Researchers from various Spanish institutions, including the Doñana Biological Station (EBD-CSIC), have identified a new species of huntsman spider belonging to the genus Cebrennus in several areas of eastern Iberian Peninsula. This marks the first record of the genus—previously known only from Africa, the Middle East, and a few southern European islands—on the European mainland. The species, which exceeds one centimetre in body length, has been named Cebrennus herculis in honour of the mythological hero Hercules, evoking the separation of the African and European continents and symbolically mirroring the split of the Iberian lineage from its African relatives.

The discovery began with the capture of several Cebrennus specimens as part of a project aiming at assembling a checklist of arachnids in the coastal dunes of Valencia. Once identified, researchers confirmed the presence of six adult females and eleven juveniles. Later, another specimen was collected in a pitfall trap in the Hoya de Baza (Granada), and yet another was captured directly in Mediterranean scrubland in Nerpio (Albacete). All samples were preserved in absolute ethanol and stored in the Museu de Ciències Naturals de Barcelona.

Detailed morphological and genetic analyses confirmed that this was a species previously unknown to science. The research team compared three DNA markers (COI, 18S, and 28S) and placed C. herculis as a close relative of C. rungsi, the only African species with available genetic data. This suggests that the Iberian lineage could have diverged from an African one, following an ancient connection between the European and African continents.

Behavioural observations

Because the females and juveniles from Valencia were collected at different times of the year—both in spring and autumn—the team suggests that the species may have an extended breeding season or even multiple generations per year, though further research will be needed to confirm this.

While the juveniles were kept alive in small terrariums, some aspects of their behaviour were observed. They were observed building small burrows under the sand, covering the entrance with sand so that it blended seamlessly with the surroundings. At night, they would leave the burrow to wander around and then return. Six specimens were collected in low vegetation using a sweeping net, indicating that the species does not only inhabit the ground but can also move among low plants.

A hotspot of biodiversity

Thanks to its wide range of climates and habitats—from forests and scrubland to high mountain ecosystems and arid zones—the Iberian Peninsula harbours an exceptional diversity of spiders. Among them, more than 300 endemic species have been identified, and ongoing studies continue to reveal new species and shed light on their distribution and ecological significance.

The discovery of Cebrennus herculis shows that Mediterranean ecosystems still conceal remarkable and little-known biodiversity, and it opens the door to future research that could reveal even more undiscovered species in the Iberian Peninsula.

Scientific reference

Domènech, M., Calatayud-Mascarell, A., Pérez-Gómez, Á., Giacomelli, M., Iglesias Baquero, A., Mojica, M., Guerrero, J. J., Arnedo, M. A. & Lozano-Fernandez, J. (2025). Description of the first continental European species of the huntsman spider Cebrennus (Araneae, Sparassidae), confirming the presence of the genus in the region. Zoolgischer Anzeiger 318: 178-186. https://www.sciencedirect.com/science/article/pii/S0044523125000907