A new species of Opisthacanthus from Madagascar

 

Wilson Lourenco and co-workers have recently described a new species of Opisthacanthus Peters, 1861 (Hormuridae) from the Baie d’Antongil, located in the North-East portion of Madagascar.

Opisthacanthus antongil Lourenco, Wilme & Ythier, 2025

The distribution and biogeography of the genus is also discussed.

Abstract:
New comments are presented on the extraordinary diversity of the genus Opisthacanthus in Madagascar, with a similar number of species as in continental Africa, and a larger number of species than in Neotropical region. An African centre of origin can always be suggested for this group of scorpions, particularly in account of some associated Cretaceous fossil elements. The Gondwana model proposed equally suggests that the Madagascar Opisthacanthus could be closer to those of the New World, which is consistent with the affinities observed in morphological characters. A further new species, Opisthacanthus antongil sp. n., is described from the Baie d’Antongil, in a dense humid forest, located in the North-East portion of Madagascar. The new species shows particular affinities with Opisthacanthus piceus Lourenço & Goodman, 2006 known from the humid forests of the National Park of Andohahela, South of Vohibaka, located in the South-East portion of the island. The new species and O. piceus share similar external morphologies and in particular a blackish general coloration, with the exception of the telson’s coloration; however, the general chetotaxy is markedly different. The total number of species in Madagascar is now raised to 15. Hypotheses are also proposed about the species which inhabit humid formations in Madagascar.

Reference:
Lourenco WR, Wilme L, Ythier E. On the Malagasy species of Opisthacanthus peters, 1861 distributed in rainforest formations (Scorpiones: Hormuridae). Revista Iberica de Arachnologia. 2025(47):73–81. [Full text supplied by authors]

Family Hormuridae 

New study on taxonomy, distribution and habitat of the medical important genus Hemiscorpius in Iran

 

The genus Hemiscorpius Peters, 1861 (Hemiscorpiidae) is the probably the main scorpion taxa outside the family Buthidae that can cause death and serious morbidity in humans. This genus is represented with eight species in Iran and information about taxonomy, distribution and habitat preferences is very information to prevent sting cases.

Hossein Dehghan and co-workers have recently published a study on morphology, genetics, and ecological niche modeling to clarify the taxonomy and distribution of Hemiscorpius in southern Iran. The study also resulted in a new species from the Kerman Province.  

Hemiscorpius aratta Barahoei & Prendini, 2025

Abstract:
Eight species of the medically important scorpion genus Hemiscorpius Peters, 1861 have been reported in Iran, three of which are responsible for most of the severe clinical cases of envenomation. However, morphological similarity complicates species delimitation in this genus, hindering the identification of species implicated in envenomations. The present study integrates morphology, DNA sequences, and ecological niche modeling to clarify the taxonomy and distribution of Hemiscorpius in southern Iran, providing taxonomic insights relevant to public health and biodiversity conservation. Morphometric analyses were performed to evaluate size and shape differences; molecular phylogenetic analyses were conducted on DNA sequences of the mitochondrial Cytochrome c Oxidase Subunit I gene; and species distribution models, based on occurrence records and bioclimatic variables, were developed. Morphometric analyses revealed significant interspecific differences and sexual dimorphism. A new species was identified and described as Hemiscorpius aratta sp. n. Molecular phylogenetic analysis confirmed the distinctiveness of the new species and revealed intraspecific variation in the type species, Hemiscorpius lepturus Peters, 1861, suggesting possible cryptic diversity. Southern Iran, particularly the coastline of the Persian Gulf and the Gulf of Oman, represents a diversity hotspot for Hemiscorpius. Topographical barriers such as the Jebal Barez, Makkoran, and Zagros Mountain ranges promoted isolation and speciation, leading to high levels of endemism in the genus. Ecological niche models revealed that the distributions of Hemiscorpius species are strongly influenced by temperature and precipitation. Coastal species are restricted to thermally stable maritime habitats, whereas semi-arid species occupy regions with higher temperature seasonality. Range-restricted species are habitat specialists, vulnerable to environmental change. This study reinforces the importance of integrating morphological, molecular, and ecological data for resolving taxonomic ambiguity.

Reference:
Dehghan H, Amiri Ghanat Saman E, Madjdzadeh SM, Amiri M, Moeinadini A, Prendini L, et al. Molecules, Morphometrics and Modeling of the Medically Important Genus Hemiscorpius Peters, 1861 (Scorpiones: Hemiscorpiidae) in Iran Reveal New Species from Kerman. Insects. 2025;17(1):18. [Open Access]

Thanks to Gerard for informing me about this article!

Family Hemiscorpiidae 

 

A redescription of Centruroides infamatus and the description of a new species from Mexico

 

Happy New Year! 

Javier Ponce-Saavedra and co-workers recently published an article with a redescription of Centruroides infamatus (C.L. Koch, 1844) from Mexico. The study also identify a new species that previously were considered a population of this species from the municipality of Jalpa in the southern region of the state of Zacatecas, Mexico.

Centruroides rommeli Ponce-Saavedra, Linares-Guillen, Quijano-Ravell & Chassin-Noria, 2025

The article is in Spanish. 

Abstract:
Centruroides infamatus (C.L. Koch) is redescribed based on individuals obtained from a population from the León, Guanajuato region, in central Mexico. The species is redescribed because in the original description only the country is mentioned as the type locality with no further details. Also, Centruroides rommeli sp. nov. is described based on individuals obtained from a population of scorpions from Jalpa, municipality of Jalpa in the southern region of the state of Zacatecas, Mexico. This species is placed in the subgroup "infamatus" as part of the "striped" scorpions. Morphological comparisons are carried out with C. suffusus (Pocock) and C. vittatus (Say), both species that belong to the same subgroup talso recorded in Zacatecas. Additionally, is included the redescription of C. infamatus, because the population of the new species was previously identified with this specific name. Centruroides rommeli sp. nov. is sympatric with Mesomexovis spadix (Hoffmann), scorpions of the Vaejovidae family.

Reference:
Ponce J, Linares Guillén JW, Quijano-Ravell A, Chassin-Noria O. Redescription of Centruroides infamatus (Scorpiones: Buthidae) and description of a new species of “striped” scorpion of the “infamatus” subgroup from north-central México. Revista de la Sociedad Entomologica Argentina. 2025;84(4):e0409. [Full text supplied by authors]

Family Buthidae