Behavioral evidence for two-stage sleep in spiders

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  Behavioral evidence for two-stage sleep in spiders Abstract Sleep is a fundamental behavioral state found across the animal kingdom, yet most of what we know about sleep is heavily vertebrate-biased. Studies are scarce or nonexistent in all but a few invertebrate lineages. A recent study of an REM sleep-like behavior in a jumping spider has reported unexpected parallels to sleep expression in vertebrates. So far, experimental evidence that these behavioral indicators truly represent sleep was lacking in spiders. Here, we present a comprehensive investigation into sleep behavior in the spider Portia fimbriata (Salticidae). We demonstrate diurnal activity, a free-running circadian rhythm, robust sleep architecture, regularly occurring REM-like behaviors, elevated arousal thresholds during those REM-like states, as well as rebound effects following sleep disruption. We conclude that the behavior we observe in spiders is behavioral sleep, providing evidence for an REM-like sleep sub...

A new species of Brotheas C. L. Koch, 1838 from Brazilian Amazonia (Scorpiones: Chactidae)

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A new species of Brotheas C. L. Koch, 1838 from Brazilian Amazonia (Scorpiones: Chactidae)

Abstract

A new species of scorpion, Brotheas pseudogranulatus sp. n. (Scorpiones: Chactidae), is described from the state of Amazonas in Brazil, near the border with Colombia. The new species is notably characterized by a strong granulation over the carapace and tergites, and appears as a possible vicariant element with Brotheas granulatus Simon, 1877, from the Guayana region of South America. The total number of Brotheas species is now raised to 31, of which 14 occur in the Amazon Basin, including 11 from the Brazilian Amazonia. The geographical distribution of the genus Brotheas is also enlarged.

Ythier E. & Lourenço W. R., 2026. – Une nouvelle espèce de Brotheas C. L. Koch, 1838 de l’Amazonie Brésilienne (Scorpiones: Chactidae). Faunitaxys, 14(30): 1 – 7. https://archive.org/details/faunitaxys-f-431