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!

Phylogenetic analysis reveal cryptic subspecies of Euscorpius borovaglavaensis in Croatia

 

The genus Euscorpius Thorell, 1876 (Euscorpiidae) from Europa has become notorious for its hidden, cryptic species. A few decades ago this genus consisted of less than 10 species, today the number of taxa is closed to 100.

Martina Podvar and co-workers have publised a phylogenetic and phylogeographic  study of the populations of Euscorpius borovaglavaensis Tropea, 2015 in Croatia. Two distinct lineages were discovered and the population distributed in the northwestern part of the range was given subspecies status.

Euscorpius borovaglavaensis flavus Vignoli, 2024

Abstract:
The European scorpion Euscorpius borovaglavaensis Tropea, 2015 is a morphologically cryptic species that is distinguishable only with difficulty from E. tergestinus (C. L. Koch, 1837). It is distributed in the middle part of the Dinaric Alps chain and along part of the Eastern Adriatic coast, specifically, in Croatia (Middle Dalmatia, Lika karst upland), as well as in the southern part of Bosnia and Herzegovina. The new findings reported here have enhanced our knowledge of its geographic distribution in Croatia. Detailed morphological analyses highlighted the importance of carination in the ventral metasomal segments as morphological traits. Phylogenetic analyses, based on the mitochondrial cytochrome c oxidase subunit I (COI) gene, have revealed the existence of two distinct lineages. One of them, distributed in the northwestern part of the range, is described here as E. b. flavus n. ssp., while the nominal subspecies occurs in the southeastern part. A time-calibrated phylogenetic analysis has established their divergence around 0.9 million years ago, coinciding with the Mid-Pleistocene Transition (MPT) period. In contrast to the nominal subspecies, E. b. flavus n. ssp. exhibits significant phylogeographic structuring, indicating recent isolation events in multiple glacial microrefugia after the initial divergence, followed by a final Holocene dispersal in the northwestern direction deep between the mountain chains.

Reference:
Podnar M, Vignoli V, Tvrtković N. Phylogeographic structuring within recently diverged scorpion species, Euscorpius borovaglavaensis Tropea, 2015 (Scorpiones: Euscorpiidae) in Croatia, with the description of a new subspecies. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici. 2024;33(1):29-52. [Open Access]

Thanks to Valerio and Gerard who both sent me this article!

Family Euscorpiidae

A new species of Alpiscorpius from Croatia

 

Martina Podnar and co-workers have recently described a new species of Alpiscorpius Gantenbein et al., 1999 (Euscorpiidae) from Krk Island, Croatia.

Alpiscorpius liburnicus Tvrtkovic & Rebrina, 2022

The new species was found in caves, but showed no troglomorphic adaptations.

Abstract:
Alpiscorpius liburnicus sp. n. is described from Krk Island, Croatia, as the first cave dwelling scorpion species in the genus. Clear differences from the genetically closest epigean species were found in metasomal morphometry. Its delineation is supported phylogenetically based on mitochondrial (COI and 16S rRNA) and nuclear (ITS1) markers. In the barcode fragment of the mitochondrial cytochrome oxidase subunit 1 gene (COI), the uncorrected pairwise genetic distances to other known taxa in “Alpiscorpius croaticus group” range between 4.2 and 4.8 %. The first molecular evidence of the species’ presence on the coastal part of Mt. Velebit implies its potential distribution in the whole of the eastern Adriatic coastal area, roughly from Rijeka City area to the source of the Zrmanja River. The new species is sympatric with common epigean taxa of the “Euscorpius tergestinus group” and with the synanthropic E. italicus in Mediterranean habitats. The phylogenetic relationships within the “A. croaticus group” are estimated. Localities of epigean A. croaticus are restricted to the continental side of southern and southeastern parts of Mt. Velebit. There it is sympatric and syntopic with the smaller A. omega in karst beech forests, with an extrazonal enclave in the Velika Paklenica canyon area on the southern slopes of the mountain. The third taxon in the group is known at the moment from a single locality in the middle part of Mt. Velebit, where it is also syntopic with A. omega in a beech forest near limestone cliffs.

Reference
Podnar M, Tvrtković N, Vuković M, Rebrina F, Grbac I, Hörweg C. Alpiscorpius liburnicus sp. n. with a note on the “Alpiscorpius croaticus group”(Scorpiones: Euscorpiidae) in Croatia. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici. 2022;31(2):265-82. [Open Access]

Thanks to Siegfried Huber for sending me this article!

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

A new species of Euscorpius from caves in Croatia and Bosnia-Herzegovina

Gioele Tropea and Roman Ozimec have recently published an article describing a new species of Euscorpius Thorell, 1876 (Euscirpiidae) found in more than 20 cave systems in Croatia and Bosnia-Herzegovina.

Euscorpius biokovensis Tropea & Ozimec, 2020

Ecological notes for the new species are presented and its cave preference is discussed.

