Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain

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  Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain Abstract A taxonomic revision of the species of Nemesia Audouin, 1826, distributed in the vicinity of Córdoba City, southern Spain, is presented. Four new species are described: Nemesia morana sp. nov. (female), N. kodama sp. nov. (male and female), N. rosae sp. nov. (male and female), and N. tamajoni sp. nov. (male and female). These species are distinguished by distinct morphological characters, including the shape of the spermathecae, palpal bulbs, and spinnerets, as well as by burrow architecture. Fieldwork was conducted across two of the three major habitat types in the region—the humid, forested mountains of Sierra Morena and the croplands and riparian forests of the Guadalquivir Valley—while the third, the “campiña”, which is mainly composed of agricultural landscapes, remains poorly explored. Sampling methods included pitfall trapping and the direct e...

Oscillating in darkness: Circadian rhythms of cave-dwelling scorpions

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Oscillating in darkness: Circadian rhythms of cave-dwelling scorpions

ABSTRACT

Circadian rhythms, typically synchronized with light–dark cycles, regulate key biological processes in surface organisms. In caves, however, the absence of light may disrupt these rhythms or promote alternative temporal patterns. We examined locomotor activity in two cave-dwelling scorpions with contrasting degrees of subterranean adaptation: Troglorhopalurus translucidus (troglobitic) and Troglorhopalurus lacrau (troglophilic). Activity was monitored under constant darkness (DD), light–dark (LD), and constant light (LL). Both species retained circadian rhythmicity, but with distinct responses: T. translucidus and T. lacrau exhibited diurnal activity under LD and changes in period under DD and LL. These findings demonstrate that circadian regulation persists in cave-adapted scorpions, but its expression is shaped by evolutionary pressures, highlighting the plasticity of biological clocks in light-deprived environments.

de Souza, P. E., & Ferreira, R. L. (2025). Oscillating in darkness: Circadian rhythms of cave-dwelling scorpions. Chronobiology International, 1–8. https://doi.org/10.1080/07420528.2025.2596773