25 January, 2018

The effect of habitat loss and habitat restoration on scorpions in the Brazilian Atlantic Forest

Andre Lira and co-workers have recently published a study on the effects of habitat loss in scorpions in the Brazilian Atlantic Forest. The study also looks at the status on the populations after the original habitat is being restored and what other factors may affect the populations.

Habitat loss due to forest degradation can induce changes in species richness due to variation in species susceptibility to environmental stress. This is particularly important for species with highly specific microhabitats, such as scorpions that inhabit forest habitats. In this study, the richness and abundance of these arachnids were compared between an old-growth (mature) and secondary (65 years under natural restoration) forests. Seasonal influence was also evaluated by comparing diversity between dry and wet seasons. The animals were collected through nocturnal active search using UV lamps and pitfall traps in both areas (old-growth and secondary). Both environments showed similar breast heights of trees, litter depth, litter dry mass, and understory density, indicating a high level of restoration. Scorpion diversity (characterized by Tityus pusillus, T. neglectus, T. brazilae, Bothriurus asper, and Ananteris mauryi) and abundance were not influenced by the different historical usage of both areas. In contrast, the abundance of these arachnids was highly affected by rain regimes, and increased during the dry season. These results suggest that 65 years was a sufficient time period for restoration, making it possible to maintain similar scorpion assemblages in both environments.

de Araujo Lira AF, Damasceno EM, Silva-Filho AAC, Albuquerque CMRd. Linking scorpion (Arachnida: Scorpiones) assemblage with fragment restoration in the Brazilian Atlantic Forest. Studies on Neotropical Fauna and Environment. 2017:1-6. [Subscription required for full text]

Thanks to Andre Lira for sending me their paper!

23 January, 2018

On the distribution of the genus Opisthacanthus and a new species

Wilson Lourenco has recently published an updated review of the geographic distribution and the biogeography of the genus Opisthacanthus Peters, 1861 (Hormuridae). This interesting genus is found both in parts of Africa, Madagascar and in South America.

A new species from Madagascar is also described.

Opisthacanthus titanus Lourenco, 2018

In this article I discovered an valid Opisthacanthus species that was not listed in The Scorpion Files.

Opisthacanthus heurtaultae Lourenco, 1980

This species was previously synonymized, but restored in 1995 by Lourenco. This was not mentioned in the sources that I used to build The Scorpion Files. The species is now listed as valid.

New comments are proposed on the geographic distribution of genus Opisthacanthus, and the Gondwanian model is further supported. The diversity of the genus is extraordinary in Madagascar, with the same number of species as in continental Africa, but sub-Saharan Africa is home to six out of the nine groups currently recognized of Opisthacanthus. Given the affinities of the Opisthacanthus groups and their current distribution, a center of origin in Africa could be favored for these ancient scorpions. The proposed Gondwana model suggests that the Madagascar Opisthacanthus are closer to those of the New World, which is consistent with the affinities observed in morphological characters. A new species, Opisthacanthus titanus sp. n., is described from the Torotorofotsy Forest, located in Eastern Madagascar. The new species shows affinities with both Opisthacanthus madagascariensis Kraepelin, 1894 known from dry regions in the western portion of the island and Opisthacanthus lavasoa Lourenc¸o, Wilme´ & Waeber, 2016 only known from the extreme southeast of the island. The new species and O. madagascariensis have similar external morphologies but the morphometric values are markedly distinct. Moreover, O. madagascariensis is exclusively found in spiny forest thickets and open woodlands, whereas the new species was found in the humid forest of Torotorofotsy. The total number of species in Madagascar is now raised to twelve. Biogeographical scenarios are also proposed to infer the origin of the Opisthacanthus and better understand its distribution in the New World, in Africa and Madagascar.

Lourenco WR, Wilme L, Waeber PO. The genus Opisthacanthus Peters, 1861 (Scorpiones: Hormuridae), a remarkable Gondwanian group of scorpions. C R Biol. 2018, In Press. [Subscription required for full text]

Lourenco WR. Nouvelles considérations sur la classification et la biogéographie des Opisthacanthus néotropicaux (Scorpiones, Ischnuridae). Biogeographica. 1995;71(2):75-82.

Family Hormuridae

17 January, 2018

A new species of Tityus from Ecuador

A new species of Tityus C. L. Koch, 1876 (Buthidae) has recently been described from Ecuador by Wilson Lourenco and Eric Ythier.

Tityus cisandinus Lourenço & Ythier, 2017

I have only read the abstract of this article as authors publishing in Arachnida - Rivista Aracnologica Italiana are not allowed to send pdfs/copies of their article to other scientists (contrary to the practice of most other scientific journals) and my library's interlending department are not able to get copies either.

The status of the enigmatic buthid scorpion Tityus asthenes Pocock, 1893 is once more discussed. Described from Poruru in Peru, the species remains known by the female holotype only. A reanalysis of the several characteristics of the holotype demonstrates that the species is valid, but not a member of the subgenus Atreus (group Tityus americanus as suggested by Pocock) but rather belongs to the subgenus Tityus and to the group of Tityus bolivianus, consequently distinct from all other populations of Tityus (Atreus) distributed from Ecuador to Costa Rica. Previous suggestions that T. asthenes could represent a senior synonym of several other Tityus (Atreus) species were due to inadequate interpretations of their biogeographic pattern of distribution. Although the validity of Tityus asthenes is unquestionable, its precise range of distribution remains enigmatic since its type locality Poruru is not known from Peru and no further details are available about the collection of this species. A new species of Tityus (Atreus) is described from the cis-Andean rainforests of Ecuador and some taxonomic considerations are proposed for some related species within the subgenus Atreus.