Abstract:
Another new, subtroglophile scorpion species is described from Croatia, Euscorpius biokovensis sp. n. It is morphologically and ecologically similar to E. feti Tropea, 2013 but can be distinguished from the latter by a lower number of trichobothria (Pv = 8–9, with mostly 8, and usually et = 6) and pectinal teeth (usually Dp = 7 in males and 6 in females). The new species also has a more northern distribution although in some areas the two species overlap. E. biokovensis sp. n. has been found in more than 20 caves in Croatia, which makes it the most common Euscorpius species found in caves. It has also been found in Bosnia-Herzegovina. Ecological notes on this species are presented.

Reference:
Tropea G, Ozimec R. Another new species of Euscorpius Thorell, 1876 from the caves of Croatia and Bosnia-Herzegovina (Scorpiones: Euscorpiidae), with notes on biogeography and cave ecology. Euscorpius. 2020(308):1-13. [Open Access]

Thanks to Gioele for sending me their article!

Family Euscorpiidae

New information on Euscorpius feti from the Balkans

Gioele Tropea and Roman Ozimec have recently published an article with new information on Euscorpius feti Tropea, 2013 (Euscorpiidae). The adult male is described for the first time. In addition, the occurrence of E. feti in cave habitats (especially the habitat of cave entrance) is discussed.

Abstract:
The adult male of Euscorpius feti Tropea, 2013 (Euscorpiidae) is described for the first time. A large series (45 specimens including the type material) has been studied, most of the material previously unpublished. E. feti has been found in as many as 17 caves in Croatia and Bosnia-Herzegovina, including the Adriatic islands, which makes it the most common Euscorpius species so far found in caves. Ecological notes on this species are presented.

Reference:
Tropea G, Ozimec R. Description of the adult male of Euscorpius feti Tropea, 2013 (Scorpiones: Euscorpiidae), with notes on cave ecology of this species. Euscorpius. 2019(291):1-10. [Open Access]

Family Euscorpiidae

A revision of some Italian populations of Euscorpius with five new species

Gioele Tropea published an article in 2017 where he studied several populations of Euscorpius sicanus (C. L. Koch, 1872) (Euscorpiidae) in Italy. I just recently learned about this article, but better late than never.

Tropea's analyses show that Euscorpius sicanus is a species complex and he have done the following taxonomical deccisions:

New species:

Euscorpius altadonnai Tropea, 2017 (Northeastern Sicily and southern Calabria, Italy)
Euscorpius salentinus Tropea, 2017 (Southern Puglia (Salento), Italy)

The following species have been raised to species status from synonymy with Euscorpius sicanus:

Euscorpius calabriae Di Caporiacco, 1950 (Calbria and Basilicata (southern part), Italy)
Euscorpius canestrinii (Fanzago, 1872) (Sardinia, Italy)
Euscorpius garganicus Di Caporiacco, 1950 (Puglia, Molise, Campania and Basilicata, Italy and Pelagosa Island, Croatia)

Abstract:
After Fet et al. (2003), Euscorpius sicanus (C. L. Koch, 1837) was considered a highly polymorphic species, widespread in Italy, North Africa, Malta and Greece, having the characters eb = 5 + eba = 45. In this study, a neotype is designated for E. sicanus. The following forms, synonymized with E. sicanus by Fet et al. (2003), are herein revalidated and elevated to species status: E. calabriae Di Caporiacco, 1950 stat. n.; E. canestrinii (Fanzago, 1872) stat. n.; E. garganicus Di Caporiacco, 1950 stat. n. The latter species is herein recorded for the first time in the Italian regions of Molise and Campania, and in Pelagosa Island, Croatia. Two new species and one new subspecies are described, E. salentinus sp. n. from southern Apulia, E. altadonnai sp. n. from northeastern Sicily and southern Calabria, and E. garganicus molisanus subsp. n. from northeastern Apulia, Molise and southeastern Abruzzo. With these taxonomic changes the number of species in Italy has increased to 18.

Reference:
Tropea G. Reconsideration of some populations of Euscorpius sicanus complex in Italy (Scorpiones: Euscorpiidae). Arachnida - Rivista Aracnologica Italiana. 2017;3(11):2-60.

Thanks to Gioele Tropea for sending me his interesting article!

Family Euscorpiidae
 

New Euscorpius species from western Balkans

Gioele Tropea has recently described a new species of Euscorpius Thorell, 1876 (Euscorpiidae) from Bosnia and Herzegovina and Croatia.

Euscorpius borovaglavaensis Tropea, 2015

Abstract:
A new species of scorpion, Euscorpius borovaglavaensis sp. n. from Bosnia-Herzegovina and Croatia, in Western Balkans, is described. It is similar to Euscorpius tergestinus (C. L. Koch, 1837), but with a dark brown color and a more south-eastern distribution.

