Offspring growth and development in two buthid scorpions from Azerbaijan

Growth and biological development in scorpions vary between species and their habitat, climate and feeding ecology. Nizami E. Novruzov has recently published a laboratory study of the above in the two buthid species Olivierus caucasicus (Nordmann, 1840) and Mesobuthus eupeus (C.L. Koch, 1839) from Azerbaijan. See abstract and article for details.

Abstract:
The main aspects of offspring growth in two scorpion species – Mesobuthus eupeus and Olivierus caucasicus were studied. The entire reproductive cycle – mating, pregnancy of females, birth of the offspring and their growth until adulthood – took place in laboratory conditions. The duration, rate, and intensity of growth, as well as the dynamics of body weight changes and some metric traits during post-embryonic ontogenesis were studied. The growth of young scorpions was uneven, with growth periods of varying lengths: from larva to third molt – an average of 6.2 months, from the fourth molt to the sixth (imago) – an average of 12.6 months (M. eupeus); and an average of 7.7 and 14.1 months (O. caucasicus). By duration of development, M. eupeus nymphs were ahead of O. caucasicus nymphs: on average by 9.2±2.8 days in early post-larval ontogenesis and by 15.0±3.5 days in late post larval ontogenesis. Of the entire growth cycle, 4/5 occurred during molting, the remaining 1/5 occurred in the periods between molting. Species-specific and sex-specific differences in the dynamics of changes in linear characters and body weight were identified. Sexual dimorphism was also evident in faster development, a greater number of molts, and a longer lifespan in females compared to males. Changes in growth rate and intensity tended to increase at the beginning of development and decrease at the end. Nymphs of both species also showed some decrease in growth rate and weight gain during periods of no feeding activity before molting and during periods chronologically corresponding to their natural diapause in the wild.

Reference:
Novruzov NE. Comparative dynamics of offspring growth in Mesobuthus eupeus (C.L. Koch, 1839) and Olivierus caucasicus (Nordmann, 1840) (Scorpiones: Buthidae). Serket. 2026;21(2):158–74. [Open Access]

Thanks to Hisham El-Hennaway for sending me the article! 

A new species of Olivierus from Eastern Iran

 

Niloofar Hashemzahia and co-workers have recently published an article on the scorpion fauna of Nehbandan County, Eastern Iran. I new species of Olivierus Farzanpay, 1987 (Buthidae) is described.

Olivierus simabina Barahoei, 2026

Abstract:
Given the lack of research on scorpion species in South Khorasan province, this study is deemed necessary. Understanding the scorpion fauna and its seasonal occurrence is essential for effectively preventing and treating scorpion stings. Sampling was done evenly using an ultraviolet light at night or direct observation during the day. In this study, 141 specimens were collected from different parts of Nehbandan county. Five species belonging to five genera of the Buthidae were collected and identified, the first four being Androctonus orientalis (Birula), Mesobuthus rakhshanii Barahoei, Odontobuthus tirgari Mirshamsi et al. and Sassanidotus gracilis (Birula). Olivierus simabina Barahoei sp. n. was also described, and its record was added to the scorpion fauna of Iran. No other species except for O. tirgari has been recorded from Nehbandan. Sassanidotus gracilis is a new report for the fauna of the South Khorasan province.

Reference:
Hashemzahi N, Ravan S, Barahoei H. New species and faunal records of the scorpions of Nehbandan County, eastern Iran (Scorpiones: Buthidae). Journal of Natural History. 2026;60(25-28):1431–46. [Subscription required for full text]

Family Buthidae 

Six cases of cannibalism from Turkey

 

Cannibalism has been reported in scorpions on several occasions. Predatory cannibalism is probably most common, but sexual cannibalism has also known to occur. Generally, a larger scorpion eats a smaller scorpion.

Recently, Ersen Yagmur and co-workers published a study of six cases of cannibalism in five buthid species in Turkey. The cases and cannibalism in scorpions in general are discussed in the article.

Abstract:
No abstract.

