Sexual dimorphism in Uroplectes lineatus and a tool for testing specific hypotheses of sex differences in scorpions

 
Striped Lesser-thicktail Scorpion Uroplectes lineatus. Photo: John Visser (C). Used with permission.

As with many other animals, scorpions also shows sexual dimorphism to a greater or lesser degree. The reasons why we see these somtimes large differences between the sexes are less understood. Jacobus Visser and Sjirk Geerts has used the method static allometry to investigate sexual dimorphism in Uroplectes lineatus C. L. Koch, 1844 (Buthidae).

The results indicate that the sex differences in males may have a function during courtship, while the differences seen in females may have a postive effects on reproduction and parental care. It is important to note that the forces that shapes scorpion morphology are complex and studies of more species are necessary to learn more about the evolution of sexual dimorphism in scorpions.

Abstract:
Scorpions exhibit extreme forms of sexual dimorphism, with a number of recent studies highlighting general patterns. Explanations surrounding the potential drivers of these patterns remain speculative, even though static allometry offers a method for testing specific hypotheses. Importantly, a recent study describes a method of reference character choice when investigating sexual dimorphism and static allometry in scorpions. Here, commonly measured morphometric characters are used to investigate patterns of sexual dimorphism and static allometry in the South African scorpion Uroplectes lineatus C. L. Koch, 1844. Several analyses were used to select telson length as the sexually neutral reference character. Sexual body component dimorphism characterises U. lineatus males, while females generally display sexual size dimorphism. Similar patterns of static allometry characterise both sexes, with negative allometry retrieved for most characters, while three characters display positive allometry. For negatively allometry characters, inter-sexual selection likely favours a standard size of body parts in the population to facilitate inter-sexual interaction during courtship. In contrast, positively allometric characters may be under intrasexual selection, following the utility of features during contests. Even so, the differences in allometric slopes between the sexes indicate the possible functions of male features during courtship, while the female morphology is adapted to enhance reproductive output and parental care. Here, we demonstrate that a set of verification analyses may be effective in choosing an appropriate neutral reference character, but the selective forces which shape scorpion morphology are complex, and standardized methods need to be established to allow for robust inferences and inter-study comparability.

Reference:
Visser JH, Geerts S. Static allometry and sexual dimorphism in the Striped Lesser-thicktail Scorpion Uroplectes lineatus. Arachnology. 2021;18(7):700-7. [Subscription required for full text]

David Gaban - RIP

 I got the sad news this morning from multiple postings on Facebook that David (Dave) Gaban is no longer among us. Most, if not all of us in the scorpion community knew Dave. Either by personal communication or from his numerous contributions in different fora on the internet and in ATS publications like "Gaban's Scorpion Tales" from 1998. He also published some scientific work like the article "Ecdysis in scorpions: Supine behavior and exuvial ultrastructure" which he co-authored together with professor Roger Farley in 2005.

Dave was a major source of knowledge and always interested in sharing this knowledge with the rest of us. He was one of my first international contacts when I started participating in the old "Scorpion Enthusiast email list" almost 30 years ago. He always answered my emails even though I suspect that I was not the only one sending him questions. I will always be grateful for this!

Dave was also a good photographer and started early taking pictures of his scorpions. And when I started The Scorpion Files, Dave was more than willing to allow me using his pictures in my new web site. There are more than 40 of his pictures in the gallery today.

My thought are with Dave's family.

RIP

Jan Ove Rein
Editor of The Scorpion Files

Updated identification on a few scorpions in a museum collection

 

There are a lot of scorpions in museum- and university collections around the world. Many of these were collected and identified decades and even centuries ago. In the meantime, scorpion taxonomy has been revised and updated and I guess a lot of the specimens in these collections may have both new status and names.

Ersen Yagmur has recently examined several specimens of Euscorpiidae collected by R. Kinzelbach in Turkey in the 1970s and deposited in the Naturhistorisches Museum Mainz (NMM), Germany and updated their identification.

Abstract:
I examined the specimens of Euscorpiidae collected by R. Kinzelbach in Turkey in the 1970s and deposited in the Naturhistorisches Museum Mainz (NMM), Germany. According to the current taxonomy, one “Euscorpius carpathicus” specimen from the İzmir Province is identified as E. avcii; two “E. carpathicus” specimens from the Mersin Province are identified as E. koci; and one “E. germanus mingrelicus” specimen from the Düzce Province is identified as Alpiscorpius phrygius.

