Australiformis

Last updated

Contents

Australiformis
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Acanthocephala
Class: Archiacanthocephala
Order: Moniliformida
Family: Moniliformidae
Genus: Australiformis
Schmidt and Edmonds, 1989 [1]
Species:
A. semoni
Binomial name
Australiformis semoni
(Linstow, 1898) [1]
Synonyms
  • Echinorhynchus semoniLinstow, 1898
  • Gigantorhynchus semoni(Porta, 1908)
  • Prosthenorchis semoni(Travassos, 1917)
  • Moniliformis semoni(Johnston and Edmonds, 1952)

Australiformis is a monotypic genus of acanthocephalans (thorny-headed or spiny-headed parasitic worms) containing a single species, Australiformis semoni, that infests marsupials in Australia and New Guinea. Its body consists of a proboscis armed with hooks which it uses to pierce and hold the gut wall of its host, and a long trunk. This genus resembles species in the genus Moniliformis but is characterized by a lack of spiral muscles in the outer wall of the proboscis receptacle. The proboscis is armed with 12 rows of 13 to 15 hooks which are used to attach themselves to the small or large intestines of the host. The female worms range from 95 to 197 millimetres (3.7 to 7.8 in) long, virtually all of which is the trunk, and 1.75 to 3.5 millimetres (0.069 to 0.138 in) wide. There is pronounced sexual dimorphism in this species as females are around twice the size of the males whose trunks range from 46 to 80 millimetres (1.8 to 3.1 in) long and 2 millimetres (0.079 in) wide. Infestation by A. semoni may cause debilitating inflammation of the stomach (gastritis) with granulomatous ulcers.

Taxonomy

The taxonomic history of A. semoni is complex. It was originally named Echinorhynchus semoni by Linstow in 1898, [2] and then moved to Gigantorhynchus by Porta in 1908 [3] and Johnston in 1909, later moved to Prosthenorchis by Travassos in 1917, [4] then renamed Moniliformis semoni by Johnston and Edmonds in 1952 [5] before taking the present name and genus by Schmidt and Edmonds in 1989. [6] [1] The genus is monotypic, the only species, Australiformis semoni(Linstow, 1898) [lower-alpha 1] , being necessarily the type species. [7] Linstow named the species semoni after the German zoologist who discovered it, Richard Semon. [2]

The morphological traits of a simple, double-walled proboscis receptacle, eight cement glands (which are used to temporarily close the posterior end of the female after copulation) each with a giant nucleus, the brain at the posterior end of proboscis receptacle, and dorsal and ventral lacunar canals place this genus confidently in the order Moniliformida. The genus AustraliformisSchmidt and Edmonds, 1989 was created for Moniliformis semoni as this species differed from other species in Moniliformis and the other genera of the family Moniliformidae, Promoniliformis , because it lacked spiral muscles in the outer wall of the proboscis receptacle. The parasitizing of marsupials is also a unique trait of this genus among Acanthocephala. [1] The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on Australiformis that would confirm its position as a unique genus in the family Moniliformidae. [8]

Archiacanthocephala
Archiacanthocephala
Phylogenetic reconstruction for select species in the class Archiacanthocephala based on a 28S rRNA gene comparison from Gomes et. al (2019) and a 18S rDNA gene comparison from Amin et al. (2020). [9] [10] Unlike the other species shown, no genetic testing has been conducted on Australiformis semoni to confirm this classification which is inferred based on morphological traits. [1]

Description

Anatomical measurements of A. semoni
Measurements [1] Female (mm)Male (mm)
Length of proboscis0.640–0.8000.600–0.840
Width of proboscis0.280–0.3200.200–0.288
Length of proboscis receptacle1.2–1.581.0–1.7
Width of proboscis receptacle0.3–0.480.32–0.36
Length of neck0.225–0.2400.150–0.240
Width of neck at base0.200–0.2700.200–0.270
Length of trunk95–19746–80
Width of trunk1.75–3.52
Length of lemnisci25–2720–25
Size of anterior testis2.7–3.2 x 0.75–1.0
Size of posterior testis2.5–3.2 x 0.75–1.0
Size of cement glands0.64–1.2 x 0.44–0.72
Size of Saefftigen's pouch1.28 x 0.48–0.64
Size of eggs0.080–0.086 x 0.035–0.044
Distance from the uterine bell [lower-alpha 2] to genital pore1.95–2.2