Reference:
Yagmur EA, Lira AFdA, Kurt R, Tezcan E, Kartal I, Sipahioglu Ö. Does size matter? Reports of cannibalism in scorpions (Scorpiones: Buthidae) from Turkey. North-Western Journal of Zoology. 2025;21(1):90–2. [Open Access]

Thanks to Ersen for sending me their article!

Survival strategies of first-instar scorplings of Olivierus martensii

 

Ecdysis (molting, changing skin) is the way that scorpions and many other arthropods grow. This is a risky part of an young scorpions life, especially during the first molts. Yiyuan Guo and co-workers have recently published a study on the strategies used by first-instar scorplings of Olivierus martensii (Karsch, 1879) (Buthidae) to optimize survival (the article use the old name for this species, Mesobuthus martensii). 

The study shows that newborn scorpions exhibit special aggregate molting behavior, which increases their chances of survival. This aggregating behavior makes it easier for the mother scorpion to keep the scorplings on her back, even though this behavior is also observed when scorplings molt away from the mother's back. The cooperative nature of aggregate molting in first-instars combined with staying on the mother's back and in her care is probably an essential role in increasing the survival of the young scorplings.

Abstract:
Ecdysis is a well-known developmental feature among arthropods. Because the aggregate and synchronous molting of first-instar scorpions is markedly different from the common independent molting behavior of older scorpions and most arthropods, knowledge on the biological benefits of the unusual behavior of first-instar scorpions remain limited. Before the molting of newborn scorpions, their mothers exhibited a remarkable ability to efficiently locate the fallen offspring and help them climb onto their back, which was supported by strong maternal behavior because they climbed more swiftly than the 7-day postpartum scorpions. Most newborn scorpions molted and survived on the mother’s back, with a survival rate of approximately 100%, and most newborn scorpions survived via aggregate molting behavior on sand in the absence of mothers (89.83% ± 1.91%). The important role of the mother scorpion was further highlighted in mothers with one to five first-instar scorpions.While all first-instar scorpions individually or reciprocally molted and survived on the mother’s back, only 52.00% ± 7.14% to 79.20% ± 4.24% of newborn scorpions isolated from the mother could individually or reciprocally molt and survive on the sand, and the aggregated states of first-instar scorpions strengthened as their numbers on sand increased before molting. These results highlight collaborative molting as an evolutionary driving force for newborn scorpions. Taken together, both maternal care and collaborative aggregate molting behavior enhanced the survival of first-instar scorpions before and after molting, and these benefits for first-instar scorpions play essential and evolutionary roles in scorpion survival.

Reference:
Guo Y, Li S, Lu S, Wang X, Cao Z, Wu Y. Special Survival Strategy of First-Instar Scorpions Revealed by Synchronous Molting Behavior from Social Facilitation of Maternal Care and Reciprocal Aggregation. Insects. 2024;15(9). [Open Access]

Clustered setation on the pedipalps of buthid scorpions - morphology, taxonomic significance and a cleaning tool

 

The skin (exoskeleton) of scorpions has many different types of hairs (e.g. trichobothrias and setae). These have many functions, especially as sensory detectors of chemical substances and mechanical vibrations. For taxonomists they are also important morphological characters that can be used to identify taxa.

Trichobothriotaxy is already in great use in diagnosis  and description of many taxa (from species level to family level), but the usefulness of the setae (chaetotaxy) is less investigated. Graeme Lowe and Victoria Tang have now published a extensive study of chaetotaxy in scorpions with morphological descriptions of the different setation patterns in different taxa and the possible applications of these in taxonomy.

Interestingly, observations of Olivierus martensii (Karsch, 1879) (Buthidae) seem to indicate that this species uses setae clusters on pedipalps to brush the median ocelli (eyes) during sponge-bathing (cleaning behavior).

