Griphobilharzia amoena

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Griphobilharzia amoena
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Family:
Subfamily:
Griphobilharziinae

Platt, Blair, Purdie & Melville, 1991
Genus:
Griphobilharzia

Platt, Blair, Purdie & Melville, 1991
Species:
G. amoena
Binomial name
Griphobilharzia amoena
Platt, Blair, Purdie & Melville, 1991

Griphobilharzia amoena is a significant trematode that infect crocodiles such as the Australian freshwater crocodile, Crocodylus johnstoni , located in Darwin, Australia with reported illness in Irian Jaya as well. [1] They possess a distinctive tegument that is composed of two lipid bilayers instead of a single bilayer. The double bilayer may be an adaptation to survive the host's immune response. [2]

Contents

Description

The life cycle remains unknown but cercariae probably develop in mollusks, most likely gastropods. [3] Its intermediate host could be freshwater snails from family Planorbidae. [4]

Griphobilharzia amoena are dioecious and are found in the circulatory system of their definitive host, Crocodylus johnstoni. [1] The male has a gynecophoric chamber that extends two-thirds of the acetabulum to testis. Females are oriented anti-parallel to the males and are completely enclosed in the gynecophoric chamber. The nature of the physical relationship between the sexes is unclear. The worms are hematophagous, even the female, despite being fully enclosed. [1]

Evolution

The notion that Griphobilharzia amoena is the only schistosome found in a cold-blooded animal (crocodile), leads to the hypothesis that perhaps Griphobilharzia amoena and other schistosomes are based in ectothermic archosaurs. [5] It was also predicted that since Griphobilharzia amoena originated in ectotherms and then inhabited endothermic avian species, which is where they exist today. [5] Brant and Loker used endothermy as a key factor in the diversification of schistosomes. However, upon analysis it was discovered that Griphobilharzia amoena is actually more closely related to spirorchiids from freshwater turtles rather than to schistosomes. [5]

Related Research Articles

Crocodile Subfamily of large reptilian carnivores

Crocodiles or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans, the gharial and false gharial among other extinct taxa.

Trematoda Class of parasitic flatworms

Trematoda is a class within the phylum Platyhelminthes. It includes two groups of parasitic flatworms, known as flukes.

<i>Schistosoma</i> Genus of flukes

Schistosoma is a genus of trematodes, commonly known as blood flukes. They are parasitic flatworms responsible for a highly significant group of infections in humans termed schistosomiasis, which is considered by the World Health Organization as the second-most socioeconomically devastating parasitic disease, with hundreds of millions infected worldwide.

Digenea Class of flukes

Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.

American crocodile Species of crocodile endemic to the Neotropics

The American crocodile is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida and the coasts of Mexico to as far south as Peru and Venezuela.

Freshwater crocodile Species of reptile

The freshwater crocodile, also known as the Australian freshwater crocodile, Johnstone's crocodile or also known as freshie, is a species of crocodile endemic to the northern regions of Australia. Unlike their much larger Australian relative, the saltwater crocodile, freshwater crocodiles are not known as man-eaters, although they bite in self defence, and brief, nonfatal attacks have occurred, apparently the result of mistaken identity.

Schistosomatidae Family of flukes

Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus Schistosoma, infect and cause disease in humans. Other genera which are infective to non-human vertebrates can cause mild rashes in humans.

<i>Trichobilharzia regenti</i> Species of fluke

Trichobilharzia regenti is a neuropathogenic parasitic flatworm of birds which also causes cercarial dermatitis in humans. The species was originally described in 1998 in the Czech Republic and afterwards it was detected also in other European countries, e.g. Denmark, Germany, France, Iceland, Poland, Switzerland, or Russia, and even in Iran. For its unique neurotropic behaviour in vertebrate hosts, the host-parasite interactions are extensively studied in terms of molecular biology, biochemistry and immunology.

<i>Schistosoma mansoni</i> Species of fluke

Schistosoma mansoni is a water-borne parasite of humans, and belongs to the group of blood flukes (Schistosoma). The adult lives in the blood vessels near the human intestine. It causes intestinal schistosomiasis. Clinical symptoms are caused by the eggs. As the leading cause of schistosomiasis in the world, it is the most prevalent parasite in humans. It is classified as a neglected tropical disease. As of 2021, the World Health Organization reports that 236.6 million people have schistosomiasis and most of it is due to S. mansoni. It is found in Africa, the Middle East, the Caribbean, Brazil, Venezuela and Suriname.

Swimmers itch Medical condition

Swimmer's itch, cercarial dermatitis or schistosome dermatitis is a short-term allergic immune reaction occurring in the skin of humans that have been infected by water-borne schistosomes, a type of flatworms. It is common in freshwater, brackish and marine habitats worldwide. Incidence may be on the rise, although this may also be attributed to better monitoring. Nevertheless, the condition has been regarded as an emerging infectious disease.

