Dendrobaena, Eisen, 1874

Shekhovtsov, S. V, Rapoport, I. B., Leonov, P. A., Poluboyarova, T. V., Yurlova, G. V., Shipova, A. A., Vasiliev, G. V., Golovanova, E. V., Roohi Aminjan, A. & Latif, R., 2024, Phylogeny of Lumbricidae based on mitochondrial genomes with emphasis on the genus Dendrobaena, Organisms Diversity & Evolution 24 (4), pp. 477-487 : 481-482

The genus Dendrobaena

The majority of our specimens belonged to the genus Dendrobaena , which includes many endemic species found in the Caucasus ( Kvavadze, 1985; Pizl, 1984; Vsevolodova-Perel, 2003). The monophyly of Dendrobaena was contested: Csuzdi (1984) made a thorough revision of the genus and proposed four species groups: “ octaedra ,” “ schmidti ,” “ byblica ,” and “ veneta .” The conclusions of Csuzdi (1984) were based on the morphology of the male genital pores, the circulatory system, calciferous glands, and muscles. Molecular data appeared to corroborate the division of the genus into several groups. For example, on the phylogenetic reconstructions of Marchán et al. (2021a), representatives of the genus Dendrobaena were scattered throughout the trees, so Marchán et al. (2022) concluded that Dendrobaena formed “several unrelated genus-level clades.”

Other molecular studies yielded similar results. The majority of them identified a clade consisting of Dendrobaena , Healyella , Spermophorodrilus , and Fitzingeria ( Domínguez et al., 2015; Pérez-Losada et al., 2015; Csuzdi et al., 2017; Marchán et al., 2022). In these studies, D. byblica was also found to be outside the main Dendrobaena clade, as in the trees of Marchán et al. (2021a) and on our data (Fig. 1). Three of the aforementioned studies ( Domínguez et al., 2015; Pérez-Losada et al., 2015; Marchán et al., 2022) identified Dendrobaena as the sister group to Octolasion + Octodrilus . However, in our study, we found that O. tyrtaeum was more closely related to A. jassyensis rather than to Dendrobaena . We should note that the current analysis includes only one species of Octolasion and no representatives of Octodrilus .

Previous molecular studies included only a few representatives of Dendrobaena . Here, we added more specimens, and it turns out that all of the specimens except for D. byblica formed a clade. Previous papers also indicated that this taxon was not closely related to other Dendrobaena species ( Csuzdi et al., 2017; Domínguez et al., 2015; Latif et al., 2020; Marchán et al., 2022). However, it is important to note that D. byblica is a polymorphic species with multiple cryptic species and a complex taxonomic history ( Szederjesi et al., 2018a, 2018b).

Marchán et al. (2022) suggested that D. byblica might be better classified within the genus Omodeoia Kvavadze (1993) . Previously, Kvavadze (1993) discovered that certain species of the genus Dendrobaena possessed three-striatal genital setae, in contrast to the typical four-striatal structure found in the rest of the genus ( Kvavadze, 1993; Kvavadze et al., 2007). Based on this observation, he proposed the genus Omodeoia , with D. byblica designated as the type species. However, limited DNA data is currently available for other potential members of this genus.

Two early-branching species within Dendrobaena were D. octaedra and D. attemsi . Morphologically, D. attemsi is close to the Balkan species ( D. mahnerti , D. epirotica , D. pindonensis , and D. rhodopensis ) ( Rota, Erséus, 1997), but based on the position of the clitellum and tuberculae pubertatis, it is close to D. octaedra . Both species are epigeic. D. octaedra is a peregrine species. D. attemsi has a more limited range. D. octaedra is widespread, up to high latitudes in Eurasia and North America ( Cameron et al., 2008; Shekhovtsov et al., 2018; Tiunov et al., 2006), while D. attemsi is more common in southern Europe.