Abstract:
Chaetotaxy of the external pedipalp femur and distal ventral pedipalp movable finger was studied in 120 species, 69 genera and 17 families of scorpions. Setation was generally denser in the ‘Buthus’ group, a major arid-adapted buthid lineage distributed across Palearctic deserts. On the external femur, macrosetae formed a prominent cluster, the ‘distal external macrosetal cluster’ (DEMC); on the distal ventral movable finger they formed a dense patch, the ‘distal ventral macrosetal cluster’ (DVMC). In other buthids and non-buthids, the DEMC and DVMC were mostly absent, except in a few arid-adapted genera. Relative setation densities of DEMC and DVMC in different species depended strongly on size, being denser in larger species and sparser in smaller species, while absolute density varied only weakly with size (mean spacing of setae ~200 μm in DEMC, ~40 μm in DVMC). Ontogenetic variation followed similar trends. Multivariate morphometric analyses revealed taxonomic differences in setation patterns. The ‘Buthus’ group, other buthids, and non-buthids, were partially separable according to their spatial profiles of setation. In the ‘Buthus’ group, major genera were separable by spatial and density profiles of setation. In buthids, there were taxonomic differences in external femoral trichobothriotaxy. The ‘Buthus’ and Tityus’ groups were largely separable by proximodistal positioning of trichobothrium e1. Relative setation densities of DEMC and DVMC were positively correlated, in that species with dense DEMCs also tended to have dense DVMCs. In the buthid Olivierus martensii, DEMC and DVMC were observed to brush the median ocelli during sponge-bathing. In all examined buthids, the DEMC was located where it would contact the ipsilateral median ocellus during femoral articulation. Both DEMC and DVMC may assist in the ocular grooming of desert buthids, by removing sand and dust from surfaces of the median ocelli.

Reference:
Lowe G, Tang V. Clustered setation on the pedipalps of buthid scorpions (Scorpiones: Buthidae). Euscorpius. 2024(398):1-77. [Open Access]

Albinism in the buthid Olivierus martensii and review of albinism in scorpions in general

 

Albinism is known in many animals, but it is rare in scorpions. Victoria Tang and Zhenbang Liu has now published a very thorough article on this fascinating topic using albinism in Olivierus martensii (Karsch, 1879) (Buthidae) from China as an example.

The authors thoroughly describe and discuss all aspects of albinism in this species (origin of this phenotype, manifestation, and behavioral and ecological consequences of having this phenotype). Scorpion coloration in general is also discussed in relation to albinism.

Abstract:
This is a formal case report for the albinism in Olivierus martensii (Karsch, 1879). Albino phenotype is compared with its normal counterpart in terms of their morphology and behavior by cursory experiments. The examined 7 albino individuals (5 of which were adults) were smaller and more slender than their normal counterparts. However, these quantitative differences were not statistically significant and should be treated with caution due to the low sample size. Their abilities to detect both white light and UV light or UV-excited fluorescence were not significantly undermined, although their tendency to ensure a clear vision through self-cleaning behavior appeared to be reduced. Their heightened visibility on dark, leafmould substrate and greater crypticity on yellowish gravels may play a significant role in their natural survival. Additional evidence is required to substantiate this hypothesis as the function of scorpion coloration has been hardly studied. Several theoretical assumptions were proposed following a literature review on scorpion coloration and fluorescence, and this paper also serves as a brief synopsis of those aspects. Other three rare phenotypes in this species are also reported, defined here as piebaldism, hypomelanism and leucism. Given their existence, it is suggested that the loss of melanin in the epidermis beneath the ocelli is diagnostic for albinism in scorpions.

Reference:
Tang V, Liu Z. Albinism in Olivierus martensii (Karsch, 1879) (Scorpiones: Buthidae). Euscorpius. 2024(396):1-33. [Open Access]

An extensive revision of the genus Olivierus in Xinjiang, China

 

Victoria Tang a co-workers recently published a thorough revision of the genus Olivierus Farzanpay, 1987 (Buthidae) in Xinjiang, China.

Based on both morphological and molecular evidence, Olivierus longichelus (Sun & Zhu, 2010) and O. przewalskii (Birula, 1897) are the only representatives of this genus in this region. The authors also have made the following taxonomical conclusions:

Olivierus (Mesobuthus) bolensis (Sun et al., 2010) is synonymized with Olivierus longichelus (Sun & Zhu, 2010).