A. semoni consists of a proboscis covered in hooks, a proboscis receptacle, and a long trunk. There is pronounced sexual dimorphism in this species; the females are around twice as long as the males (up to approximately 20 centimetres (7.9 in) in females and 8 centimetres (3.1 in) in males). The proboscis is long and swollen at the anterior end and tapers rapidly to a narrow base. The proboscis is armed with 12 rows of 13 to 15 hooks. The first three to four hooks in each row are large, aligned in straight rows, and have bifid roots whereas the other 10 to 12 posterior hooks are small rootless spines arranged in spirals down the proboscis. The first hook of each row is 40 to 56 micrometres (0.0016 to 0.0022 in) long, the second is 50 to 60 micrometres (0.0020 to 0.0024 in) long, the third is 42 to 50 micrometres (0.0017 to 0.0020 in) long, the fourth is 42 to 54 micrometres (0.0017 to 0.0021 in) long and the remaining spines are 30 to 60 micrometres (0.0012 to 0.0024 in) long. At the base of the proboscis is a double-walled proboscis receptacle with a smooth outer wall, lacking spirally arranged muscle fibers, and a large space between the walls. The brain is located near the posterior end of the proboscis receptacle with retinacula (a band of thickened deep fascia around tendons that holds them in place) piercing the proboscis receptacle wall laterally. Proboscis retractor muscles pierce the posterior end of the proboscis receptacle. [1]

The trunk is not pseudosegmented, is very thin at the anterior end and thickest at the posterior end averaging only a few millimeters in width. The main longitudinal lacunar canals are dorsal and ventral, with the dorsal canal being conspicuous and the ventral canal being very narrow. The transverse commissural canals are evenly spaced and connect to the main longitudinal canals. The lemnisci (bundles of sensory nerve fibers) are long, slender, twisted, and coiled in the body cavity (not attached distally to the body wall), and contain 10 to 15 giant nuclei each. They extend between one quarter to one third the length of the body. [1]

The eggs are oval with three apparent membranes. The outer membrane is thick with the exception of the anterior end where it is thin. The outer membrane is often indented and the posterior end is usually covered in small dots on the outer surface with a knob on the inner surface. The second membrane is very thin and the third membrane is thick. The males have a sensory pore on each side of the neck. Males have eight oval cement glands, each with a single giant nucleus, and possess a Saefftigen's pouch just behind the testes. [1] The testes are oval in tandem and found near the posterior end of the trunk. The genital pore is located at the terminal end of the trunk in both sexes. [1]

Distribution

The distribution of A. semoni is determined by that of its hosts. A. semoni has been found in several states of Australia, including Queensland, New South Wales, and Tasmania. This parasite has also been found in Boroko, Papua New Guinea. The type locality is the Upper Burnett River region in south-eastern Queensland. [1]

Hosts

Life cycle of Acanthocephala. Acanthocephala LifeCycle lg.jpg
Life cycle of Acanthocephala.

The life cycle of an acanthocephalan consists of three stages beginning when an infective acanthor (development of an egg) is released from the intestines of the definitive host and then ingested by an arthropod, the intermediate host. Although the intermediate hosts of Australiformis are not known, without exception for the order Moniliformida, this intermediate host is an insect. When the acanthor molts, the second stage called the acanthella begins. This stage involves penetrating the wall of the mesenteron or the intestine of the intermediate host and growing. The final stage is the infective cystacanth which is the larval or juvenile state of an Acanthocephalan, differing from the adult only in size and stage of sexual development. The cystacanths within the intermediate hosts are consumed by the definitive host, usually attaching to the walls of the intestines, and as adults they reproduce sexually in the intestines. The acanthor are passed in the feces of the definitive host and the cycle repeats. There are no known paratenic hosts (hosts where parasites infest but do not undergo larval development or sexual reproduction) for Australiformis. [13]

A. semoni parasitizes Australian and New Guinean marsupials including the type host, southern brown bandicoot (Isoodon obesulus) and related species such as the northern brown bandicoot (Isoodon macrourus), long-nosed bandicoot (Perameles nasuta), striped bandicoot (Perameles gunnii), common echymipera (Echymipera kalubu), and brush-tailed phascogale (Phascogale tapoatafa). A. semoni infests these hosts by using hooks on their proboscis to pierce and hold the wall of the small and large intestines. [1] A. semoni has also been found with the anterior end embedded in the mucosa of the stomach in the striped bandicoot. This infestation, which all observed cases contained 5 or fewer individual worms, may cause debilitating ulcerative granulomatous gastritis, a form of gastritis (inflammation of the stomach) characterised by ulcers and granuloma (an aggregation of macrophages that forms in response to chronic inflammation). [14] Juvenile worms were found in the accidental host (an organism that generally does not allow transmission to the definitive host) brown antechinus (Antechinus stuartii). [1] There are no reported cases of A. semoni infesting humans in the English language medical literature. [12]

