First color images and iNat entry for Isoxya penizoides

Congratulations to Ehoarn Bidault (@ehbidault) for posting the first iNaturalist record of Isoxya penizoides, a small, orange-tinged gasteracanthine of the Congo Basin -- an observation he made in Gabon last fall. This is not only the first observation we've found on iNaturalist but as far as I know, the first correctly identified color photographs of this species on the internet.

I was browsing photos of African orb-weavers on the Identify page, and this post caught my eye -- I didn't recognize the species, but it certainly looked gasteracanthine (which @begalma had also noted in a comment). @michael-gasteracantha recognized it right away. This species does not have prominent spines on its abdomen, and Michael speculates that perhaps it belongs better in the genus Aetrocantha, which is currently considered monotypic: Aetrocantha falkensteini.

French naturalist Eugène Simon illustrated the species in 1895 after initially describing it in 1887. A century later, Michel Emerit included a photograph of an adult female in his review of gasteracanthines housed in several European museums. These papers and others are available with a free World Spider Catalog account at this link: https://wsc.nmbe.ch/species/4189.

In a 1962 monograph on African gasteracanthines, Pierre L. G. Benoit wrote that this species is assumed to be fairly common in its range, which seems to be centered in the rainforests of the Congo Basin in western and central Africa. In his iNaturalist post, Ehoarn says that he found the spiders forming a colony several hundred strong.

Ehoarn has posted several really great observations of this group from across Africa; browse them all here: https://www.inaturalist.org/observations?place_id=any&subview=grid&taxon_id=1004909&user_id=ehbidault&verifiable=any.

Keep those new and interesting observations coming, everyone!

FYI @zarek @wynand_uys @botanicaltreasures @htct @jakob @tiwane

Posted on February 9, 2021 11:21 PM by djringer