Olivierus (Mesobuthus) karshius (Sun & Sun, 2011) is synonymized with Olivierus longichelus (Sun & Zhu, 2010).

Olivierus tarabaevi Fet et al., 2021 is synonymized with Olivierus longichelus (Sun & Zhu, 2010).

Some information about the genus' habitat, distribution and biology is also included.

Abstract:
The genus Olivierus Farzanpay, 1987 in Xinjiang Uygur Autonomous Region, China, is revised based on recently collected topotypes and other populations from 12 localities. Brief differential diagnoses are provided, with colored illustrations and photos in vivo habitus, emphasizing the key characters. Chinese appellations, conservation status, and documentation of behavior and post-envenomation symptoms are also included. Only two species are now recognized for this genus in Xinjiang: O. longichelus (Sun & Zhu, 2010) and O. przewalskii (Birula, 1897), based on both morphological and molecular evidence. The two species exhibit extensive distribution in Xinjiang (China) while also occurring in adjacent countries. Three new synonyms are proposed: Mesobuthus bolensis Sun et al., 2010 = Olivierus longichelus (Sun & Zhu, 2010), syn. n.; Mesobuthus karshius Sun & Sun, 2011 = Olivierus longichelus (Sun & Zhu, 2010), syn. n.; Olivierus tarabaevi Fet et al., 2021 = Olivierus longichelus (Sun & Zhu, 2010), syn. n. Two species, Olivierus extremus (Werner, 1936) and O. hainanensis (Birula, 1904), are likely synonymous with O. martensii (Karsch, 1879). Should future examination confirm this assumption, the total number of species in genus Olivierus would be reduced to 16.

Reference:
Tang V, Liu Z, Graham MR, Fet V, Kovařík F, Šťáhlavský F. Revision of the genus Olivierus in Xinjiang, China, with comments on Mesobuthus thersites (Scorpiones: Buthidae). Euscorpius. 2024;2024(383):1-58. [Open Access]

Thanks to Victoria for informing me about the article and for sharing the illustration picture with us!

Family Buthidae

An updated checklist of scorpions of China with several taxonomic comments

 

Victoria Tang just published an updated checklist of scorpions of China. China has a large diversity when it comes to scorpions and the present article lists 52 species belonging to 13 genera and six families. 

Tang's article also discuss many taxonomic issues with several of the taxa reported from China. No taxonomical decisions are made, but the author recommend further investigations into many of the uncertainties. I refer to the abstract and the article for details on these.

Updated July 2022: My comment above that no taxonomical decisions were made in this article is not correct. The author made several taxonomic acts that can be seen in the abstract below. Thanks to Danniella Sherwood for commenting on this!

Abstract:
An updated checklist of scorpions of China (52 species belonging to 13 genera and six families) is provided, with Chinese name equivalents and an illustrated map of all localities. Colored photos of the Chinese population of Mesobuthus thersites (C. L. Koch, 1839) and one Olivierus sp. in vivo habitus are provided for the first time. The recent taxonomic changes are summarized. The monotypic genus Tibetiomachus (Hormuridae) with its single species T. himalayensis is considered a nomen dubium. The validity of the previously synonymized Scorpiops atomatus Qi et al., 2005 and S. validus (Di et al., 2010) (Scorpiopidae) is questioned, although they are not formally restored from synonymy. Olivierus hainanensis (Birula, 1904) (Buthidae) is possibly a junior synonym of O. martensii (Karsch, 1879); a reanalysis of the syntypes is warranted. The name “Scorpiops jingshanensis Li, 2016” is a nomen nudum. Additional comments are made upon two unavailable names that appear in an unpublished MS thesis (Zhang, 2009; in Chinese): “Mesobuthus beijiangensis” and “M. nanjiangensis”. A revision is needed of several species with weakly supported diagnostic characters, such as Olivierus bolensis (Sun et al., 2010) and Scorpiops puerensis (Di et al., 2010). The applicability of the diagnostic characters proposed for Olivierus bolensis (Sun et al., 2010) and O. longichelus (Sun & Zhu, 2010) is found to be unstable, based on the examination of some new specimens from Xinjiang. Their relationship with another two recently described species (O. mikhailovi Fet et al., 2021 and O. tarabaevi Fet et al., 2021), as well as the misidentified “Mesobuthus caucasicus intermedius” in China, remains unclear until a molecular study is accomplished.

