Schmidtea polychroa

Schmidtea polychroa
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Platyhelminthes
Order:	Tricladida
Family:	Dugesiidae
Genus:	Schmidtea
Species:	S. polychroa
Binomial name
Schmidtea polychroa (Schmidt, 1861)
Synonyms
Dugesia (Schmidtea) polychroa(Schmidt, 1861) Dugesia polychroa(Schmidt, 1861) Euplanaria polychroa(Schmidt, 1861) Planaria polychroaSchmidt, 1861

Schmidtea polychroa is a species of freshwater flatworm, a dugesiid triclad that inhabits the shallow mesotrophic or eutrophic waters of rivers and lakes of Europe. It is also present in North America, where it has been introduced at least in the Saint Lawrence river system. ^{[1] [2]} It is an animal with a limited dispersion capability. ^[3]

Description

S. polychroa has a rounded head and a pointed back end with relatively no constriction. There are two eyes. While the color is generally brown, it can range from dark brown to black, and specimens of a black-green color and even with piebald-like patterns have been observed. ^[4]

Diet

Individuals of this species search for food actively. They feed mainly on small invertebrates, ^[5] and show a preference for oligochaetes and gastropods. ^[1] However, they can also feed on the carcasses of large animals, such as dead frogs. ^[6]

Reproduction

They are hermaphroditic. Schmidtea polychroa produces cocoons in water temperatures between 10 and 23 °C. ^[7]

References

1. Boddington, M. J.; Mettrick, D. F. (1974). "The distribution, abundance, feeding habits, and population biology of the immigrant triclad Dugesia polychroa (Platyhelminthes: Turbellaria) in Toronto Harbour, Canada". Journal of Animal Ecology. 43 (3): 681–699. Bibcode:1974JAnEc..43..681B. doi:10.2307/3531. JSTOR   3531.
2. Kenk, R. (1989). Revised list of the North American freshwater Planarians (Platyhelminthes. Smithsonian Contributions to Zoology 476, 1-10.
3. Pongratz, N.; Gerace, L.; Michiels, N. K. (2002). "Genetic differentiation within and between populations of a hermaphroditic freshwater planarian". Heredity. 89 (1): 64–69. Bibcode:2002Hered..89...64P. doi: 10.1038/sj.hdy.6800102 . PMID   12080371.
4. Schmidt, O. (1861). Uber Planaria torva Autorum. Z wiss Zool (in German). 11(1):92-94 via Biodiversity Heritage Library.
5. Calow, P.; Davidson, A. F.; Woollhead, A. S. (1981). "Life-cycle and feeding strategies of freshwater triclads: A synthesis". Journal of Zoology. 193 (2): 215–237. doi:10.1111/j.1469-7998.1981.tb03441.x.
6. Bonthron, James Douglas; Phillips, Neil; Goodman, Mark J. (2024). "European common frog Rana temporaria carcass scavenged by the planarian Schmidtea polychroa". The Herpetological Bulletin (170): 46. doi:10.33256/hb170.46.
7. Reynoldson, T. B.; Young, J. O.; Taylor, M. C. (1965). "The Effect of Temperature on the Life-Cycle of Four Species of Lake-Dwelling Triclads". Journal of Animal Ecology. 34 (1): 23–43. Bibcode:1965JAnEc..34...23R. doi:10.2307/2367. JSTOR   2367.