Tomocyrba is a genus of jumping spiders in the family Salticidae, subfamily Hisponinae, endemic to Madagascar. It was first described by the famed French arachnologist Eugène Simon in 1900, based on specimens collected near Antongil in northeastern Madagascar. Despite its early recognition, the genus has received remarkably little taxonomic attention since then. In fact, until now, only a single contribution to its taxonomy had been made in the last 120 years: a 2009 revision by Tamás Szűts and Nikolaj Scharff, which expanded the genus to six species, four of which were newly described at that time. All previously known material was based on historic type specimens more than a century old, leaving researchers with little understanding of the spiders’ ecology, variation, or true diversity.

The new study stems from two recent expeditions to northern Madagascar organized by the Biodiversity Inventory for Conservation (BINCO) and collaborators. One expedition targeted the Mahimborondro protected area in the far north of the island, while the other explored Makira Natural Park near the town of Maroantsetra, close to Antongil Bay. These surveys yielded a small but scientifically precious collection of adult Tomocyrba specimens, allowing lead author Brogan L. Pett to describe one species new to science and to provide a supplementary redescription of the type species, Tomocyrba decollata Simon, 1900, based on the first newly collected material in over a century.

The new species, named Tomocyrba ankihiberta sp. nov., was found in the Mahimborondro protected area at an elevation of 1,500 meters in tropical rainforest. The name derives from the Malagasy word ankihibe, meaning thumb, combined with RTA, the abbreviation for retrolateral tibial apophysis, a key anatomical feature of the male pedipalp. This thumb-like structure is one of the distinctive traits that sets the new species apart from its relatives. Both a male holotype and a female paratype were collected between late January and mid-February 2019 and are now deposited in the Royal Museum for Central Africa in Tervuren, Belgium.

Diagnosing a new spider species relies heavily on the intricate architecture of reproductive structures, which are often species-specific and act like evolutionary fingerprints. In male T. ankihiberta, the embolus, the slender sperm-transferring structure at the tip of the pedipalp, is barbed, slightly bent, and tapers to a sharp point, projecting prolaterally along its entire length. This distinguishes it most clearly from its closest relative, T. barbata, whose embolus is curved retrolaterally in its basal half, broad, and lacks a tapered point. The retrolateral tibial apophysis in the new species is short, rounded, and thumb-like, whereas in T. barbata it projects a short distance before curving back toward the palp with a thin sharp point. Females of the new species share long, mostly straight copulatory ducts with T. berniae, but differ in having two copulatory openings rather than one, and in possessing paddle-shaped, chambered spermathecal walls rather than undulating, tube-like ones.

The rediscovery of Tomocyrba decollata is equally significant. The species was originally described from specimens collected at Antongil, likely corresponding to the port city of Maroantsetra adjacent to Antongil Bay. The 2009 redescription relied on syntype material more than 120 years old, with specimens so bleached that the female’s internal genitalia could only be examined by temporarily clearing the abdomen with methyl salicylate, a technique that left the vulva unprepared for detailed study. The new material, consisting of two males and one female collected in Makira Natural Park in September 2023, represents the first records of this species in 120 years and provides the first-ever illustration of the internal structure of the female epigyne. Remarkably, the new collection site lies possibly only around 30 kilometers from the original type locality.

The fresh specimens allowed for a thorough redescription of T. decollata, revealing details that had been obscured by the degraded condition of the historic types. Males are easily recognized by a very short, undulating embolus and a broad, evenly rounded retrolateral tibial apophysis. Females are distinguished by an epigyne that is much broader than long, with short copulatory ducts running posteriorly from the copulatory openings. The redescription also documented previously unrecorded details, including the arrangement of teeth on the chelicerae: the promargin bears nine teeth, with the distal two and the second from the base much larger than the others, while teeth three through five are reduced to small denticles. The retromargin carries a single comb-like tooth with seven small denticles in males and eight in females.

Understanding where Tomocyrba sits on the spider family tree adds another layer of intrigue. The subfamily Hisponinae, to which the genus belongs, is well supported by both molecular and morphological evidence. It is diagnosed by a distinctive constriction in the carapace just behind the posterior median eyes, first noticed by Simon in 1901, along with a first metatarsus bearing no more than one pair of spines. More recently, researchers discovered that hisponines possess dual copulatory ducts in the epigyne, a trait that appears to be a shared derived feature of the subfamily. Phylogenetically, hisponines are enigmatic: they sit as the sister group to the Salticinae, the subfamily that dominates jumping spider diversity across the globe, yet they are relatively common in Baltic Amber fossils, suggesting a much wider historical distribution than their current, largely restricted range.

The fieldwork methods behind the discovery highlight the practical challenges of documenting rare arthropods in tropical forests. Mahimborondro specimens were collected opportunistically using small plastic pots filled with diluted ethanol, while Makira specimens were obtained through dedicated active searches on shrubbery and leaf litter, or with beating sheets. In the laboratory, male pedipalps and female epigynes were carefully dissected and cleared in warm potassium hydroxide solution before examination under compound and stereo microscopes. High-resolution habitus and genitalia images were captured using digital imaging systems and z-stacked photomontage software, producing the detailed figures that accompany the taxonomic descriptions.

Madagascar is renowned as a global biodiversity hotspot, with an extraordinary proportion of its flora and fauna found nowhere else on Earth. Yet its rainforests continue to face intense pressure from deforestation, fragmentation, and climate change. The fact that a genus as distinctive as Tomocyrba went essentially unstudied for 120 years, and that its type species could be rediscovered just tens of kilometers from where it was first collected, speaks both to the resilience of these forest ecosystems and to how much remains undocumented. Each new species description and each rediscovery strengthens the case for protecting Madagascar’s remaining rainforest corridors, not only for charismatic vertebrates but for the countless small, cryptic organisms that make up the bulk of the island’s evolutionary heritage. For now, T. ankihiberta joins the ranks of Madagascar’s endemic jumping spiders, and T. decollata emerges from more than a century of obscurity with its anatomy finally brought into sharp, modern focus.

Subject of Research: Taxonomy and rediscovery of jumping spiders in the genus Tomocyrba from northern Madagascan rainforests

Article Title: Discovery of a new Tomocyrba ( Araneae , Salticidae , Hisponinae ) and rediscovery of the type species from rainforests in northern Madagascar

Article References: Pett, B. L., & Murray, K. I. (2026). Discovery of a new Tomocyrba (Araneae, Salticidae, Hisponinae) and rediscovery of the type species from rainforests in northern Madagascar. African Invertebrates, 67(1), 37-46. https://doi.org/10.3897/afrinvertebr.67.183477

Image Credits: AI Generated

DOI: 10.3897/AfrInvertebr.67.183477

Keywords: Tomocyrba, Salticidae, Hisponinae, Madagascar, jumping spiders, new species, taxonomy, rainforest, biodiversity, rediscovery, Mahimborondro, Makira