23 July, 2019

A new species of Centruroides from western Michoacán State, México

Ana F. Quijano-Ravell and co-workers recently published a new species of Centruroides Marx, 1890 (Buthidae) from western Michoacán State, México.

Centruroides romeroi Quijano-Ravell, De Armas, Francke & Ponce-Saavedra, 2019

A new species of scorpion belonging to the genus Centruroides Marx, 1890 is described from the Coalcomán mountain range, western Michoacán State, Mexico. Its general aspect resembles Centruroides ruana Quijano-Ravell & Ponce Saavedra, 2016, and C. infamatus (C. L. Koch, 1844), but it is a smaller species having lower pectinal tooth counts; also, males of C. ruana have the pedipalp chelae slightly thicker, whereas C. infamatus has a subaculear tubercle nearer to the base of the aculeus. Another species with similar aspect is Centruroides ornatus Pocock, 1902; however, a preliminary molecular analysis of the mitochondrial gene mRNA 16S showed genetic divergence (measured as p-distance) near to 10% between these species, and lower differences between the new species with respect to C. infamatus (4.63%) and C. ruana (5.07%). The molecular evidence together with the morphological characters (integrative taxonomy) are sufficient for recognizing the Coalcomán population as a separate and valid species.

Quijano-Ravell AF, De Armas LF, Francke OF, Ponce-Saavedra J. A new species of the genus Centruroides Marx (Scorpiones, Buthidae) from western Michoacán State, México using molecular and morphological evidence. ZooKeys. 2019(859):31-48. [Open Access]

Thanks to Oscar Francke for sending me their article!

Family Buthidae

A new species in the genus Megachactops from Colombia

Eric Ythier published an article earlier this summer describing a new species in the small genus Megachactops Ochoa, Rojas-Runjac, Pinto-Da-Rocha & Prendini, 2013 (Chactidae) from Colombia.

Megachactops kurripako Ythier, 2019

The article has an identification key for the three species in the genus.

A new species of scorpion belonging to the genus Megachactops Ochoa, Rojas-Runjaic, Pinto-da-Rocha & Prendini, 2013 (family Chactidae Pocock, 1893) is described on the basis of two specimens collected in a rainforest formation located in Puerto Colombia, Guainía, Colombia. This is the third known species of the genus Megachactops, and the first reported from Colombia.

Ythier E. A new species of Megachactops Ochoa, Rojas-Runjaic, Pinto-da-Rocha & Prendini, 2013 (scorpiones: Chactidae) from Colombia. Revista Iberica de Arachnologia. 2019(34):69-75. [Subscription required for full text]

Thanks to Eric for sending me his new article!

Family Chactidae

22 July, 2019

A new species of Hottentotta from Western Ghats, India

Zeeshan Mirza and co-workers recently described a new species of Hottentotta Birula, 1908 (Buthidae) from the Western Ghats, India.

Hottentotta vinchu Mirza, Ambekar & Kulkarni, 2019

The article also has a identification key for the Indian species in the genus Hottentotta.

A new species, Hottentotta vinchu sp. n., is described from the Western Ghats of India. The new species morphologically resembles to Hottentotta rugiscutis (Pocock, 1897) from which it differs in having metasomal segment II wider than long in both sexes. The new species, however, is sister to Hottentotta pachyurus (Pocock, 1897) based on cytochrome oxidase I gene from which it differs in an uncorrected sequence divergence of 7%.

Mirza Z, Ambekar M, Kulkarni NU. A new species of scorpion of the genus Hottentotta Birula, 1908 from the Western Ghats, India (Scorpiones: Buthidae). Arachnida - Rivista Aracnologica Italiana. 2019;5(12):2-16.

Family Buthidae

21 June, 2019

Scorpion venom can kill dangerous, resistant bacterias in a safe way

I usually do not post much about biochemical and toxicology research on scorpion venom as I have very little expertise on these topics. As many of you probably have noticed, there is a lot of research on scorpion venom trying to identify components in the venom that can be used for medical and/or commercial purposes. Because of this, scorpion venom is now considered one of the most expensive materials on earth. This week a very interesting study was published.

Edson Norberto Carcamo-Noriegaa and co-workers have identified twopreviously unknown benzoquinones in the venom of the Mexican scorpion Diplocentrus melici Armas, Martin-Frias & Berea, 2004 (Scorpionidae). The study shows that these two compounds can kill dangerous staphylococcus and tuberculosis bacteria in a safe way. The researchers also were able to synthesize the two compounds, making this a very promising tool for a future medicine against dangerous and resistant bacterias.

If you can not access the article, you can check out this news report from Stanford University summing up the main findings.

Two 1,4-benzoquinone derivatives, found in the venom of the scorpion Diplocentrus melici following exposure to air, have been isolated, characterized, synthesized, and assessed for antimicrobial activities. Initially a white, viscous liquid, the extracted venom colors within minutes under ambient conditions. From this colored mixture, two compounds, one red, the other blue, were isolated and purified using chromatography. After a variety of NMR and mass spectrometry experiments, the red compound was determined to be 3,5- dimethoxy-2-(methylthio)cyclohexa-2,5-diene-1,4-dione, and the blue compound was determined to be 5-methoxy-2,3- bis(methylthio) cyclohexa-2,5-diene-1,4-dione. Because extremely small amounts of these compounds were isolated from the scorpion venom, we developed laboratory syntheses from commercially available precursors, allowing us to produce sufficient quantities for crystallization nd biological assays. The red benzoquinone is effective against Staphylococcus aureus [minimum inhibitory concentration (MIC) = 4 μg/mL], while the blue benzoquinone is active against Mycobacterium tuberculosis (MIC = 4 μg/mL) and even against a multidrug-resistant (MDR) strain with nearly equal effectiveness. The bactericidal effects of both benzoquinones show comparable activity to commercially available antibiotics used against these pathogens and were cytotoxic to neoplastic cell lines, suggesting
their potential as lead compounds for the development of novel antimicrobial and anticancer drugs. Importantly, the blue benzoquinone was also effective in vivo with mouse models of MDR tuberculosis infection. After treatment for 2 mo, four mice with late-stage active MDR tuberculosis had a significant decrease in pulmonary bacillary loads and tissue damage. Healthy mice served as negative controls and tolerated treatment well, without adverse side effects.

