Diphyllobothrium mansonoides

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Geographic Range

Diphyllobothrium mansonoides is typically found in the southern United States, especially in Florida and along the Gulf Coast. (Mueller, et al., 1963)

Habitat

The habitat for eggs, coracidia, and copepod host, is freshwater. Plerocercoid can be found in the muscles of vertebrates. The adult Diphyllobothrium mansonoides inhabit the gut of cats. (Mueller, et al., 1963)

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Physical Description

Diphyllobothrium mansonoides has a small spatulate scolex (head region), which is set off from its long slender neck. The bothria, which are longitudinal grooves, are shallow, broad, flat bottomed, and continuous with the surface of the neck. Posterior to the neck are a number of immature proglottids, anywhere between 200 to 300. Mature proglottids with eggs tend to occur 16 to 20 cm posterior to the scolex and have a maximum width of 7 mm (Mueller, 1935). Diphyllobothrium mansonoides uterus is in the form of a spiral and forms two terminal loops(Mueller, 1932). The muscular terminal compartment of D. mansonoides is set off by a sphincter (Mueller, 1935). The spiraled outer uterine coils is a major characteristic of D. mansonoides. The cirrus and vagina open separately (Mueller, 1936). The cirrus opens as a small pore, while the vagina posterior to it, appears as a transverse slit (Jubliar, 1951; Mueller, 1935). The testes are numerous, spherical, and are located in median plane of proglottid. The eggs are pointed, another major characteristic for D. mansonoides (Mueller, 1932). Their coracidium larvae have recognizable hooks (Mueller, 1936). (Jubilar, 1951; Mueller, 1932; Mueller, 1935; Mueller, 1936)

Development

The eggs of D. mansonoides hatch between 9 to 120 days (Mueller, 1938). The coracidium or first larval stage exit the egg through the operculum or cap. During this stage, the coraciduim is ciliated and swims about in the water until it is ingested by a copepod, typically a species of Cyclops (Mueller, 1938). In the gut of the Cyclops, the ciliated epithelium is shed exposing the hooks on the cercomer (Mueller, 1938). The cercomer is the posterior adhesive organ. Through the use of its hooks, the larva penetrates the midgut wall and develops into an infective procercoid after 18 days (Mueller, 1938). The development of the procercoid causes the copepods to be more sluggish and therefore more susceptible to be eaten by a second intermediate host such as a frog, snake, or mammal (Mueller, 1936). When the Cyclops is eaten by an appropriate fish, the larva penetrates the wall of the gut and enters the muscles or connective tissues of the fish. In the muscles or connective tissues the procercoid larva transforms into the plerocercoid. The plerocercoid lacks hooks. It is during this stage that the bothria (longitudinal groves on the scolex) develops, but there is no strobilization. The plerocercoids may pass through several paratenic hosts. The infected intermediate host could then be eaten by its definitive host, the bobcat, or secondary definitive hosts: cat or dog (Mueller, 1936). Once eaten by the definitive host or secondary definitive host, plerocercoids penetrate the intestinal wall and take up residence in the muscles where they absorb nutrients (Mueller, 1938). (Mueller, 1936; Mueller, 1938)

Reproduction

This species is a hermaphrodite.

  • Key Reproductive Features
  • simultaneous hermaphrodite
  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning

Behavior

Communication and Perception

Cestodes in general have sensory organs in the scolex, which are attached to longitudinal nerves extending down the body. The nerves are attached to organs and the cestodes can detect tactile stimulation.

Food Habits

Diphylobothrium mansonoides obtain food by absorbing nutrients from their host.

Predation

These parasites are likely not intentionally ingested. Larval mortality is high due to the parasites not reaching a definitive host.

Ecosystem Roles

This species uses copepods, fish and frogs intermediate hosts. Mammals are usually second definitive hosts.

Species Used as Host

Economic Importance for Humans: Negative

Humans rarely become infected with the procercoid by accidentally eating the copepods. When this does occur, the procercoid migrates to subcutaneous tissue or muscles: the pleural cavity, abdominal viscera, urinary tract, scrotum, and the eye, where they develop into the plerocercoid. The human condition of having plerocercoid in the muscles and subcutaneous tissues is called sparganosis. Sparganosis is a very rare parasitic disease that produces chronic active inflammation in the brain. Possible routes of human infestation are as follows: 1) ingestion of water contaminated with copepods; 2) ingestion of raw second intermediate hosts, such as snake or frog; 3) topical application of a slice of raw meat to open wounds and mucous membranes; and 4) ingestion of the plerocercoid larvae through carriers. Symptoms include itching, hives and pain at the site where the nodules are developing. The treatment is usually surgical removal of the nodules containing the third stage larvae. (Dong, et al., 1996)

Contributors

Renee Sherman Mulcrone (editor).

Susan Kais (author), University of Michigan-Ann Arbor, Barry OConnor (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

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.

causes disease in humans

an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

freshwater

mainly lives in water that is not salty.

heterothermic

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.

parasite

an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

tactile

uses touch to communicate

temperate

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).

References

Brusca, R., G. Brusca. 2003. Invertebrates. Sunderland, Massachusetts: Sinauer Associates, Inc..

Dong, G., H. Sun, K. Chang, K. Wang, H. Jung. 1996. Cerebral sparganosis: clinical manifestations, treatment, and outcome. Journal of Nerosurgery, 85: 1066-1071.

Jubilar, L. 1951. Spargana from the Florida alligator. Journal of Parasitology, 37: 317-318.

Mueller, J. 1935. A Diphyllobothrium from cats in dogs in the Syracuse region. Journal of Parasitology, 21: 114-120.

Mueller, J. 1932. A Diphyllobothrium from cats in the Syracuse region.. Journal of Parasitology, 19: 140-141.

Mueller, J. 1936. A repartition of the genus Diphyllobothrium. Journal of Parasitology, 22: 471-478.

Mueller, J. 1938. The life history of Diphyllobothrium mansonoides Mueller 1935, and some consideractions with regard to sparganosis in the United States. American Journal of Tropical Medicine, 18: 41-56.

Mueller, J., E. Hart, W. Walsh. 1963. Human sparganosis in the United States. Journal of Parasitology, 49: 294-309.