Notes

  1. ↑ A binomial authority in parentheses indicates that the species was originally described in a genus other than Australiformis.
  2. ↑ a funnel like opening continuous with the uterus.
  3. ↑ There are no known aberrant human infections for A. semoni species. [12]

Related Research Articles

Apororhynchus is a genus of small parasitic spiny-headed worms. It is the only genus in the family Apororhynchidae, which in turn is the only member of the order Apororhynchida. A lack of features commonly found in the phylum Acanthocephala suggests an evolutionary branching from the other three orders of class Archiacanthocephala; however no genetic analysis has been completed to determine the evolutionary relationship between species. The distinguishing features of this order among archiacanthocephalans is a highly enlarged proboscis which contain small hooks. The musculature around the proboscis is also structured differently in this order. This genus contains six species that are distributed globally, being collected sporadically in Hawaii, Europe, North America, South America, and Asia. These worms exclusively parasitize birds by attaching themselves around the cloaca using their hook-covered proboscis. The bird hosts are of different orders, including owls, waders, and passerines. Infestation by an Apororhynchus species may cause enteritis and anemia.

<span class="mw-page-title-main">Giganthorhynchidae</span> Order of thorny-headed worms

Gigantorhynchida is an order containing a single family, Gigantorhynchidae of Acanthocephala that parasitize vertebrates by attaching themselves to the intestinal wall of their host. There are over 60 species classified into three genera in GigantorhynchidaGigantorhynchus, Intraproboscis, and Mediorhynchus.

<i>Gigantorhynchus</i> Genus of parasitic worms

Gigantorhynchus is a genus of Acanthocephala that parasitize marsupials, anteaters, and possibly baboons by attaching themselves to the intestines using their hook-covered proboscis. Their life cycle includes an egg stage found in host feces, a cystacanth (larval) stage in an intermediate host such as termites, and an adult stage where cystacanths mature in the intestines of the host. This genus is characterized by a cylindrical proboscis with a crown of robust hooks at the apex followed by numerous small hooks on the rest of the proboscis, a long body with pseudosegmentation, filiform lemnisci, and ellipsoid testes. The largest known specimen is the female G. ortizi with a length of around 240 millimetres (9.4 in) and a width of 2 millimetres (0.08 in). Genetic analysis on one species of Gigantorhynchus places it with the related genus Mediorhynchus in the family Gigantorhynchidae. Six species in this genus are distributed across Central and South America and possibly Zimbabwe. Infestation by a Gigantorhynchus species may cause partial obstructions of the intestines, severe lesions of the intestinal wall, and may lead to death.

Mediorhynchus is a genus of small parasitic spiny-headed worms. Phylogenetic analysis has been conducted on two known species of Mediorhynchus and confirmed the placement along with the related genus Gigantorhynchus in the family Gigantorhynchida. The distinguishing features of this order among archiacanthocephalans is a divided proboscis. This genus contains fifty-eight species that are distributed globally. These worms exclusively parasitize birds by attaching themselves around the cloaca using their hook-covered proboscis. The bird hosts are of different orders.

<span class="mw-page-title-main">Moniliformidae</span> Family of worms

Moniliformidae is a family of parasitic spiny-headed worms. It is the only family in the Moniliformida order and contains three genera: Australiformis containing a single species, Moniliformis containing eighteen species and Promoniliformis containing a single species. Genetic analysis have determined that the clade is monophyletic despite being distributed globally. These worms primarily parasitize mammals, including humans in the case of Moniliformis moniliformis, and occasionally birds by attaching themselves into the intestinal wall using their hook-covered proboscis. The intermediate hosts are mostly cockroaches. The distinguishing features of this order among archiacanthocephalans is the presence of a cylindrical proboscis with long rows of hooks with posteriorly directed roots and proboscis retractor muscles that pierce both the posterior and ventral end or just posterior end of the receptacle. Infestation with Monoliformida species can cause moniliformiasis, an intestinal condition characterized as causing lesions, intestinal distension, perforated ulcers, enteritis, gastritis, crypt hypertrophy, goblet cell hyperplasia, and blockages.

