A list of the endemic earthworms of the Balkan Peninsula is presented. Comprehensive information on the ecology, distribution on the Balkan Peninsula and zoogeographical type of all endemics is given. The list comprises 90 species and subspecies, belonging to 11 genera of the family Lumbricidae. The largest number of the Balkan endemic earthworms belongs to a narrow range group (63.3%). Broad range endemic species take part with 36.7%. Our study shows that the degree of endemism on the Balkan Peninsula is extremely high (about 40%) suggesting an important process of autochthonous speciation on the Balkan Peninsula. This appearance is attributable to relative isolation of the mountains compared to the lowlands within the context of paleoenvironmental changes.

A checklist of the lumbricid earthworms in Serbia is presented. For the first time, comprehensive informations of all lumbricids in the country are given in order to establish the definitive list of known taxa from Serbia. The list underlines earthworm diversity and provides a general overview of their ecology, distribution in Serbia, and zoogeographical position. The complete list of earthworm taxa of Serbia comprises 74 species and subspecies of Lumbricidae, belonging to 15 genera. One third of earthworms in Serbia are endemics (26 taxa = 35.1%).

In the current paper we present an updated checklist of all the megadrile earthworms (Crassiclitellata: Annelida) in the world, and notes on the distribution of families worldwide. Biogeographic responses to geological phenomena including plate tectonics, as well as to past and present climate and habitat distributions, are the main factors determining the present distribution of earthworm families. A total of ca. 5,738 species/subspecies (5,406 species and 332 unique subspecies; i.e., not counting the nomino-typical subspecies) belonging to 23 families (including one non-crassiclitellate family: Moniligastridae) are currently recognized worldwide, of which three families (Tritogeniidae and Kazimierzidae from Southern Africa and Arecoidae, a new family from Brazil described herein), 35 genera and close to 1200 new taxa (including subspecies) were described in the 21st century. Nonetheless, the large number of still undescribed species will likely increase this value to well over 8,000 species. Ten families are monospecific and/or monogeneric and have a mostly restricted distribution. On the other hand, more than 87 widespread cosmopolitan species have been catalogued, some of them with important invasive potential, belonging mainly to families Lumbricidae, Acanthodrilidae, Benhamiidae, Megascolecidae, Rhinodrilidae and Ocnerodrilidae. Taxonomic housekeeping was performed for the preoccupied Rhinodrilidae genus Tairona Righi – herein substituted by Taironina nom. nov., and Guarani camaqua Rodríguez & Lima was reinstated and removed from synonymy with Criodrilus lacuum Hoffmeister, 1845, resulting in a wider definition of the Almidae family. Furthermore, Amynthas maximalis nom. nov. is proposed herein as a substitution name for the preoccupied name Amynthas maximus Qiu & Dong, 2019, and Arecoidae is proposed herein as a new monotypic family for the aquamegadrile species Areco reco Righi, Ayres & Bittencourt, 1978.

Allolobophora (sensu lato) is one of the most controversial genera in the taxonomy of Lumbricidae. Due to its poor definition, this genus is plagued by extensive taxonomic confusion, and its generic composition and internal relationships have remained uncertain, especially in species of the Balkan Peninsula. In this study, we have combined the study of morphological data and molecular phylogenetics based on five genetic markers, regions of the nuclear 28S rRNA and mitochondrial 16S rRNA, 12S rRNA, NADH dehydrogenase (ND1) and cytochrome oxidase C subunit 1 (COI), to delimit the taxonomic status of five controversial Balkanic endemic species, Allolobophora (s.l.) dofleini, Allolobophora (s.l.) serbica, Allolobophora (s.l.) strumicae, Allolobophora (s.l.) paratuleskovi and Allolobophora (s.l.) treskavicensis, sampled in the Kopaonik Mountain. Phylogenetic analyses based on our sampling of these five species recovered a well-supported clade containing the species Allolobophora (s.l.) robusta, Allolobophora (s.l.) mehadiensis mehadiensis, Allolobophora (s.l.) sturanyi dacica, Cernosvitovia rebeli and Cernosvitovia dudichi. Based on these results and previous evidence, the aforementioned Balkanic species are transferred to a redefined Cernosvitovia. We further present a revised list of all species currently included in Cernosvitovia., which includes now 21 species and subspecies taxa, 13 of them newly combined here. Serbiona Mršić & Šapkarev, 1988 is considered a junior synonym of Cernosvitovia Omodeo, 1956.

This paper presents the first list of earthworm fauna of the Kopaonik National Park, a total of 16 taxa, belonging to eight genera of the family Lumbricidae. The genera with the largest number of the registered taxa are Dendrobaena and Lumbricus, while the genera Aporrectodea, Bimastos, Eisenia, Eiseniella, Octodrilus and Octolasion are represented by one species each. Also, the review of zoogeographical types and ecological categories of registered species are presented. Half of the species are peregrine, while the rest are autochthonous. Regarding ecological categories, anecic (2) and endogeic (4) species are more sensitive to high mountain environmental conditions than epigeic (12) species, which are more adapted to such conditions. Overall, our results highlight how little was previously known about the earthworm fauna in this area and emphasize the need for further collecting to better understand the hidden earthworm diversity in Kopaonik NP.