<i>Biomphalaria</i> Genus of gastropods

Biomphalaria is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies.

Liver fluke Group of liver parasites

Liver fluke is a collective name of a polyphyletic group of parasitic trematodes under the phylum Platyhelminthes. They are principally parasites of the liver of various mammals, including humans. Capable of moving along the blood circulation, they can occur also in bile ducts, gallbladder, and liver parenchyma. In these organs, they produce pathological lesions leading to parasitic diseases. They have complex life cycles requiring two or three different hosts, with free-living larval stages in water.

Schistosoma indicum is a species of digenetic trematode in the family Schistosomatidae. The parasite is widespread in domestic animals in India and other Asian countries.

<i>Biomphalaria glabrata</i> Species of mollusc

Biomphalaria glabrata is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.

<i>Catatropis johnstoni</i> Species of fluke

Catatropis johnstoni is a fluke from the United States. It was first described in 1956 by Martin, who had found cercariae released by the snail Cerithidea californica in southwestern California. When the cercaria were fed into chickens, they developed into mature worms; Martin speculated that the natural host was a waterbird. In 1970, a study of helminths of the marsh rice rat in a saltmarsh at Cedar Key, Florida, found flukes similar to C. johnstoni. The fluke was present in 30% of 110 examined rice rats, with the number of worms per rat varying from 1 to 500. Some Cerithidea scalariformis snails from this marsh also released cercariae similar to C. johnstoni from California. When introduced into chickens, marsh rice rats, Mongolian gerbils, golden hamsters, and house mice, these cercariae developed into infectious flukes. Bush and Kinsella, who reported on the result in 1972, regarded the Florida and California flukes as the same species, as there were only minor size differences between them. Because no marsh-inhabiting rodent occurs in both California and Florida, they agreed with Martin that the normal host of C. johnstoni was most likely a bird, perhaps a rail or shorebird. Nevertheless, the rate of infection in the rice rat is too high for it to be just an accidental host; perhaps C. johnstoni is restricted to saltmarshes but not host-specific.

<i>Indoplanorbis</i> Genus of gastropods

Indoplanorbis is a genus of air-breathing freshwater snail. Its only member species is Indoplanorbis exustus, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. The species is widely distributed across the tropics. It serves as an important intermediate host for several trematode parasites. The invasive nature and ecological tolerance of Indoplanorbis exustus add to its importance in veterinary and medical science.

<i>Schistosoma spindale</i> Species of fluke

Schistosoma spindale is a species of digenetic trematode in the family Schistosomatidae. It causes intestinal schistosomiasis in the ruminants.

<i>Bivitellobilharzia nairi</i>

Bivitellobilharzia nairi is a species of trematodes, part of the family Schistosomatidae. This is a fairly new identified endoparasite that was found in 1955 by Mudaliar and Ramanujachari, who first recorded the parasite in India. Researchers collected fecal samples of the Indian rhinoceros and were startled to find B. nairi eggs.

Schistosoma bovis is a two-host blood fluke, that causes intestinal schistosomiasis in ruminants in North Africa, Mediterranean Europe and the Middle East. S. bovis is mostly transmitted by Bulinus freshwater snail species. It is one of nine haematobium group species and exists in the same geographical areas as Schistosoma haematobium, with which it can hybridise. S. bovis-haematobium hybrids can infect humans, and have been reported in Senegal since 2009, and a 2013 outbreak in Corsica.

Heterobilharzia is a genus of trematodes in the family Schistosomatidae. The species Heterobilharzia Americana is a parasite of the Southeastern United States and typically found in raccoons. Species of this genus are responsible for Schistosoma in canines. Cercariae found in freshwater may also cause Swimmer's itch in humans.

References

  1. 1 2 3 Platt TR, Blair D, et al. 1991. Griphobilharzia amoena n. gen., n. sp. (Digenea: Schistosomatidae), a parasite of the freshwater crocodile Crocodylus johnstoni (Reptilia: Crocodylia) from Australia, with the erection of a new subfamily, Griphobilharziinae. Journal of Parasitology77:65–68.
  2. McLaren, D. J., Hockley, D. J. 1977. Blood flukes have a double outer membrane. Nature269: 147–149.
  3. Smith, J. W. 1972. The blood flukes (Digenea: Sanguinicolidae and Spirorchidae) of cold-blooded vertebrates and some comparison with the schistosomes. Helminthological Abstracts Series A41:161–204.
  4. Brant S.V., Loker E.S. 2005. Can Specialized Pathogens Colonize Distantly Related Hosts? Schistosome Evolution as a Case Study. PLoS Pathogens 1(3): e38. doi : 10.1371/journal.ppat.0010038 Figure 1.
  5. 1 2 3 Brant, S. V., and Loker, E. S. 2005. Can specialized pathogens colonize distantly related hosts? Schistosome evolution as a case study. Public Library of Science Pathogens1: 38.