<i>Moniliformis</i> Genus of worms

Moniliformis is a genus of parasitic worms in the Acanthocephala phylum.

Promoniliformis is a monotypic genus of acanthocephalans containing a single species, Promoniliformis ovocristatus, that infests tenrecs in Madagascar. The genus PromoniliformisDollfus and Golvan, 1963 is characterized by possessing two distinct kinds of proboscis hooks. There is only one species in this genus.

<span class="mw-page-title-main">Oligacanthorhynchidae</span> Order of thorny-headed worms

Oligacanthorhynchida is an order containing a single parasitic worm family, Oligacanthorhynchidae, that attach themselves to the intestinal wall of terrestrial vertebrates.

Dendronucleata is a genus of small parasitic spiny-headed worms. It is the only genus in the family Dendronucleatidae. This genus contains three species that are distributed globally, being collected in North America and Asia. The distinguishing features of this genus among Archiacanthocephalans is the presence of randomly distributed dendritically branched giant hypodermic nuclei. Dendronucleata parasitize freshwater fish and a salamander by attaching themselves in the intestines using their hook covered proboscis and adhesives secreted from cement glands.

<i>Moniliformis moniliformis</i> Species of thorny-headed worm

Moniliformis moniliformis is a parasite of the Acanthocephala phylum in the family Moniliformidae. The adult worms are usually found in intestines of rodents or carnivores such as cats and dogs. The species can also infest humans, though this is rare.

<i>Pachysentis</i> Genus of worms

Pachysentis is a genus in Acanthocephala that parasitize primates and carnivorans. They are distributed across Africa, the Middle East, and the Americas. Pachysentis species attach themselves to the inner lining of the gastrointestinal tract of their hosts using their hook-covered proboscis. Their life cycle includes an egg stage found in host feces, a cystacanth (larval) stage in an intermediate host such as the Egyptian cobra, and an adult stage where cystacanths mature in the intestines of the host. This genus appears identical to the closely related Oncicola apart from a greater number of hooks on the proboscis. There are eleven species assigned to this genus, although P. septemserialis is of uncertain taxonomic status. The female worms range from 12 millimetres (0.47 in) long and 1.6 millimetres (0.063 in) wide in P. lauroi to 50 millimetres (2.0 in) long and 4 millimetres (0.16 in) wide in P. dollfusi. Virtually all of the length is the trunk, with a short proboscis. There is pronounced sexual dimorphism in this species as females are around twice the size of the males.

Oligacanthorhynchus is a genus of parasitic worms belonging to the family Oligacanthorhynchidae.

Atactorhynchus is a genus in Acanthocephala which contains two species, A. verecundus and A. duranguensis.

Tanaorhamphus is a monotypic genus of acanthocephalans containing a single species, Tanaorhamphus longirostris, that infests animals.

Machadosentis is a monotypic genus of acanthocephalans containing a single species, Machadosentis travassosi, that infests animals.

Pararaosentis is a monotypic genus of acanthocephalans containing a single species, Pararaosentis golvani.

Raosentis is a genus of Acanthocephala that parasitize the intestine of fish.

Triaspiron is a monotypic genus of acanthocephalans containing a single species, Triaspiron aphanii.

Caballerorhynchus is a monotypic genus of acanthocephalans containing a single species, Caballerorhynchus lamothei, that infests animals.