Reference:
Yagmur EA. On R. Kinzelbach‘s euscorpiid specimens from Turkey deposited in the Naturhistorisches Museum Mainz, Germany (Scorpiones: Euscorpiidae). Euscorpius. 2021(334):1-5. [Open Access]

Family Euscorpiidae

New knowledge on the rare scorpion Cryptoiclus rodriguezi from Cuba

 

Rolando Teruel has just published an article with new information on the rare, endemic scorpion Cryptoiclus rodriguezi Teruel & Kovarik, 2012 (Diplocentridae) from Cuba. Updated morphological descriptions and data on distribution, habitat, ecology and reproduction are presented.

Abstract:
The adult male of Cryptoiclus rodriguezi Teruel & Kovarik, 2012, is herein described and illustrated in detail. It represents both the single species of its genus and one of the most seldom-collected , endemic scorpions from Cuba. Its generic diagnosis is emended and new data on its morphological, morphometric and meristic variability are contributed on the basis of the type and 28 additional specimens. Abundant information on its ecology and reproduction are given and its geographic distribution is updated with new records, including the first from Maisi municipality. Despite this, both the genus and the species remain known only from a reduced area in northeastern Guantanamo Province.

Reference:
Teruel R, Rodriguez-Cabrera TM. La subfamila Diplocentrinae (Scorpiones: Diplocentridae) en Cuba. Septima parte: complementos a la descripcion de Cryptoiclus rodriguezi Teruel & Kovarik, 2012. Boletin de Grupo de Sistematica y Ecologia de Artropodos Caribeños. 2021(8):1-23.

Thanks to Rolando for sending me his article!

Family Diplocentridae

First record of Euscorpius lesbiacus from in Turkey

 

 The recently described species Euscorpius lesbiacus Tropea et al., 2020 (Euscorpiidae) from the Greek island Lesvos has now been discovered in Turkey by Ersen Yagmur.

Abstract:
The scorpion species Euscorpius lesbiacus Tropea et al., 2020, previously known only from Lesvos Island (Greece), is recorded for the first time from the İzmir Province, Turkey. Detailed illustrations of E. lesbiacus are given.

Reference:
Yagmur EA. The first record of Euscorpius lesbiacus Tropea et al., 2020 (Scorpiones: Euscorpiidae) in Turkey. Euscorpius. 2021(333):1-5. [Open Access]

Family Euscorpiidae

A phylogentic analysis of the genus Buthacus

 

A few weeks ago a reported about a  a systematic revision of the Buthacus Birula, 1908 (Buthidae) species of the Levant (the Middle East including Syria, Lebanon, Jordan, Israel, the Palestinian territories, and the Sinai Peninsula (Egypt)). 

The same authors have now published a study on the phylogeny and biogeography of the genus Buthacus resulting in a revised classification of Levantine Buthacus, and invalidation of the traditional species groups of Buthacus.

Abstract:
Sand scorpions of the genus Buthacus Birula, 1908 (Buthidae C.L. Koch, 1837) are widespread in the sandy deserts of the Palearctic region, occurring from the Atlantic coast of West Africa across the Sahara, and throughout the Middle East to Central Asia. The limits of Buthacus, its two species groups, and many of its species remain unclear, and in need of revision using modern systematic methods. The study presented here set out to investigate the phylogeny and biogeography of the Buthacus species occurring in the Levant, last studied in 1980. A phylogenetic analysis was performed on 104 terminals, including six species collected from more than thirty localities in Israel and other countries in the region. Three mitochondrial and two nuclear gene loci were sequenced for a total of 2,218 aligned base-pairs. Morphological datasets comprising 22 qualitative and 48 quantitative morphological characters were compiled. Molecular and morphological datasets were analyzed separately and simultaneously with Bayesian Inference, Maximum Likelihood, and parsimony. Divergence time and ancestral range estimation analyses were performed, to understand dispersal and diversification. The results support a revised classification of Levantine Buthacus, and invalidate the traditional species groups of Buthacus, instead recovering two geographically-delimited clades, an African clade and an Asian clade, approximately separated by the Jordan Valley (the Jordan Rift Valley or Syro- African Depression), the northernmost part of the Great Rift Valley. The divergence between these clades occurred in the Early Miocene (ca. 19 Ma) in the Levant, coinciding temporally with he existence of two land bridges, which allowed faunal exchange between Africa and Asia.

Reference:
Cain S, Loria SF, Ben-Shlomo R, Prendini L and Gefen E. Dated phylogeny and ancestral range estimation of sand scorpions (Buthidae: Buthacus) reveal Early Miocene divergence across land bridges connecting Africa and Asia. Mol Phylogenet Evol. 2021:107212. [Subscription required for full text]

Family Buthidae