The Apicomplexa are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an apicoplast—with an apical complex membrane. The organelle's apical shape is an adaptation that the apicomplexan applies in penetrating a host cell.
The flatworms, flat worms, Platyhelminthes, or platyhelminths are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Being acoelomates, and having no specialised circulatory and respiratory organs, they are restricted to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion and egestion ; as a result, the food can not be processed continuously.
Rhynchobdellida, the jawless leeches or freshwater leeches, are an order of aquatic leeches. Despite the common name "freshwater leeches", species are found in both sea and fresh water. They are defined by the presence of a protrusible proboscis instead of jaws, and having colourless blood. They move by "inchworming" and are found worldwide. The order contains 110 species, divided into 41 genera and three families. Members of the order range widely in length, usually between 7 and 40 mm. They are hermaphrodite. The order is not monophyletic.
Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda. Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodaria. All tapeworms are endoparasites of vertebrates, living in the digestive tract or related ducts. Examples are the pork tapeworm with a human definitive host, and pigs as the secondary host, and Moniezia expansa, the definitive hosts of which are ruminants.
The Clitellata are a class of annelid worms, characterized by having a clitellum – the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
Haemadipsidae are a family of jawed leeches. They are a monophyletic group of hirudiniform proboscisless leeches. These leeches have five pairs of eyes, with the last two separated by two eyeless segments. The family is monotypic, containing only the subfamily Haemadipsinae, though as the family can apparently be divided into two or three distinct lineages, at least one of the proposed splits, while not a distinct family, might be a valid subfamily.
The longtail stingray, is a species of stingray in the family Dasyatidae, found in the eastern Pacific Ocean from Baja California to Colombia. It inhabits sandy habitats down to a depth of 90 m (300 ft). Measuring up to 1.56 m (5.1 ft) across, this species has a rhomboid pectoral fin disc, a lower fin fold on the tail, and numerous dermal denticles along the back and behind the stinging spine. The longtail stingray feeds mainly on bottom-dwelling bony fishes and crustaceans. It is aplacental viviparous, with females giving birth to 1–5 young in late summer. It is caught for food, likely throughout its range, but specific fishery data is lacking.
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, 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 ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels.
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish infecting parasites.
Tyrannobdella is a monotypic genus of leech, of family Praobdellidae, found in South America in the upper reaches of the Amazon. This newly found genus of leech takes sustenance from the mucous membranes of the mammalian upper respiratory tract, and is known to feed upon humans. It has eight teeth. Tyrannobdella rex was discovered feeding upon the mucous membrane of a girl who had recently bathed in the upper Amazon in Peru.
Erpobdella is a genus of leeches in the family Erpobdellidae. Members of the genus have three or four pairs of eyes, but never have true jaws, and are typically 20–50 millimetres (0.8–2.0 in) long. All members do not feed on blood, but instead are predators of small aquatic invertebrates, which they often swallow whole.
Klaus Rohde is a German biologist and parasitologist at the University of New England (UNE), Australia. He is known particularly for his work on marine parasitology, evolutionary ecology, zoogeography, phylogeny, and ultrastructure of lower invertebrates.
The annelids, also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments.
Erpobdella octoculata is a freshwater leech in the Erpobdellidae family. This species can be found in Europe, the Mediterranean, and the Middle East.
The Piscicolidae are a family of jawless leeches in the order Rhynchobdellida that are parasitic on fish. They occur in both freshwater and seawater, have cylindrical bodies, and typically have a large, bell-shaped, anterior sucker with which they cling to their host. Some of the leeches in this family have external gills, outgrowths of the body wall projecting laterally, the only group of leeches to exchange gases in this way.
Acanthobdella peledina is a species of leech-like clitellate in the order Acanthobdellida. It feeds on the skin and blood of freshwater fishes in the boreal regions of northern Europe, Asia and North America.
Mary Morgan-Richards is a New Zealand biologist, and as of 2019 is a full professor at Massey University.
Macrobdella is a genus of leeches native to freshwater ecosystems of North America, especially Canada, Mexico, and the United States. The genus is commonly referred to as North American medicinal leeches.
Praobdellidae is a family of hematophagous leeches which live on the mucous membranes of mammals and sometimes invertebrates. These are internal parasites that enter the body through natural orifices, and cause hirudiniases.
Janine Caira Ph.D., is an academic researcher specializing in the taxonomy, evolution and diversity of tapeworms that live in the digestive tract of sharks and stingrays. Related work includes applying the practice of categorizing groups of organisms based on their most recent common ancestor to advance the phylogenetic systematics of tapeworms and demonstrating the importance of accurate host identification. She is a Board of Trustees Distinguished Professor in the Department of Ecology & Evolutionary Biology at the University of Connecticut.
