ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES)

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  ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES) Summary Scorpions are venomous animals with high plasticity and can serve as models for biogeographical, natural history, and evolutionary studies. Ecological niche modeling can help in understanding essential characteristics of the geographic distribution of species, as well as allowing the prediction of future distribution patterns. Our objective was to model the ecological niche of the scorpion species *Tityus serrulatus * and *Tityus stigmurus* , as well as to identify the variables that influence their distribution in different biomes and their range limits in the Amazon, Caatinga, and Cerrado biomes. Data were obtained from 12 Brazilian arachnological collections. Bioclimatic variables were obtained from the WorldClim database, and niche modeling was implemented using the Maximum Entropy algorithm. The results showed that the Atlantic Forest bio...

The tiniest violin: the male of Loxosceles vallenar (Araneae, Sicariidae)

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The tiniest violin: the male of Loxosceles vallenar (Araneae, Sicariidae)

Abstract

In recent years, several endemic species of Loxosceles, violin spiders, have been described from the North-Central Chile biodiversity hotspot, some of which have ambiguous placement within the species groups of the genus. In a recent expedition to the Atacama region, we collected male specimens representing new records of two recently described species: Loxosceles vicentei Taucare-Ríos, Brescovit & Villablanca, 2022 and Loxosceles vallenar Brescovit, Taucare-Ríos, Magalhaes & Santos, 2017 (Araneae, Sicariidae). Males of the latter are hitherto unknown and are here described for the first time. Examination of the morphology of these species revealed characters such as an embolic keel and digitiform median receptacles, which suggest they do not belong in the laeta species group, but rather in the spadicea species group, which is briefly re-diagnosed. With carapace lengths smaller than 2 mm, the newly discovered males of L. vallenar are the tiniest members of the genus. In addition, males of this species bear strong macrosetae in the clypeus, a sexually dimorphic character not previously reported in Loxosceles.

Magalhaes ILF, Iuri HA, Brescovit AD, Pizarro-Araya J (2024) The tiniest violin: the male of Loxosceles vallenar (Araneae, Sicariidae). ZooKeys 1206: 327-342. https://doi.org/10.3897/zookeys.1206.122469