm belonging to the phylum Nematoda. Nematodes of the genus Ascaridia are essentially intestinal parasites of birds. A. galli is the most prevalent and pathogenic species, especially in domestic fowl, Gallus domesticus. It causes ascaridiasis, a disease of poultry due to heavy worm infection, particularly in chickens and turkeys. It inhabits the small intestine, and can be occasionally seen in commercial eggs.
Trivia monacha, also known as the European cowrie or spotted cowrie, is a species of small sea snail, a marine gastropod mollusc in the family Triviidae, the trivias.
Leeches are segmented parasitic or predatory worms that belong to the phylum Annelida and comprise the subclass Hirudinea. They are closely related to the oligochaetes, which include the earthworms, and like them have soft, muscular, segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having external annulations that do not correspond with their internal segmentation. The body is relatively solid, and the spacious body cavity found in other annelids, the coelom, is reduced to small channels.
Cyclotorna monocentra is a moth of the family Cyclotornidae. It is found in Australia.
Psychropotes longicauda is a species of sea cucumber in the family Psychropotidae. It inhabits the deep sea where the adult is found on the seabed. The larva is pelagic and has an appendage shaped like a sail on its back which may enable it to move through the water.
Entovalva nhatrangensis is a species of small marine bivalve mollusc in the family Lasaeidae. It was first described in 2010 and its specific name "nhatrangensis" derives from the locality where it was originally found, Nha Trang Bay in Vietnam. It lives inside the oesophagus of certain species of sea cucumbers. It is considered to be an endosymbiont rather than a parasite because it does not harm its host.
Holothuria leucospilota, commonly known as the black sea cucumber/ Black tarzan, is a species of marine invertebrate in the family Holothuriidae. It has been placed in the subgenus Mertensiothuria making its full scientific name Holothuria (Mertensiothuria) leucospilota. It is the type species of the subgenus and is found on the seabed in shallow water in the Indo-Pacific.
Berghia stephanieae is a species of sea slug, an aeolid nudibranch. It is a marine gastropod mollusc in the family Aeolidiidae. It was previously known as Aeolidiella stephanieae.
Thyonicola americana is a species of parasitic sea snail, a marine gastropod mollusc in the family Eulimidae. It infests the sea cucumbers Eupentacta quinquesemita and Eupentacta pseudoquinquesemita in Puget Sound and other parts of the northeastern Pacific Ocean.
Eupentacta quinquesemita is a species of sea cucumber, a marine invertebrate with an elongated body, a leathery skin and tentacles surrounding the mouth. It is commonly known as the stiff-footed sea cucumber or white sea cucumber, and occurs on rocky coasts in the northeastern Pacific Ocean.
Australamphilina elongata is a species of parasitic worm in the order Amphilinidea. Amphilinids are commonly considered to be tapeworms, yet differ from true tapeworms, subclass Eucestoda, because their bodies are unsegmented and are not divided into proglottids. It is an internal parasite of freshwater turtles including the eastern long-necked turtle. It is found in eastern Australia.
Lithophaga simplex is a species of bivalve mollusc in the family Mytilidae. It is a boring species, tunnelling into living coral colonies. It can be found in the tropical western central Pacific Ocean.
Lottia instabilis is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae. Common names include the unstable limpet, the unstable seaweed limpet and the rocking chair limpet. It is native to the northern Pacific Ocean where it feeds on kelp in the intertidal zone and the shallow sub-littoral zone.
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