Reference:
Tang V. Scorpions of China: an updated checklist with comments on some taxonomic issues (Arachnida: Scorpiones). Euscorpius. 2022(355):1-17. [Open Access]

Observations on regeneration of the pedipalp and legs of scorpions

 

Morphological anomalies in scorpions are well known. Some are inborne teratologies, others are caused becaused a failed molting process or due to accidents from predators attacs and similar. Scorpions can survive the loss of or damages to some of the appendages, but loss of the last part of the tail will usually cause death after a certain time as the anal organs are gone and the scorpion will die of constipation. 

Lost or damaged appendages can be reganerated completly or partly in scorpions during future molts. Martin Watz and Jason Dunlop have recently published a study on this topic and presented two cases of regeneration observed in scorpions in captivity relating to the pedipalp and legs. 

Abstract:
Two examples of scorpion limb regeneration following unsuccessful molts are documented based on material held in captivity. An Opisthacanthus asper (Peters, 1861) (Hormuridae) shows a relatively rare example of pedipalp regeneration in which the lost tibia and tarsus was replaced by a smaller, curved element of uncertain homology to either the fixed or free finger. A comparable abnormal palp described in the literature hints that pedipalps can only regenerate a structure of this form, regardless of the site of amputation. An Olivierus caucasicus (Nordmann, 1840) (Buthidae) is described in which claws (pretarsus) of leg III regenerated directly at the distal end of the tibia, while in leg IV the claws regenerated at the end of a truncated section of the metatarsus. This supports previous observations that scorpions can only regenerate the pretarsus of the leg, again irrespective of where on the limb the original breakage occurred.

Reference:
Watz M, Dunlop JA. Observations on regeneration of the pedipalp and legs of scorpions. Euscorpius. 2022(345):1-5. [Open Access]

Thanks to Martin Watz for sending me their article!

Three new species of Olivierus from Kazakhstan and Uzbekistan

 

Victor Fet and co-workers published this summer an article describing three new species of Olivierus Farzanpay, 1987 (Buthidae) from Kazakhstan and Uzbekistan. These species were previously classified as Olivierus gorelovi (Fet et al., 2018). The latter species is now restricted to Turkmenistan and southern Uzbekistan.

Oliverius mikhailovi Fet, Kovarik, Gantenbein & Graham, 2021 (Southern Kazakhstan, Uzbekistan)

Oliverius tarabaevi Fet, Kovarik, Gantenbein & Graham, 2021 (Kazakhstan)

Oliverius voldemari Fet, Kovarik, Gantenbein & Graham, 2021 (Uzbekistan)

The new species were discovered mainly due to genetic analysis. They are very cryptic and identification based on morphological characters is very difficult.

Abstract:
Following Graham et al. (2019), the recently described desert species Olivierus gorelovi (Fet et al., 2018) from Central Asia is herein restricted to Turkmenistan and southern Uzbekistan. In this contribution, we described other populations formerly included in O. gorelovi as three new species: O. mikhailovi sp. n. (southern Kazakhstan, Uzbekistan), O. tarabaevi sp. n. (Kazakhstan) and O. voldemari sp. n. (Uzbekistan: Ferghana Valley).

Reference:
Fet V, Kovak F, Gantenbein B, Graham MR. Three new species of Olivierus (Scorpiones: Buthidae) from Kazakhstan and Uzbekistan. Zootaxa. 2021;5006(1):54-72. [Subscription required for full text]

Thanks to Professor Fet for sending me their article!

