Misplaced Pages

Microphallus turgidus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Trematoda
Order:	Plagiorchiida
Family:	Microphallidae
Genus:	Microphallus
Species:	M. turgidus
Binomial name
Microphallus turgidus (Leigh, 1958)
Synonyms
Carneophallus turgidus

Microphallus turgidus is a widespread and locally common flatworm parasite in New Zealand lakes and streams. Multilocus allozyme genotype data show that Microphallus turgidus is a single outbred species with high levels of gene flow among South Island populations. Microphallus turgidus is commonly found in the abdominal muscles of grass shrimp.

Life cycle

Microphallus turgidus exclusively uses the snail Potamopyrgus antipodarum as the first intermediate host, a shrimp as the secondary intermediate host, and the final hosts are typically waterfowl. Embryonated Microphallus turgidus eggs are ingested from sediment and hatch in the snail's gut, penetrate the intestine, and migrate to the gonads and digestive gland. Following successful establishment, the parasite then undergoes asexual reproduction, replacing much of the host's reproductive tissue and digestive gland, which results in complete sterilization of the snail. The first visible parasite developmental stages (blastocercariae) are detectable after approximately 75 days post-exposure and metacercariae are common by 90 days post-exposure at 16 °C in the lab. The life cycle continues through a secondary intermediate host, such as the glass shrimp Palaemonetes pugio, and is completed when the shrimp infected by the metacercariae are consumed by waterfowl or mammals.

Host

Microphallus turgidus are more common in wild animals that live in salt marshes and are considered as definite host. The first intermediate host is the hydrobiid snail, on its immature form called a cercaria, it develops into snail. The most common is the second intermediate hosts, grass shrimp, Palaemonetes pugio. Metacercariae of the parasite usually encyst in grass shrimp abdominal muscle, and though adult P. pugio average only 2.9 cm in length, a shrimp can be infected with more than 100 parasites.

Symptoms / effects

Numerous reports of changes in the host behavior after the parasitic infection influenced the host-parasite survival, host predation, and parasite transmission. Parasite induced behavior changes include hyperactivity, sluggishness, fatigue, disorientation, altered habitat selection, and reduced predator avoidance. In fact, it is rare are to find a locality where the grass shrimp Palaemonetes pugio is not infected.

At certain shrimp collection sites, near all specimens of P. pugio are infected, some with more than 100 parasites. The intensity of infection varies from one locality to another and may be due, at least partially, to geographic differences in salinity. Heavily infected shrimp are more likely to be eaten by a predator than uninfected shrimp, have lower swimming stamina, and spend more time swimming and less time motionless in the presence of a predator. Thus, M. turgidus may increase the predation of P. pugio in the wild.

References

1. Microphallus turgidus on uniprot.org/taxonomy
2. Leigh, WH (1958), "Carneophallus turgidus sp. nov. (trematoda: Microphallidae) from the raccoon, Procyon lotor, in South Florida", The Journal of Parasitology, 44 (1): 100–2, doi:10.2307/3274837, JSTOR 3274837, PMID 13526074
3. Osnas, EE; Lively, CM (2005), "Immune response to sympatric and allopatric parasites in a snail-trematode interaction", Frontiers in Zoology, 2: 8, doi:10.1186/1742-9994-2-8, PMC 1177977, PMID 15927050
4. Pung, Oscar J.; Burger, Ashley R.; Walker, Michael F.; Barfield, Whitney L.; Lancaster, Micah H.; Jarrous, Christina E. (2009). "In vitro Cultivation of Microphallus turgidus (Trematoda: Microphallidae) from Metacercaria to Ovigerous Adult with Continuation of the Life Cycle in the Laboratory". Journal of Parasitology. 95 (4): 913–919. doi:10.1645/ge-1970.1. JSTOR 27735680. PMID 20049996. S2CID 207250475.
5. "Taxonomy and Life Histories of Two North American Species of "Carneophallus" (=Microphallus) (Digenea: Microphallidae)", Proceedings of the Helminth-thological Society of Washington, 50, University of Nebraska: 170–174, 1983, OCLC 750081565
6. Pung, OJ; Khan, RN; Vives, SP; Walker, CB (2002), "Prevalence, geographic distribution, and fitness effects of Microphallus turgidus (trematoda: Microphallidae) in grass shrimp (Palaemonetes spp.) from coastal Georgia", The Journal of Parasitology, 88 (1): 89–92, doi:10.1645/0022-3395(2002)088[0089:PGDAFE]2.0.CO;2, PMID 12053986, S2CID 22942015
7. Moore, Janice (2002), Parasites and the behavior of animals, Oxford series in ecology and evolution., Oxford, ISBN 978-0-19-514653-0
8. Flowers, Melody A; Pung, Oscar J (2004), Population genetics analysis of the grass shrimp Palaemonetes pugio using single strand conformation polymorphism, Georgia Southern University, OCLC 58396576
9. Kunz, Alyssa K; Pung, Oscar J (2004), "Effects of Microphallus turgidus (Trematoda: Microphallidae) on the Predation, Behavior, and Swimming Stamina of the Grass Shrimp Palaemonetes pugio", The Journal of Parasitology, 90 (3): 441–445, doi:10.1645/GE-183R, PMID 15270083, S2CID 10552028

• Animals described in 1958
• Plagiorchiida
• Parasites of molluscs
• Parasites of birds