Bipalium kewense
| Bipalium kewense | |
|---|---|
 | |
| Bipalium kewense | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Platyhelminthes |
| Class: | Rhabditophora |
| Order: | Tricladida |
| Suborder: | Continenticola |
| Family: | Geoplanidae |
| Subfamily: | Bipaliinae |
| Genus: | Bipalium |
| Species: | B. kewense |
| Binomial name | |
| Bipalium kewense Moseley, 1878 | |
| Synonyms | |
| |
Bipalium kewense is a species of large predatory land planarian with a cosmopolitan distribution.[1] It is sometimes referred to as a "hammerhead flatworm" due to its half-moon-shaped head, but this name is also used to refer to other species in the subfamily Bipaliinae.
Description
Bipalium kewense is a very long land planarian. The anterior end ("head") is expanded in a transversal semilunate shape and the body is the narrowest just behind the head, in a region called "neck". The dorsal color is light-brown with five black to grey longitudinal stripes that begin at the neck. The median and marginal stripes are narrow and black, very distinctly marked. The lateral stripes (between the median and marginal stripes) are usually grey, broad and with diffuse margins. The neck is usually marked by an incomplete black collar formed by the union of the marginal and lateral stripes. The head usually has a darker color than the background color of the dorsum. The ventral side is white and externally lined by two diffuse grey longitudinal lines.[1]
Distribution
Bipalium kewense is believed to be native to Southeast Asia, but currently is found worldwide. It was probably introduced by international plant trade, as it is frequently found associated to plant pots.[1][2][3]
Feeding habits
B. kewense is a known predator of earthworms. It immobilizes the prey using muscular movements and possibly toxins and then everts its pharynx, connecting it to the earthworm's body and beginning digestion. The digestion seems to be at least partially extracorporeal by means of a collagenolytic enzyme.[4]
Toxicity
Bipalium kewense is known to produce tetrodotoxin, a neurotoxin that results in paralysis. It is possible that the toxin aids the planarian in subduing its prey as well as in protecting it against predators.[5]
Reproduction
All species of Bipalium are hermaphroditic, but Bipalium kewense has rarely been observed using sexual reproduction as a primary means of reproduction.[6] Asexual fragmentation is the primary means of reproduction in B. kewense in temperate regions.[1] Although there is little evidence of sexual reproduction in these planarians, there have been several reported cases of egg capsules being discovered. The egg capsules discovered had several of the same characteristics of those of B. adventitium, including coloration and incubation period. The most recent egg capsule discovered hatched offspring that did not bear a complete resemblance to adults and were considerably larger in size to that of B. adventitum offspring.[6]
References
- 1 2 3 4 Winsor, L. (1983). "A revision of the cosmopolitan land planarian Bipalium kewense Moseley, 1878 (Turbellaria: Tricladida: Terricola)". Zoological Journal of the Linnean Society. 79 (1): 61–100. doi:10.1111/j.1096-3642.1983.tb01161.x. ISSN 0024-4082.
- ↑ Winsor, L.; Johns, P. M.; Barker, G. M. (2004) "Terrestrial planarians (Platyhelminthes: Tricladida: Terricola) predaceous on terrestrial gastropods." In: Barber, G. M. (ed.) Natural enemies of terrestrial molluscs, Wallingford, CABI, 227-278.
- ↑ Justine, Jean-Lou; Winsor, Leigh; Gey, Delphine; Gros, Pierre; Thévenot, Jessica (2014). "The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now.". PeerJ. 2: e297. doi:10.7717/peerj.297. PMC 3961122
. PMID 24688873. 
- ↑ Phillips, Julius; Desden, Marc. H. (1973). "A Collagenase in extracts of the invertebrate Bipalium kewense". Biochemical Journal. 133: 329–334. doi:10.1042/bj1330329. PMC 1177702. PMID 4353237.
- ↑ Dickens, Joseph Clifton; Stokes, Amber N.; Ducey, Peter K.; Neuman-Lee, Lorin; Hanifin, Charles T.; French, Susannah S.; Pfrender, Michael E.; Brodie, Edmund D.; Brodie Jr, Edmund D. (2014). "Confirmation and Distribution of Tetrodotoxin for the First Time in Terrestrial Invertebrates: Two Terrestrial Flatworm Species (Bipalium adventitium and Bipalium kewense)". PLoS ONE. 9 (6): e100718. doi:10.1371/journal.pone.0100718. ISSN 1932-6203.
- 1 2 Ducey, Peter K.; Cerqua, Jamie; West, Lori-Jeanne; Warner, Monica; Eberle, Mark E. (2006). "Rare egg capsule production in the invasive terrestrial planarian Bipalium kewense". The Southwestern Naturalist. 51 (2): 252–255. doi:10.1894/0038-4909(2006)51[252:RECPIT]2.0.CO;2. ISSN 0038-4909.