A video of Vermiviatum covidum. A scale is shown at the end and is graduated in millimetres
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.[2][4]
Genera
Species in the subfamily Bipaliinae are grouped in the following genera:[4]
Several hammerhead flatworms have become invasive, the most famous being Bipalium kewense, now in many countries in all continents except the Antarctica. A 2022 study used occurrence records from online databases, including iNaturalist, 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.[6]
References
^Sluys, R.; Kawakatsu, M.; Riutort, M.; Baguñà, J. (2009). "A new higher classification of planarian flatworms (Platyhelminthes, Tricladida)". Journal of Natural History. 43 (29–30): 1763–1777. doi:10.1080/00222930902741669.
^ abWinsor, 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.
^ abSolà, E., Sluys, R., Riutort, M., Kawakatsu, M. (18 August 2023). "Molecular phylogenetics facilitates the first historical biogeographic analysis of the hammerhead worms (Platyhelminthes: Tricladida: Bipaliinae), with the description of twelve new species and two new genera". Zootaxa. 5335 (1): 1–77. doi:10.11646/zootaxa.5335.1.1. ISSN1175-5334.