Reference:
Tropea G. A new species of Euscorpius Thorell, 1876 from Bosnia-Herzegovina and Croatia (Scorpiones: Euscorpiidae). Arachnida - Rivista Aracnologica Italiana. 2015;1(5):30-41.

Thanks to Dr. Tropea for sending me his article!

Family Euscorpiidae

A new Euscorpius from Western Balkans

The new species, Euscorpius feti, is named after leading Euscorpius expert professor Victor Fet.

Gioele Tropea is continuing his studies on the populations of Euscorpius Thorell, 1876 (Euscorpiidae) in Europe. Today's news is a new species of Euscorpius from Western Balkan (Western Bosnia & Herzegovina, southern Croatia, northwestern Montenegro).

Euscorpius feti Tropea, 2013

Abstract:
A new scorpion species, Euscorpius feti sp. n., is described from the western Balkans based on morphological evidence. It is characterized by long-limbed overall appearance, medium-large size, light brown to reddish color, and a high trichobothrial count (Pv = 11–12, et = 8, em = 4 and eb = 4).

Reference:
Tropea G. A New Species of Euscorpius Thorell, 1876 from the Western Balkans (Scorpiones: Euscorpiidae). Euscorpius. 2013 (174):1-10. [Free full text]

Thanks to Gioele Tropea for sending me his article!

Family Euscorpiidae

New Euscorpius discovered

Gioele Tropea has looked into Euscorpius tergestinus (C. L. Koch, 1837) (Euscorpiidae) and discovered that this widespread, polymorphic species actually is two distinct species. Populations previously named Euscorpius carpathicus aquilejensis (C. L. Koch, 1837) (which has been in synonymy with E. tergestinus (C. L. Koch, 1837)), are now given species status. The new species' name is Euscorpius aquilejensis (C. L. Koch, 1837).

Euscorpius aquilejensis (C. L. Koch, 1837): Restricted to northern and central Italy, San Marino, Vatican City State, western Slovenia, northwestern Croatia.

Euscorpius tergestinus (C. L. Koch, 1837): Restricted to Italy (extreme northeast), Slovenia, Croatia, Austria (introduced) and Czech Republic (introduced)

Both morphological and genetic data confirm the validity of the two species.

Abstract:
After the revision of Fet & Soleglad (2002), Euscorpius tergestinus (C. L. Koch, 1837) was considered a polymorphic species widespread from France to Croatia. In this study, we reconsidered the taxonomy of E. tergestinus s.str. based on morphological and genetic evidence, its range, and its original description. Euscorpius aquilejensis (C. L. Koch, 1837), stat. nov., previously synonymous with E. tergestinus, is elevated to species status herein. A preliminary phylogenetic analysis based on available GenBank 16S rDNA data shows a separate, basal position of E. aquilejensis and some other Euscorpius species, which implies that the subgenus Euscorpius s.str. is paraphyletic.

Reference:
Tropea G. Reconsideration of the taxonomy of Euscorpius tergestinus (Scorpiones: Euscorpiidae). Euscorpius. 2013 (162):1-23. [Free full text]

Family Euscorpiidae 

Thanks to Gioele Tropea for sending me his new article!

Euscorpius croaticus from Croatia raised to species status

"Hidden" Euscorpius species are still waiting to be discovered in Europe, especially in Greece and in the Balkans. Matthew Graham and co-workers have now raised Euscorpius germanus croaticus Di Caporiacco, 1950 (Euscorpiidae) to species status based on molecular and morphological evidence.

Euscorpius croaticus Di Caporiacco, 1950

Abstract:
The taxonomic identity of Euscorpius germanus croaticus Di Caporiacco, 1950, described from Croatia and Bosnia, has remained unclear ever since its discovery. We studied the lectotype from the Velebit Mountains as well as new material from Biserujka Cave on Krk Island, Croatia. We reassessed E. g. croaticus using both morphology and DNA barcodes (cox1 sequences) from one of the Biserujka Cave specimens and 15 congeneric species. The resulting DNA phylogeny suggests that E. g. croaticus is not a subspecies of E. germanus. The taxon appears to be a separate lineage, which groups close to subgenus Alpiscorpius but differs from all its members in several morphological characters. We elevate E. g. croaticus to species rank as Euscorpius croaticus Di Caporiacco, 1950, stat. nov., and provide a detailed redescription of both sexes.

Reference:
Graham MR, Webber MM, Blagoev G, Ivanova N, Fet V. Molecular and morphological evidence supports the elevation of Euscorpius germanus croaticus Di Caporiacco, 1950 (Scorpiones: Euscorpiidae) to E. Croaticus Stat. Nov., a rare species from croatia. Revista Iberica de Arachnologia. 2012 (21):41-50.

Thanks to Professor Victor Fet for sending me this paper!

Family Euscorpiidae