Lebertia algeriensis, Lundblad, 1942

Pešić, Vladimir, Zawal, Andrzej, Bankowska, Aleksandra, Araújo, Ricardo, Sługocki, Łukasz, Rewicz, Tomasz, Krakowiak, Maja, Michoński, Grzegorz, Girão, Dinis, Da Silva, Luis P., Órfão, Inês, Raposeiro, Pedro M., Ballini, Lorenzo, Stryjecki, Robert, Ekrem, Torbjørn & Ferreira, Sónia, 2025, Exploring the water mite fauna (Acari, Hydrachnidia) of the Madeira archipelago: DNA Barcoding reveals a remarkable species endemicity, Zootaxa 5621 (5), pp. 501-513 : 511

Lebertia algeriensis in Madeira —the first documented invasive species of water mites?

In his extensive work on Madeiran water mites, Lundblad (1942) lists only two species of the genus Lebertia , L. maderigena and L. madericola , inhabiting running waters on the island. During his field research in Madeira, Lundblad collected a total of 271 specimens, 92 from L. maderigena and 179 from L. madericola at 15 localities. This material, deposited in the Stockholm Natural History Museum, has recently been verified by García-Jiménez et al. (2017). The latter authors collected new material of Lebertia , which included only two abovementioned endemic species, at the three different localities during 2012 and 2013. Harry Smit (Pers. communication) collected water mites on Madeira in June 2006. There were 18 localities with Lebertia madericola and 2 with L. maderigena , but no L. algeriensis (H. Smit, unpublished data). In this study, in addition to the two previously known endemic species of the genus, we collected and barcoded one more species, L. algeriensis , which was not known to occur in Madeira until now. The latter species, with 92 new barcodes, is the most common Lebertia species in our material. Genetic data revealed that Madeiran specimens of L. algeriensis belong to the same BIN which also includes specimens from Greece and Slovakia.

Given that L. algeriensis (or any other species of Pilolebertia ) was not found during Lundblad’s and Smit’s intensive surveys of the water mite fauna of Madeira, it seems reasonable to assume that L. algeriensis colonized Madeira recently, within the last eighty years, or even the last 15 years. Our study revealed the occurrence of this species in different watersheds of Madeira, where it has since become common, suggesting the invasive potential of this species. Available data suggests that L. algeriensis may be the first species of water mite documented as potentially, if not invasive, non-indigenous in the freshwater ecosystems of Madeira.

Elucidating how this species arrived in the freshwater ecosystems of Madeira requires additional information on the distribution and ecology of this species, which is still scarce. It is possible that this species was accidentally introduced by natural vectors such as their insect hosts. The presence of L. algeriensis in geographically distant regions ( Greece, Slovakia, Madeira) suggests a broad distribution, potentially facilitated by anthropogenic or natural dispersal mechanisms. Given the relatively low diversity and high endemicity of Madeiran water mite fauna, we cannot exclude that the presence and spread of L. algeriensis over time could, if not already, lead to a decline in the richness and abundance of water mites in the invaded ecosystems. The presence of sequences of this species (and the corresponding BIN) in public DNA barcode libraries allows efficient monitoring of this species in Madeira’s watersheds, but also in other regions (which include a large geographical area from Greece and Slovakia to Madeira) where this species has already been detected. New genetic data could help in tracing the invasion pathways of this species and identifying the origin of the population(s) now present on the island.