Carcamo-Noriega EN, Sathyamoorthi S, Banerjee S, Gnanamani E, Mendoza-Trujillo M, Mata-Espinosa D, et al. 1,4-Benzoquinone antimicrobial agents against Staphylococcus aureus and Mycobacterium tuberculosis derived from scorpion venom. Proceedings of the National Academy of Sciences. 2019:201812334. [Subscription required for full text]

Thanks to Matt Simon for informing me about this interesting article!

20 June, 2019

A new species of Euscorpiops from China

Eric Ythier has recently published a new species of Euscorpiops Vachon, 1980 (Euscorpiidae) from China.

Euscorpiops zhangshuyuani Ythier, 2019

An identification key for the genus in the Yunnan Province is included.

A new species of scorpion belonging to the genus Euscorpiops Vachon, 1980 (family Scorpiopidae Kraepelin, 1905) is described on the basis of two adult females collected in a montane rainforest formation located in Tong Bi Guan Xiang, Yingjiang County, Yunnan Province, China, close to the border with Myanmar. This new scorpion taxon represents the 27th known species of the genus Euscorpiops, the tenth reported from China and the eighth reported from Yunnan Province.

Ythier E. A new species of Euscorpiops Vachon, 1980, from China (Scorpiones, Scorpiopidae). Bulletin de la Société entomologique de France. 2019;124(2):189-96. [Subscription required for full text]

Thanks to Eric Ythier for sending me his article!

Family Euscorpiidae

12 June, 2019

Two new species of Hottentotta from Iran and Pakistan

Frantisek Kovarik and co-workers have published an article where the revise the species of Hottentotta Birula, 1908 (Buthidae) described by the famous Russian arachnologist Alexei A. Byalynitskii-Birulya (or A. A. Birula).

Two new species are described:

Hottentotta juliae Kovarik, Yagmur & Fet, 2019 (Iran)

Hottentotta krivokhatskyi Kovarik, Yagmur & Fet, 2019 (Pakistan)

See abstract and article for further taxonomical conclusions.

The types of Hottentotta species described by A. A. Birula and deposited in the Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia are revised. The types of H. buchariensis (Birula, 1897), H. niloticus (Birula, 1928), H. penjabensis (Birula, 1897) stat. nov. and H. schach (Birula, 1905) are fully illustrated with color photographs of morphology. Their taxonomic position is discussed. Lectotypes are designated for H. niloticus and H. schach. We confirm synonymy of Buthus (Hottentotta) minax niloticus Birula, 1928 (Sudan) with Buthus minax L. Koch, 1875, syn. n. Two new species, Hottentotta juliae sp. n. from Iran (Fars Province) and H. krivokhatskyi sp. n. from Pakistan (Balochistan Province), are described, based on specimens which were in previous publications incorrectly identified as H. schach and H. penjabensis.

Kovarik F, Yagmur EA, Fet V. Review of Hottentotta described by A. A. Birula, with descriptions of two new species and comments on Birula’s collection (Scorpiones: Buthidae). Euscorpius. 2019(282):1-30. [Open Access]

Family Buthidae

31 May, 2019

Mating in scorpions: Better condition = More successful reproduction?

Sexual selection often favors larger body size and/or greater weight in males. Larger males have better condition and are able to perform more impressive courtships, and because of this, will be more attractive for females. This may also be the case in scorpions.

Oliverio and co-workers have published a paper studying mating and courtship behavior in Bothriurus bonariensis (C.L. Koch, 1842) (Bothriuridae) and relating this to the size and body condition of both males and females.

The results showed that better condition (larger size) provided a mating advantage to males (e. g. larger males performed the mating dance quicker than smaller males) and that sexual selection is acting on courtship in B. bonariensis.

In most animal species, body condition has a fundamental role in fitness. In males, sexual selection generally favors larger body size or greater weight. This may result in males with better condition performing more vigorous courtships, and biasing female preferences. The effects of body condition on mating performance have been extensively studied in different animal groups. Among arachnids, scorpions are an interesting group for evaluating the effects of these sexual traits on mating performance, since they exhibit an ancient mode of indirect sperm transfer. Scorpion males deposit a single spermatophore on the soil to transfer the sperm to the females, and therefore, the production of spermatophores involves a high cost for them. In this study, we use the scorpion Bothriurus bonariensis as a model to evaluate different patterns of sexual behavior as a function of the body condition of both males and females. We found that males with a better body condition performed the mating dance stage more quickly than males with a lower condition. In addition, males performed the sexual sting behavior for a longer time with females in a better condition. Our results suggest that a better condition provides a mating advantage to males and represents an indicator of courtship performance. Given that female quality is usually correlated with fecundity, males mating with females with a better body condition probably have higher reproductive success.

Olivero PA, Vrech DE, Oviedo-Diego MA, Mattoni CI, Peretti AV. Courtship performance as function of body condition in an ‘ancient’ form of sperm transfer. Animal Biology. 2019;69:33-46. [Open Access]

Thanks to Camilio Mattoni for sending me their article!