''Anoplocephala manubriata'' is a host-specific

tapeworm Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda (the other subclass is Cestodaria). Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodar ...

, or ''cestode'', that parasitizes African (''

Loxodonta africana The African bush elephant (''Loxodonta africana'') is one of two extant African elephant species and one of three extant elephant species. It is the largest living terrestrial animal, with bulls reaching a shoulder height of up to and a body ...

'') and Asian (''

Elephas maximus ''Elephas'' is one of two surviving genera in the family of elephants, Elephantidae, with one surviving species, the Asian elephant, ''Elephas maximus''. Several extinct species have been identified as belonging to the genus, extending back to ...

'') elephants. These parasites require intermediate and definitive

hosts A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places *Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman *Michel Host ( ...

to complete its

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring *Life-cycle hypothesis, ...

. ''A. manubriata'' causes

gastrointestinal The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

in elephants. When ingested in the elephant, the cestode is attached to the intestinal mucosae. The life cycle of ''A. manubriata'' have not been completely elucidated, however studies have shown through examining oribatid

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

s from a dung pile near an elephant site that an immature stage exists. The study concluded at least five species were contained at least one immature life stage of the cestode. Studies have shown that ''Anoplocephala manubriata'' is closely related to another ''

Anoplocephala ''Anoplocephala'' is a genus of tapeworms in the family Anoplocephalidae named in 1848 by Émile Blanchard. The type species is ''Anoplocephala perfoliata ''Anoplocephala perfoliata'' is the most common intestinal tapeworm of horses, and an ag ...

'' species called ''

Anoplocephala perfoliata ''Anoplocephala perfoliata'' is the most common intestinal tapeworm of horses, and an agent responsible for some cases of equine colic. Description Between 8 and 25 centimeters long, ''Anoplocephala perfoliata'' is part of the order Cyclophilli ...

'', which is a host-specific tapeworm to

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...

Phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis of the second

internal transcribed spacer Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. I ...

region (ITS-2), a portion of the 28S region and

cytochrome c oxidase subunit I Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I (MT-CO1) is a protein that in humans is encoded by the ''MT-CO1'' gene. In other eukaryotes, the gene is called ''COX1'', ''CO1'', or ''COI''. Cytochrom ...

(COX1) genes verified its relationship. Asian elephants have a high prevalence for ''

Strongylidae Strongyles (from the Greek ''strongulos'', meaning round), or alternatively, strongyls, are nematode worms of the family Strongylidae, order Strongylida. They are often parasitic in the gastrointestinal tract of mammals, especially grazers such ...

'' and ''Anoplocephala'' spp. infection.

Hosts

Oribatid mites, the intermediate hosts, are a large group of free-living,

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

-dwelling

acari Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

nes. They have low

fecundity Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...

and life development varies from months to 2 years in temperate soils. They are of economic importance to parasites by increasing the breakdown organic material in soil. There are more than 6 species of oribatid mites ('' Galumna racilis'', '' Kilimabates pilosus'', '' Kilimabates'' sp., '' Scheloribates fusifer'', '' Muliercula ngoyensis'' and '' Zygoribatula undulata''). Elephants, the definitive hosts, acquires infection by eating oribatid mites. Elephants who have gastrointestinal problems are more likely to acquire an ''A. manubriata'' parasitic infection by accidentally swallowing infected oribatid mites in the dirt the elephants dwell in. These elephants would excrete

feces Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

containing the cestode into the dirt, where other elephants can come in contact with the infected mite, adding to the prevalence of infected elephants.

Typology and Morphology

Adult ''A. manubriata'' are white in color. They also contain strobila that stretch out towards the posterior end of the organism that range from 0.7 cm to 1.8 cm long. The anterior end of the worm contains a scolex, which has a circumference of approximately 1.5 to 2.1 cm. This scolex contains four large oral suckers and does not have hooks or rosetellum. The proglottids of the worms contain both longitudinal and traverse muscles; this was determined by microscopic evaluation. The proglottid is divided into two distinct compartments called the cortex and medulla.

Pathology

* Symptoms: Clinical signs of infection are

anorexia Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...

, mud eating, and general deterioration of the body. * Diagnosis: Infected elephants are not tested for the infection until they have died, which then an

autopsy An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any di ...

of the elephant is taken to test if it was infected for research purposes. * Treatment: There is no treatment for ''A. manubriata'' infection in elephants.

Phylogeny – species & hosts

*'' Anoplocephala magna'' – infects

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s. Occurs worldwide, more frequent in

USA The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, less in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. *''Anoplocephala manubriata'' – infects elephants. *'' Anoplocephala perfoliate'' - infects horses. Causes

horse colic Colic in horses is defined as abdominal pain, but it is a clinical symptom rather than a diagnosis. The term colic can encompass all forms of gastrointestinal conditions which cause pain as well as other causes of abdominal pain not involving the g ...

. *'' Anoplocephala plicata'' - same as A. magna

References

External links

** {{Taxonbar, from=Q42332994 Cestoda Animals described in 1914