New Publication: Hybridisation in the Tarantula Hobby

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  New Publication: Hybridisation in the Tarantula Hobby I am pleased to share the publication of my latest paper, “Hybridisation in the Tarantula Hobby: Ethical Boundaries and Biological Consequences,” in the Journal of the British Tarantula Society , Volume 41, No. 1, September 2026. The paper addresses an issue that deserves serious consideration within the tarantula community: hybridisation and its potential long-term effects on the integrity of captive lineages. More Than a Breeding Decision The tarantula hobby has changed considerably over the past several decades. What was once a relatively small community has grown into an international network of keepers, breeders, vendors, researchers, and societies. Captive breeding has contributed enormously to that growth, improving husbandry knowledge and increasing the availability of captive-bred animals. With that success comes responsibility for the lineages we maintain. Hybridisation may seem like an isolated breeding experiment,...

Copulatory mechanics in ghost spiders (Amaurobioidinae, Anyphaenidae) reveals an independent regressive evolution of a key genital trait through functional replacement

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Copulatory mechanics in ghost spiders (Amaurobioidinae, Anyphaenidae) reveals an independent regressive evolution of a key genital trait through functional replacement

Abstract

During evolution, the morphology of animal organs can vary drastically, such as the reduction or loss of structures. This phenomenon is recurrent in the male copulatory organs of many spiders, where structures that are usually well-developed, are missing or vestigial in some taxa. One example is the retrolateral tibial apophysis (RTA) of the male pedipalp of the most diverse lineage of spiders, the RTA clade. It frequently performs a key function during genital coupling, which is the first and main mechanical engagement during genital coupling (i.e., primary locking). However, in several lineages the RTA is either lost or reduced, raising questions on how genital coupling is achieved in these taxa, and what are the potential drivers for the regression of the RTA. To address these questions, we used the subfamily Amaurobioidinae (Anyphaenidae) as a model and studied the genital mechanics of nine species with different degrees of RTA size. Genital coupling was reconstructed using microcomputed tomography (micro-CT) data of cryofixed mating pairs, revealing that, except for a species with a prominent RTA, primary locking is solely achieved by inserting the conductor (a male genital sclerite) into one of the female copulatory openings. Our phylogenetic analyses indicate that the RTA has been independently lost or reduced six times in Amaurobioidinae, and that at least one functional replacement of the RTA by the conductor has occurred within the subfamily. We hypothesize that the use of the conductor for primary locking replaced the primary function of the RTA, allowing its repeated regressions.
Poy, D., Piacentini, L. N., Michalik, P., Lin, S., Martínez, L. A., & Ramírez, M. J. (2025). Copulatory mechanics in ghost spiders (Amaurobioidinae, Anyphaenidae) reveals an independent regressive evolution of a key genital trait through functional replacement. Arthropod Structure & Development, 86, 101442. https://doi.org/10.1016/j.asd.2025.101442