Lourenco WR, Ythier E. Another new species from the rainforests of Ecuador (Tityus cisandinus Lourenço & Ythier, 2017). Arachnida - Rivista Aracnologica Italiana. 2017;3(15):18-34.

Thanks to Eric Ythier for informing me about their article and for allowing me to use a picture from the article.

Family Buthidae 

16 January, 2018

A comparative cytogenetic study of a three Hadogenes species results in a new species from South Africa

Frantisek Stahlavsky and co-workers have recently published the first comparative cytogenetic study in Hadogenes species (Hormuridae) using both standard and molecular cytogenetic approaches. A new species from South Africa is also described.

Hadogenes weygoldti Stahlavsky, Stundlova, Lowe, Stockmann & Kovarik, 2018

In the present study, we performed the first comparative cytogenetic study in Hadogenes species using both standard and molecular cytogenetic approaches. Information about the diploid set, number and distribution of 18S rDNA and telomeric sequences was obtained from three South African species, Hadogenes trichiurus (Gervais, 1843), H. zuluanus Lawrence, 1937 and H. weygoldti sp. n. All species analysed differ considerably in the number of chromosomes (H. trichiurus 2n=48, H. zuluanus 2n=80, H. weygoldti sp. n. 2n=113). In contrast, the number of 18S rDNA clusters and distribution of telomeric sequences represent rather stable cytogenetic characters in Hadogenes. Within all karyotypes, we identified one pair of 18S rDNA clusters. The telomeric signals were exclusively on the terminal chromosomal regions. Interestingly, the chromosomal location of 18S rDNA clusters varied from terminal to interstitial in species karyotypes, indicating the presence of hidden structural chromosomal changes. Additionally, the present comparative study is complemented by the description of a new species, H. weygoldti sp. n., based on specific karyotype features and morphological characters. Finally, our cytogenetic results are compared with known chromosomal data of other Hadogenes species, and the use of cytogenetic approaches in the taxonomy of scorpions is discussed.

Šťáhlavský F, Štundlová J, Lowe G, Stockmann M, Kovařík F. Application of cytogenetic markers in the taxonomy of flat rock scorpions (Scorpiones: Hormuridae), with the description of Hadogenes weygoldti sp. n. Zoologischer Anzeiger. 2018;Accepted Manuscript. [Subscritpion required for full text]

Family Hormuridae

11 January, 2018

The evolution of dangerous scorpions and their distribution

Wilson Lourenco has recently published an interesting article where he discuss the evolution of scorpion venom and why some species are more dangerous to humans than others. The article also discuss the global distribution of dangerous species. The article mainly focus on the family Buthidae, where we find most dangerous scorpions.

The article is written in a popular science language making it interesting for both experts and laypersons.

This contribution attempts to bring some general information on the evolution and, in particular, on the geographic distribution of scorpion species noxious to humans. Since 95% of the scorpions incidents are generated by specimens of the family Buthidae C. L. Koch, the analysis will be limited to this familial group. As in previous similar contributions, the content of this work is mostly addressed to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. Only in recent years, efforts have been made to create better links between ‘academic scorpion experts’ and other academic non-specialists who use scorpions in their research. Even if a larger progress can yet be expected from such exchanges, crossed information proved to be useful in most fields of scorpion studies. Since the taxonomy of scorpions is complex, misidentifications and even more serious errors concerning scorpion classification/ identification are often present in the general literature. Consequently, a precise knowledge of the distribution patterns presented by many scorpion groups and, in particular, those of infamous species, proves to be a key point in the interpretation of final results, leading to a better treatment of the problems caused by infamous scorpion species.

Lourenco WR. The evolution and distribution of noxious species of scorpions (Arachnida: Scorpiones). J Venom Anim Toxins Incl Trop Dis. 2018;24:1. [Open Access]

03 January, 2018

A review of the scorpion fauna of Egypt

Ahmed Badry and co-workers have recently published a review of the scorpion fauna of Egypt. A total of 35 species belonging to four families are reported, of which 6 are endemic to Egypt. The article has an identification guide for the Egyptian taxa. 

The article also has interesting information about the different species' habitat preferences. 

There is a supplement to the article on the article homepage with location information and color pictures of most of the species reported from Egypt.

The taxonomy and diversity of the scorpion fauna of Egypt was examined based on a large collection from most parts of the
country and in view of recent revisionary systematics. We assessed the validity of listed records in light of new taxonomic findings and geographic distribution data and present a new list and an identification key to the scorpion fauna of Egypt consisting of 31 species, 18 of which were collected during this survey. Four species were not accepted for the list because no voucher material was available.

Badry A, Younes M, Sarhan MMH, Saleh M. On the scorpion fauna of Egypt, with an identification key (Arachnida: Scorpiones). Zoology in the Middle East. 2017:1-13. [Subscription required for full text]

Thanks to Dr. Ahmed Badry for sending me their article!

02 January, 2018

A new Euscorpius from Northwestern Turkey

Ersen Yagmur and Gioele Tropea have recently published a new species of Euscorpius Thorell, 1876 (Euscorpiidae) from the Balıkesir and Çanakkale provinces in northwestern Turkey.

Euscorpius idaeus Yagmur & Tropea, 2017

Euscorpius idaeus sp. n. is described from Balıkesir and Çanakkale provinces, from northwestern Turkey, based on morphological evidences. This description raises to 18 the Euscorpius species currently recognized in Turkey.

Yagmur EA, Tropea G. A new species of Euscorpius Thorell, 1876 from Mountain Kazdağı in northwestern Turkey (Scorpiones: Euscorpiidae). Arachnida - Rivista Aracnologica Italiana. 2017;3(15):2-17.

Thanks to Ersen Yagmur for sending me their article!

Family Euscorpiidae