Bipalium kewense, Moseley, 1878 Moseley, 1878

Justine, Jean-Lou, Gastineau, Romain & Winsor, Leigh, 2024, Land flatworms (Tricladida: Geoplanidae) in France and French overseas territories: ten years of research, Zoologia (e 24004) 41, pp. 1-25 : 5-6

Bipalium kewense

Bipalium kewense ( Figs 8–10 ) is well known as a species that has invaded most tropical or subtropical regions of the world, particularly through plant transport ( Winsor 1983), probably including, in the early stages, “Ward’s Boxes” used to transport exotic plants ( Keogh 2020). For B. kewense , we have received two types of reports for mainland France: a few reports in greenhouses, which have no biogeographical value, and to our surprise numerous reports in open environments, within gardens. The citizen science reports spanned around 20 years, the most emblematic being from an individual who kept an old VHS tape showing the family being surprised by the presence of a large worm in their garden ( Justine et al. 2018b). Reports in gardens are restricted to a small coastal strip along the Mediterranean coast and to a wider area along the Atlantic coast that corresponds to the department of Pyrénées-Atlantiques ( Fig. 10 ). These zones correspond to the hottest regions of mainland France and, for the Pyrénées-Atlantiques, to a warm region but where summer is never completely dry. Citizen science accounts report that in order to escape the cold in winter, this species buries itself up to twenty centimeters deep in the soil. Outside of mainland France, B. kewense is also known from the French Caribbean (Guadeloupe, Martinique, and Saint Martin), French Guiana, Reunion Island, and French Polynesia ( Justine et al. 2018b), regions whose climate better corresponds to its area of origin in Southeast Asia than to mainland France. New records are regularly published from various tropical and semitropical countries ( Agnolin et al. 2019, Borge Medina and Nuñez Martinez 2021, de Luna et al. 2022, Morffe et al. 2016, Mori et al. 2023, RodrÍguez-Cabrera and Torres 2019).

Genetic studies on B. kewense showed that specimens collected on several continents had exactly the same cox1 sequence ( Justine et al. 2018b). This suggests that all the collected individuals, which reproduce asexually and have no sexual organs, are in fact a clone, or, in other words, that a single individual has invaded several continents. However, our studies were limited to a single gene. Bipalium kewense is also the first species for which we obtained a complete mito - genome ( Gastineau et al. 2019) and, as such, was the starting point for our genomic investigations on the Geoplanidae .

Figures

Figure 10. Map of occurrence of Bipalium kewense in mainland France including Corsica. Based on 110 observations in the Openobs database.

Figures 8–9. Bipalium kewense: (8) Alive, general morphology. Dorsal aspect of the planarian with a partial view of the ventral surface. (9) Predation on earthworm. The flatworm initiates here the process of ‘capping’ the anterior end of the earthworm. Photo by Pierre Gros, from Justine et al. (2018b).