The Mesozoa are minuscule, worm-like parasites of marine invertebrates. Generally, these tiny, elusive creatures consist of a somatoderm of ciliated cells surrounding one or more reproductive cells.
The opalines are a small group of peculiar heterokonts, currently assigned to the family Opalinidae, in the order Slopalinida. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunlight. Most opalines live in the large intestine and cloaca of anurans, though they are sometimes found in fish, reptiles, molluscs and insects; whether they are parasitic is not certain. The unusual features of the opalines, first observed by Antonie van Leeuwenhoek in 1683, has led to much debate regarding their phylogenetic position among the protists.
Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it forms a synthesis of other disciplines, and draws on techniques from fields such as cell biology, bioinformatics, biochemistry, molecular biology, immunology, genetics, evolution and ecology.
Dicyemida, also known as Rhombozoa, is a phylum of tiny parasites that live in the renal appendages of cephalopods.
Balantidium is a genus of ciliates. It contains the parasitic species Balantidium coli, the only known cause of balantidiasis.
A hydrogenosome is a membrane-enclosed organelle found in some anaerobic ciliates, flagellates, and fungi. Hydrogenosomes are highly variable organelles that have presumably evolved from protomitochondria to produce molecular hydrogen and ATP in anaerobic conditions.
A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called the haustorium, which penetrates the host plant, connecting them to the host vasculature – either the xylem, phloem, or both. For example, plants like Striga or Rhinanthus connect only to the xylem, via xylem bridges (xylem-feeding). Alternately, plants like Cuscuta and some members of Orobanche connect to both the xylem and phloem of the host. This provides them with the ability to extract resources from the host. These resources can include water, nitrogen, carbon and/or sugars. Parasitic plants are classified depending on the location where the parasitic plant latches onto the host, the amount of nutrients it requires, and their photosynthetic capability. Some parasitic plants can locate their host plants by detecting volatile chemicals in the air or soil given off by host shoots or roots, respectively. About 4,500 species of parasitic plants in approximately 20 families of flowering plants are known.
The Zoopagomycotina are a subdivision of the fungal division Zygomycota sensu lato. It contains 5 families and 20 genera. Relationships among and within subphyla of Zygomycota are poorly understood, and their monophyly remains in question, so they are sometimes referred to by the informal name zygomycetes.
Syndinium is a cosmopolitan genus of parasitic dinoflagellates that infest and kill marine planktonic species of copepods and radiolarians. Syndinium belongs to order Syndiniales, a candidate for the uncultured group I and II marine alveolates. The lifecycle of Syndinium is not well understood beyond the parasitic and zoospore stages.
Aggregata is a genus of parasitic alveolates belonging to the phylum Apicomplexa.
Orchitophrya stellarum is a species of single-celled marine ciliates, a member of the class Oligohymenophorea. It is found living freely in the north Atlantic and Pacific Oceans but is also parasitic, being found inside the gonads of starfish.
Pasteuria is a genus of mycelial and endospore-forming, nonmotile gram-positive bacteria that are obligate parasites of some nematodes and crustaceans. The genus of Pasteuria was previously classified within the family Alicyclobacillaceae, but has since been moved to the family Pasteuriaceae.
Pseudorhabdosynochus is a genus of monopisthocotylean monogeneans, included in the family Diplectanidae. The type-species of the genus is Pseudorhabdosynochus epinepheli .
Lipotropha is a genus of parasitic alveolates of the phylum Apicomplexa.
Chromidina elegans is a species of parasitic ciliates. It is a parasite of the cuttlefish Sepia elegans.
Sepia elegans, the elegant cuttlefish, is a species of cuttlefish in the family Sepiidae from the eastern Atlantic Ocean and the Mediterranean Sea. It is an important species for fisheries in some parts of the Mediterranean where its population may have suffered from overfishing.
Chromidina elegans is a species of ciliates, described in 2016. It is parasitic in the kidney appendages of the cuttlefish Loligo vulgaris. The type-locality is off Tunisia in the Mediterranean Sea.
Jean-Lou Justine, French parasitologist and zoologist, is a professor at the National Museum of Natural History in Paris, France, and a specialist of fish parasites and invasive land planarians.
An oncomiracidium is the ciliated and free-living larva of a monogenean, a type of parasitic flatworm commonly found on fish. It is similar to the miracidium of Trematoda, but has sclerotised (hardened) hooklets not found in the latter.
Microcotyle sebastis is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.