Family Buthidae

A revision of the buthid genera Lychas, Mesobuthus, and Olivierus with several taxonomic changes

Frantisek Kovarik has published a revision of the genus-level taxonomy of Lychas C.L. Koch, 1845 (sensu lato) and Mesobuthus Vachon, 1950 (sensu lato) (Buthidae). This study presents the following taxonomical changes:

New genera:

Aegaeobuthus Kovarik, 2019 (4 species transferred from Mesobuthus Vachon, 1950).

Afrolychas Kovarik, 2019 (2 species transferred from Lychas C. L. Koch, 1845).

Janalychas Kovarik, 2019 (7 species transferred from Lychas C. L. Koch, 1845).

Spelaeolychas Kovarik, 2019 (1 species transferred from Lychas C. L. Koch, 1845).

See the Buthidae family page for information about which species that belongs to the different genera.

Olivierus Farzanpay, 1987 (Raised from synonymy with Mesobuthus. 18 species transferred from Mesobuthus. See the Buthidae family page for information about which species that belongs this genus).

Olivierus hainanensis (Birula, 1904) (Raised from synonymy and transferred from Mesobuthus).

New species:

Mesobuthus afghanus (Pocock, 1889) (Previous status M. eupeus afghanus Pocock, 1889).

Mesobuthus bogdoensis (Birula, 1896), (Previous status M. eupeus bogdoensis Birula, 1896).

Mesobuthus haarlovi Vachon, 1959, (Previous status M. eupeus haarlovi Vachon, 1959).

Mesobuthus iranus (Birula, 1917), (Previous status M. eupeus iranus Birula, 1917).

Mesobuthus mongolicus (Birula, 1912), (Previous status M. eupeus mongolicus Birula, 1912).

Mesobuthus persicus (Pocock, 1899), (Previous status M. eupeus persicus Pocock, 1899).

Mesobuthus thersites (C. L. Koch, 1839), (Previous status M. eupeus thersites C. L. Koch, 1839).

See article for more details.

Abstract:
The diagnostic characters are reassessed and defined for the genera Lychas C. L. Koch, 1845, Mesobuthus Vachon, 1950, and Olivierus Farzanpay, 1987 (the latter is restored from synonymy with Mesobuthus). Four new genera are described: Aegaeobuthus gen. n. (type species Buthus gibbosus Brullé, 1832), Afrolychas gen. n. (type species Isometrus burdoi Simon, 1882), Janalychas gen. n. (type species Lychas srilankensis Lourenço, 1997), and Spelaeolychas gen. n. (type species Isometrus hosei Pocock, 1891). Type species are designated for subgenera Lychas (Distotrichus) Tikader & Bastawade, 1983 (type species Isometrus nigristernis Pocock, 1899), Lychas (Alterotrichus) Tikader & Bastawade, 1983 (type species Scorpio mucronatus Fabricius, 1793), and Lychas (Endotrichus) Tikader & Bastawade, 1983 (type species Isometrus scaber Pocock, 1893). All these three subgenera are now in synonymy with Lychas C. L. Koch, 1845. Lychas kaimana Lourenço, 2011 is synonymized with Lychas shelfordi (Borelli, 1904). Taxonomic position of Lychas timorensis Lourenço, 2018, which is a member of Lychas variatus (Thorell, 1876) complex, is discussed. The species and subspecies of Mesobuthus Vachon, 1950 are discussed, with seven subspecies elevated to species level: Mesobuthus afghanus (Pocock, 1889), stat. n., M. bogdoensis (Birula, 1896), stat. n., M. haarlovi Vachon, 1959, stat. n., M. iranus (Birula, 1917), stat. n., M. mongolicus (Birula, 1912), stat. n., M. persicus (Pocock, 1899), stat. n., and M. thersites (C. L. Koch, 1839), stat. n. Taxonomic changes are supported by 182 figures including the first published photographs of the syntypes of Olivierus hainanensis (Birula, 1904), stat. n., comb. n. and O. przewalskii (Birula, 1897), comb. n.

Reference:
Kovarik F. Taxonomic reassessment of the genera Lychas, Mesobuthus, and Olivierus, with descriptions of four new genera (Scorpiones: Buthidae). Euscorpius. 2019(288):1-27. [Open Access]

Family Buthidae