Bipaliinae is a subfamily of

land planarians Geoplanidae is a family of flatworms known commonly as land planarians or land flatworms. These flatworms are mainly predators of other invertebrates, which they hunt, attack and capture using physical force and the adhesive and digestive proper ...

found mainly in

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

, the

Indian subcontinent The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...

and

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

, although some species have been introduced worldwide.

Description

The subfamily Bipaliinae is characterized by having a semilunar head that gives them the common name "hammerhead worms". The head has peripheral sensory pits on the ventral side and small peripheral eyes on the dorsal side.Winsor, L.; Johns, P. M.; Barker, G. M. (2004). Terrestrial planarians (Platyhelminthes: Turbellaria: Tricladida: Continenticola) predaceous on terrestrial gastropods. ''In'': Barker, G. (ed.), ''Natural Enemies of Terrestrial Molluscs'', pp. 227-278.

Genera

Species in the subfamily Bipaliinae are grouped in the following genera: *'' Bipalium'' *'' Humbertium'' *'' Novibipalium'' *'' Umbotectum'' *'' Vermiviatum'' *'' Diversibipalium''

Bipaliin as invasive species

Several hammerhead flatworms have become invasive, the most famous being ''

Bipalium kewense ''Bipalium kewense'', also known as the shovel-headed garden worm, is a species of large predatory land planarian with a cosmopolitan distribution. It is sometimes referred to as a "hammerhead flatworm" due to its half-moon-shaped head, but this ...

'', now in many countries in all continents except the Antarctica. A 2022 study used occurrence records from online databases, including

iNaturalist iNaturalist is an American 501(c)(3) nonprofit social network of naturalists, citizen scientists, and biologists built on the concept of mapping and sharing observations of biodiversity across the globe. iNaturalist may be accessed via its web ...

, and climatic and soil variable to model the potential distribution of five species of hammerhead flatworms, namely '' B. kewense'', '' B. adventitium'', '' B. pennsylvaanicum'', '' B. vagum'', and '' Diversibipalium multilineatum''. It was found that the five species could invade Southeast Asia, New Zealand, Eastern Australian, a part of South America, eastern USA, western Europe and central Africa.

References

{{Taxonbar, from=Q18378622 Geoplanidae Articles containing video clips