The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae)

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  The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae) Abstract The morphological characters of copulatory organs are the most important basis in spiders for identification. In theridiids, a vulva with four sac-like structures is mostly associated with the subfamily Hadrotarsinae but has never been recorded in Theridiinae. Based on specimens collected from subtropical forest canopies in China, a new Theridiinae genus that has four sac-like structures in the vulva is described: Sactheridion gen. nov., with the type species S. chuan gen. & sp. nov. from Sichuan Province, China. Photos, diagnosis, description, and a distribution map of the new genus and new species are provided. Hu, C., Yao, Z., Liu, J. & Xu, X. (2026) The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae). Zootaxa, 5884 (1), 167–175. http...

An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae)

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An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae)

Abstract

Mesobuthus Vachon, 1950, with 30 described species is widely distributed from the Eastern Mediterranean area to the Eastern Palaearctic. Mesobuthus rakhshanii Barahoei, 2022 is described from the north of Sistan & Baluchestan and southern parts of South Khorasan Provinces. Totally, 213 specimens of M. rakhshanii were collected from the various habitats of these regions during 2021 to 2023. Specimens were studied from morphological, molecular, biological, and ecological point of view. Bayesian inference (BI) analysis based on the COI gene was conducted. Thirty pairs of alive specimens were used for biological study. The maximum entropy model (MaxEnt) was utilized to evaluate the contribution rates of bio-climatic factors and to project suitable habitats for of M. rakhshanii. Unlike other Mesobuthus species, the central median and posterior median carinae of the carapace of M. rakhshanii are not connected. According to the BI, M. rakhshanii forms a sister group with M. navidpouri, indicating that they are the two youngest species within the genus. Mesobuthus mirshamsii was sequenced for the first time and the validity of this species was confirmed. The observed litter size for M. rakhshanii ranged from 22 to 36. Our findings indicate that annual precipitation and the mean temperature of the coldest quarter are the most influential variables affecting the potential distribution of this species. The estimated optimal distribution area for M. rakhshanii is approximately 943,578 km2, representing about 57.25% of Iran's land area. Among the suitable areas, 10.23%, 41.5%, and 5.52% were classified as low, moderate, and high suitability zones, respectively.

Barahoei, H., Madjdzadeh, S.M. & Moeinadini, A. An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae). Biologia 81, 112 (2026). https://doi.org/10.1007/s11756-026-02170-z