Moniezia expansa is primarily present throughout ungulates of Europe, Asia, Africa, America and Australia. This parasite has also been found in South American countries, including Peru and Argentina. (Beveridge, et al., 1994; Gomez-Puerta and Denegre, 2008)
Moniezia expansa occupies three different environments during its life cycle: the external environment, the body cavity of the intermediate host (oribatid mite), and the intestine of the definitive host (ungulate). First, the eggs of M. expansa exist in the external environment until accidentally ingested by the intermediate host, an oribatid (ground living) mite. The eggs of M. expansa exist in ungulates' feces, most regularly in pastures where these animals feed. The oribatid mite occupies the first inch of turf-hiding during the day, and searching for food at night. Moniezia expansa eggs will then grow and develop to adults in the oribatid mite’s body cavity. Through ingestion of the oribatid mite by ungulates, the adult M. expansa is able to feed on nutrients in the host’s intestine. (Barriga, 1994; Olsen, 1986; Stunkard, 1939)
Like all cestodes, or tapeworms, M. expansa are flat with multiple segments of proglottids, used for producing gametes for reproduction. The adult bodies lack digestive tracts and are covered in microvilli to increase surface area for the absorption of nutrients. Moniezia expansa adults can reach lengths of 4 to 5 meters and are separated into three sections including the scolex, neck and strobila. The scolex is usually less than 1 millimeter, and contains suckers and hooks to assist in holding on to the host. The small neck produces immature proglottids, while the large strobila (main body) consists of a large chain of mature male and female proglottids. The size of M. expansa larvae vary throughout its life cycle, containing hooks to dispel the egg. (Brusca and Brusca, 1990; Chilton, et al., 2007; Elliot, 1993; Stunkard, 1939)
Moniezia expansa can be distinguished from a similar species, Moniezia benedeni, through the patterns of interproglottidal glands. In M. expansa these glands from a rosette pattern around depressions into the posterior surface while M. benedeni glands are linear. (Taylor, 1928)
The life cycle of M. expansa begins with the development of the oncosphere, a six-hooked larva, inside the cuticle of the egg. Following the consumption of mature eggs by the intermediate host (oribatid mite) the oncosphere emerges through destruction in the egg’s cuticle caused by the host’s mouth parts. The oncosphere is then able to invade the intestinal wall of the mite and continue growth into an invasive cysticercoid larva in the mite’s body cavity, or hemocoel. By 15 to 18 weeks fully developed cysticercoids are formed. The oribatid mite is then consumed by the definitive host (ungulate) where further development into the adult occurs in the intestine. The life cycle is completed through the release of proglottids, containing eggs, in the ungulate’s feces. Eggs are able to survive on their own, without ingestion by the intermediate host, for less than one day. (Barriga, 1994; Olsen, 1986; Stunkard, 1939)
Moniezia expansa does not have a complex mating system.
The strobila of Moniezia expansa, which contain chains of mature male and female proglottids, allow for reproduction within a proglottid or copulation with other proglottids and proglottids of other tapeworms. Once reproduction has occurred, proglottids containing fertilized eggs (gravid proglottid) will reach the end of the strobila and detach into the host feces. (Melhorn, 2001)
Mass amounts of eggs must be produced to counter high mortality seen in the egg and larval form. This is caused by environmental conditions and the absence of ingestion by the intermediate and definitive host. (Olsen, 1986)
Moniezia expansa shows no parental investment.
The lifespan/longevity of Moniezia expansa has not been studied.
Moniezia expansa has sensory organs characteristic of organisms in the class Cestoda. These consist of general sensory organs for tactile stimulation and are located in the scolex where longitudinal nerves then extend down the body. (Brusca and Brusca, 1990)
Cestodes, including Moniezia expansa contain no digestive system, and therefore absorb nutrients from the host’s intestine through their tegument, or external covering. Projections of microvilli aid in the absorption of nutrients through an increase in surface area. (Brusca and Brusca, 1990)
Moniezia expansa are not predatory or preyed upon directly.
Moniezia expansa can be found in the intermediate host, an oribatid mite, or in the small intestine of the definitive host, sheep and cattle. This parasite's most important impact on the community is seen through the infection of sheep or cattle with Moniezia expansa which can cause stockbreeding losses through diarrhea and flesh loss. There have also been reports of Moniezia expansa in the domestic pig in Peru. (Chilton, et al., 2007; Elliot, 1993; Gomez-Puerta and Denegre, 2008)
There are no known positive effects of Moniezia expansa on humans.
Although Moniezia expansa does not directly negatively affect humans, it can indirectly affect humans through the loss of cattle and sheep. The stockbreeding loss associated with infection of M. expansa in cattle and sheep can cause an economic loss affecting humans with an income based on cattle and sheep.
Andrea Smith (author), University of Michigan-Ann Arbor, Heidi Liere (editor), University of Michigan-Ann Arbor, John Marino (editor), University of Michigan-Ann Arbor, Barry OConnor (editor), University of Michigan-Ann Arbor, Renee Mulcrone (editor), Special Projects.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the southern part of the New World. In other words, Central and South America.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
living in landscapes dominated by human agriculture.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
either directly causes, or indirectly transmits, a disease to a domestic animal
uses smells or other chemicals to communicate
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
fertilization takes place within the female's body
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
the area in which the animal is naturally found, the region in which it is endemic.
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
breeding takes place throughout the year
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Brusca, R., G. Brusca. 1990. Invertebrates. Sunderland, MA: Sinauer Associates.
Chilton, N., M. O'Callaghan, I. Beveridge, R. Andrews. 2007. Genetic markers to distinguish Moniezia expansa from M. benedeni. Parasitology Research, 100: 1187.
Elliot, D. 1993. Tapeworm (Moniezia expansa) and its effect on sheep production: the evidence reviewed. New Zealand Veterinary Journal, 106 (4): 429-440.
Gomez-Puerta, , Denegre. 2008. Occurrence of Moniezia expansa in dometic pig. Veterinary Parasitology, 33: 191-194.
Melhorn, H. 2001. Encyclopedic Reference of Parasitology. Berlin: Springer.
Olsen, O. 1986. Animal parasites: their life cycles and ecology. Baltimore, MD: University Park Press.
Stunkard, H. 1939. The development of Moniezia expansa in the intermediate host. Parasitology, 30: 491-501.
Taylor, E. 1928. Moniezia, a genus of cestode worms, and the proposed reduction of its species to three. Proceedings of the US Natational Museum, 74: 1-9.