Review of cavernicolous scorpions in the Balkans

 

Cavernicolous scorpions are fascinating with their choice of habitat and in some cases morphological adaptions. This group of scorpions are usually divided into four categories: Accidentals, trogloxenes, troglophiles, and troglobites. The categories are explained in the introduction of the article mentioned below. It is the two latter categories that have caves as their main habitats, but not all of the scorpions in these groups have troglomorphic traits (e.g. reduced eyes, reduced pigmentation etc.). They who do are true troglobites.

Javier Blasco-Aróstegui and Lorenzo Prendini have recently published a review of cavernicolous scorpions in the Balkans. They have classified the known cavernicolous species into the categories mention above, presented a redescription of the only real troglobitic species, Euscorpius studentium Karaman, 2020, and provided a identification key for the to the identification of cavernicolous scorpions occurring in the Dinaric Karst area.

Abstract:
Cavernicolous scorpions are difficult to collect and study due to their often inaccessible habitats. Some have evolved unique morphological adaptations, known as troglomorphies, including reduced sclerotization and pigmentation, reduction and/or loss of eyes, attenuation and elongation of the appendages, which assist them to thrive in dark, humid and low-energy input environments. Cavernicolous scorpions are classified into accidentals, trogloxenes, troglophiles, and troglobites. The Balkans, and particularly the Dinaric Karst region, host a diverse cave-adapted fauna, including scorpions. Despite an 1895 report of a blind scorpion from Bosnia and Herzegovina, the first truly troglobitic European scorpion, Euscorpius studentium Karaman, 2020, was only described a few years ago, based on two immature specimens. In the present contribution, this unique species is redescribed based on the first adult specimens; the ecological classification of all currently known cavernicolous Euscorpiidae Laurie, 1896, is updated; a key to the identification of cavernicolous scorpions occurring in the Dinaric Karst is provided; and the historical and geographical factors affecting the distribution and conservation of cavernicolous scorpions in the Balkans is reviewed.

Reference:
Blasco-Aróstegui J, Prendini L. Redescription of Euscorpius studentium Based on Adult Specimens; Updated Classification of Cavernicolous Euscorpiidae; and Review of Cavernicolous Scorpions in the Balkans. Diversity. 2024;16(12):737. [Open Access]

Thanks to Gerard Dupre and Siegfried Huber for informing me about this article!

A new cave dwelling Euscorpius from Albania and Northwestern Greece

 

Frantisek Kovarik and co-workers have recently described a new species of Euscorpius Thorell, 1876 (Euscorpiidae) from a unique sulfidic hypogene cave system on the border between Albania and Greece.

 Euscorpius sulfur Kovarik, Audy, Sarbu and Fet, 2023

Even though the new species so far is only found in this cave system, it doesn't show any troglomorphic characters like absence of eyes or reduced pigmentation. The special habitat in the cave system is described.

Abstract:
A new species of cave scorpion, Euscorpius sulfur sp. n. (Scorpiones: Euscorpiidae) from Albania and northwestern Greece is described, fully complemented with color photographs of both live and preserved specimens, as well as their habitats.

Reference:
Kovarik F, Audy M, Sarbu SM, Fet V. Euscorpius sulfur sp. n. (Scorpiones: Euscorpiidae), a new cave scorpion from Albania and northwestern Greece. Euscorpius. 2023(376):1-14. [Open Access]

Family Euscorpiidae

Major work on the phylogeny and systematics of Euscorpiinae in the eastern Adriatic region

 

The systematics and taxonomy of the members of the family Euscorpiidae is still a major challenge in site of numerous research papers in the last decades.  The four traditional European taxa known some decades ago, are now split into a huge diversity of genera and species. And there is still more to come as there are many cryptic species and geographic areas that are still not properly investigated.

Martina Podnar and co-workers have recently published an extensive phylogenetic analysis where they have reviewed the scorpions of the genera Euscorpius Thorell, 1876 and Alpiscorpius Gantenbein et al., 1999 (Euscorpiidae) with a focus on the eastern Adriatic region. 

This is a very extensive study full of new information and data, and some of it is above my head. But the main conclusions are that their analyses point to the existence of several new taxa and the ranges of several species have been revised. In addition they have made the following taxonomic conclusions:

Euscorpius lagostae Di Caporiacco, 1950 from Lastovo Island, Croatia is raised to species status (formerly Euscorpius carpaticus lagostae Di Caporiacco, 1950).

