First catalog of spiders of Egypt (Araneae)

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  First catalog of spiders of Egypt (Araneae) Abstract This study provides a comprehensive catalog of the spider fauna of Egypt, comprising 389 species assigned to 197 genera and 40 families. For each species, all published locality records are compiled and accompanied by complete bibliographic references. The dataset has been carefully reviewed and critically evaluated in light of the most recent taxonomic and faunistic information. Among the recorded species, 55 (14.13%) are currently known only from Egypt and are thus considered endemic. Based on the World Spider Catalog (2026), 28 species are treated as nomina dubia, 23 species lack confirmed records from Egypt, which is not correct, 10 have to be omitted from the Egyptian list and 8 are species inquirenda. Despite the relatively high number of documented species, the Egyptian araneofauna remains insufficiently explored. Given the country’s ecological diversity and biogeographical position, further research is expected to signi...

The Chemosensory Toolkit of a Cursorial Spider

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The Chemosensory Toolkit of a Cursorial Spider

Background

Chemosensation is vital for organisms to detect food, avoid predators, and find mates. Spiders, like many arthropods, rely on chemosensory input, but the modes and structures for detecting chemicals are not well understood. Cursorial spiders use chemical information for orientation and mate-finding. Behavioral studies suggest gustation plays a major role in male spiders following silken draglines to locate females, but the role of olfaction and tools involved in chemosensing are not known, despite the important ecological role of spiders.

Results

High-resolution electron microscopy revealed two types of chemosensory sensilla in the cursorial spider Pisaura mirabilis. Tip-pore sensilla, on the walking legs and pedipalps of both sexes, support contact chemoreception. Wall-pore sensilla, only occurring on adult male walking legs, are associated with olfaction. Behavioral assays confirmed that males detect airborne chemical signals from females, supporting these sensilla's role in mate search. The distribution of both sensilla types on walking legs is nearly complementary, with tip-pore sensilla towards leg tips and wall-pore sensilla towards leg bases supporting their respective contact and olfactory functions.

Conclusions

This study links the morphology, location, and function of chemosensory organs in cursorial spiders, providing insights into their chemosensory world. The findings advance the understanding of chemical sensing evolution in spiders and have implications for broader arthropod research. The identification of specialized olfactory sensilla in male spiders highlights the significance of airborne chemical detection in mate-finding, while contact chemoreceptors in both sexes suggest a general role in environmental chemical sensing.


Mohammad Belal Talukder, Carsten H. G. Müller, Andreas Fischer et al. The Chemosensory Toolkit of a Cursorial Spider, 18 March 2025, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-6228127/v1]