Intraproboscis is a monotypic genus of acanthocephalans that infest African black-bellied pangolin in the Central African Republic. Its body consists of a proboscis armed with hooks which it uses to pierce and hold the gut wall of its host, and a long trunk. It contains a single species, Intraproboscis sanghae. This genus resembles species in the genus Mediorhynchus but is characterized by infesting a mammal instead of birds, and having a simple proboscis receptacle that is completely suspended within the proboscis, the passage of the retractor muscles through the receptacle into the body cavity posteriorly, absence of neck, presence of a parareceptacle structure, and a uterine vesicle. The proboscis is armed with 34–36 rows of 6 to 7 hooks anteriorly and 15–17 spinelike hooks posteriorly which are used to attach themselves to the intestines of the host. The female worms are up to 180 millimetres long, virtually all of which is the trunk, and 2 millimetres wide.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 Schmidt, G.D.; Edmonds, S.J. (1989). "Australiformis semoni (Linstow, 1898) n. gen., n. comb. (Acanthocephala: Moniliformidae) from marsupials of Australia and New Guinea". The Journal of Parasitology. 75 (2): 215–7. doi:10.2307/3282769. JSTOR   3282769. PMID   2926590.
  2. 1 2 von Linstow, O.F.B. (1898). "Nemathelminthen von Herrn Richard Semon in Australien gesammelt". Denkschriften der Medizinisch-Naturwissenschaftlichen Gesellschaft zu Jena (in German). 8: 471–472 . Retrieved 23 March 2020.
  3. ↑ Porta, A. (1908). "Gli acantocefali dei mammiferi. Noto preventiva". Archives de parasitologie. 12 (2): 268–282.
  4. ↑ Travassos, L. (1917). "Contribuigoes para o conhecimento da fauna helmintolojica brazileira. VI. Revisao dos acantocefalos brazileiros. Parte l. Fam. Gigantorhynchidae Hamann, 1892". Memórias do Instituto Oswaldo Cruz (in Portuguese). 9: 5–62. doi: 10.1590/S0074-02761917000100001 .
  5. ↑ Johnston, T.H.; Edmonds, S.J. (1952). "Australian Acanthocephala No. 9". Transactions of the Royal Society of South Australia. 75: 16–21. Archived from the original on 21 March 2023. Retrieved 21 March 2023.
  6. ↑ "Moniliformida Schmidt, 1972". Integrated Taxonomic Information System (ITIS). 23 November 2019. Archived from the original on 3 May 2023. Retrieved 30 January 2020.
  7. ↑ Amin, O.M. (19 September 2013). "Classification of the Acanthocephala". Folia Parasitologica. 60 (4): 273–305. doi: 10.14411/fp.2013.031 . PMID   24261131.
  8. ↑ Schoch, Conrad L; Ciufo, Stacy; Domrachev, Mikhail; Hotton, Carol L; Kannan, Sivakumar; Khovanskaya, Rogneda; Leipe, Detlef; Mcveigh, Richard; O’Neill, Kathleen; Robbertse, Barbara; Sharma, Shobha; Soussov, Vladimir; Sullivan, John P; Sun, Lu; Turner, Seán; Karsch-Mizrachi, Ilene (2020). "NCBI Taxonomy: a comprehensive update on curation, resources and tools". Taxonomy Browser. NCBI. Retrieved 1 April 2024.
  9. ↑ Nascimento Gomes, A. P.; Cesário, C. S.; Olifiers, N.; de Cassia Bianchi, R.; Maldonado, A.; Vilela, R. do V. (December 2019). "New morphological and genetic data of Gigantorhynchus echinodiscus (Diesing, 1851) (Acanthocephala: Archiacanthocephala) in the giant anteater Myrmecophaga tridactyla Linnaeus, 1758 (Pilosa: Myrmecophagidae)". International Journal for Parasitology: Parasites and Wildlife. 10: 281–288. doi: 10.1016/j.ijppaw.2019.09.008 . PMC   6906829 . PMID   31867208.
  10. ↑ Amin, O.M.; Sharifdini, M.; Heckmann, R.A.; Zarean, M. (2020). "New perspectives on Nephridiacanthus major (Acanthocephala: Oligacanthorhynchidae) collected from hedgehogs in Iran". Journal of Helminthology. 94: e133. doi:10.1017/S0022149X20000073. PMID   32114988. S2CID   211725160.
  11. ↑ CDC’s Division of Parasitic Diseases and Malaria (11 April 2019). "Acanthocephaliasis". www.cdc.gov. Center for Disease Control. Archived from the original on 8 June 2023. Retrieved 17 July 2023.
  12. 1 2 Mathison, BA; et al. (2021). "Human Acanthocephaliasis: a Thorn in the Side of Parasite Diagnostics". J Clin Microbiol. 59 (11): e02691-20. doi:10.1128/JCM.02691-20. PMC   8525584 . PMID   34076470.
  13. ↑ Schmidt, G.D. (1985). "Development and life cycles". In Crompton, D.W.T.; Nickol, B.B. (eds.). Biology of the Acanthocephala (PDF). Cambridge: Cambridge Univ. Press. pp. 273–305. Archived (PDF) from the original on 22 July 2023. Retrieved 16 July 2023.
  14. ↑ Lenhaus, C.; Obendorf, D.; Wright, F.H. (1990). "Veterinary aspects of Perameles gunnii biology with special reference to species conservation". In Clark, T.W.; Seebeck, J.H. (eds.). Management and conservation of small populations. Brookfield, Illinois: Chicago Zoological Society. pp. 89–108. ISBN   0-913934-16-X . Retrieved 23 March 2020.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.