Euscorpius croaticus is moved to the genus Alpiscorpius as Alpiscorpius croaticus (Di Caporiacco, 1950). 

Why do have so many species? The current article indicate that this is probably due to complex topography creating many microhabitats, but also due to microrefugia in the Pleistocene that allowed new taxa to evolve.

Abstract:
The systematics and taxonomy of the scorpion family Euscorpiidae are still unresolved, and, within it, the eastern Adriatic scorpiofauna is largely unknown and under-researched. Based on two mitochondrial sequences (COI and 16S rRNA) and one nuclear marker sequence (ITS1), we put 107 newly analyzed samples originating from the Alps, the Eastern Adriatic, and the adjacent Dinaric karst area into phylogenetic context. Several species delineation approaches were applied to reveal cryptic diversity. Divergence time dating was used to highlight the major events in the evolutionary history of the genera Euscorpius and Alpiscorpius. The deep intraspecific genetic divergences observed in some clades warrant taxonomic revision of several taxa (Euscorpius tergestinus, Euscorpius hadzii, Euscorpius biokovensis, and Euscorpius (Alpiscorpius) croaticus). In this study, the population of E. hadzii from Lastovo Island (formerly Euscorpius carpaticus lagostae) is elevated to species level as Euscorpius lagostae Di Caporiacco, 1950, stat. nov. Euscorpius croaticus is moved to the genus Alpiscorpius as Alpiscorpius croaticus (Di Caporiacco, 1950) comb. nov. The distribution ranges of several species are revised, and based on the new data, a more detailed revision of species distribution is necessary. We attribute the major divergence events to the impact of the Middle Miocene Climate Transition, the Messinian Salinity Crisis, and the Middle Pleistocene Climate Transition. The observed patterns are therefore a direct consequence of the geological history and complex topography of the region, which provided numerous microhabitats, as well as of the Pleistocene microrefugia that enabled their persistence.

Reference:
Podnar M, Grbac I, Tvrtković N, Hörweg C, Haring E. Hidden diversity, ancient divergences, and tentative Pleistocene microrefugia of European scorpions (Euscorpiidae: Euscorpiinae) in the eastern Adriatic region. Journal of Zoological Systematics and Evolutionary Research. 2021;Accepted Manuscript:1-26. [Subscriotion required for full text]

Thanks to Luis Roque for sending me this article.

Family Euscorpidae

Five new species of Euscorpius from Albania, Greece, North Macedonia and Serbia

For the last two decades numerous new cryptic species of Euscorpius Thorell, 1876 (Euscorpiidae) have been described from Europe. This has been possible thanks to molecular phylogenetic in combination with the more traditional morphological characteristics. Frantisek Kovarik and Frantisek Stahlavsky have now published five new species in this genus.

Euscorpius bonacinai Kovarik & Stahlavsky, 2020 (Albania)

Euscorpius janstai Kovarik & Stahlavsky, 2020 (North Macedonia)

Euscorpius kabateki Kovarik & Stahlavsky, 2020 (Greece)

Euscorpius sadileki Kovarik & Stahlavsky, 2020 (Serbia)

Euscorpius scheraboni Kovarik & Stahlavsky, 2020 (Greece)


Two new characteristics for Euscorpius identification are also presented.

Abstract:
Five new species are described: Euscorpius bonacinai sp. n. (Albania), E. janstai sp. n. (North Macedonia), E. kabateki sp. n. (Greece), E. sadileki sp. n. (Serbia), and E. scheraboni sp. n. (Greece), fully complemented with color photographs. New species are distinguished from all other species of the genus on the basis of five taxonomic characters. Two other new characters, shape of the pedipalp chela fingers and number of chromosomes, are presented and discussed. In addition to the analyses of external morphology, we also describe karyotypes of two species: E. janstai sp. n. (2n=112) and E. sadileki sp. n. (2n=90).

Reference:
Kovarik F, Stahlavsky F. Five new species of Euscorpius Thorell, 1876 (Scorpiones: Euscorpiidae) from Albania, Greece, North Macedonia, and Serbia. Euscorpius. 2020(315):1-37. [Open Access]

Family Euscopiidae