Science Spotlight: New Spider Species Descriptions in Madagascar

It’s been a while but we are back with another new science spotlight blog, highlighting some more of the fantastic work done by our academic partners and students. In this edition, we showcase another set of brand new species descriptions – this time from our terrestrial Madagascar site. These new species are three jumping spiders (Salticidae) and two Orb-Weaver spiders (Araneidae).

Species discovery is an incredibly important part of global conservation efforts and a particularly exciting part of what we do here at Opwall. You can’t protect something if no-one knows it exists, right? We have discussed the importance and nuances of taxonomy for conservation in a previous blog post, which you can read about here. We had a particularly good year for species descriptions in 2024, describing a total of eight new species to science; this is the largest number of species descriptions we have ever had in a single  year and brings our overall total to 81! Naturally we are feeling quite proud of this and I thought it would be fun to highlight some of these discoveries, starting with these five new spiders.

Jumping spiders are the most diverse family of spiders in the world, with over 6600 species recorded. They are generally very small, ranging from 2 – 22mm and are often very strikingly coloured or patterned, as you can see from the picture below! Jumping spiders are named for their unique hunting style – pouncing or jumping on their prey. They are solitary nesting spiders and therefore don’t build webs, quite unlike the other new species described which are known for their large webs! Orb-weaver spiders don’t have quite as impressive diversity as the jumping spiders but with over 3100 described species they’re still a very big group! They vary a lot in size and some of the biggest species can even feed on bats!

Figure 1- Evarcha tsipikafotsy sp. nov. in vivo images, male. Photo credits: J.E.T. Sourced from Murray et al. (2024)

The authors; Katie Murray, Jaime Escobar-Toledo and Brogan Pett all work with the SpiDivERse working group of BINCO (Biodiversity inventory for Conservation). BINCO is an organisation founded with the aim of filling gaps in biodiversity knowledge, specifically with respect to smaller organisms that have been historically overlooked. Opwall are very excited to be partnered with them on a number of different projects. The SpiDivERse (Spider Diversity and Evolutionary Research) group within BINCO, directed by Dr Brogan Pett, focuses on spiders (Aranae) as they are one of the most fascinating and diverse groups of animals on the planet with around 50,000 described species (and perhaps more than twice as many undescribed species).

BINCO has been working at our Madagascar site for many years, and in 2023 SpiDivERse set up the first systematic inventory project ever completed in a Malagasy dry forest ecosystem. The core objective of the project is to create a clearer picture of how many species are actually present at the Mariarano research site. This is particularly important given Malagasy northern dry forests have incredibly high levels of micro-endemism (animals only found in incredibly small, niche environments) and it looks like there could be a very high number of undiscovered species within the Mariarano study area. This project is where the samples for these five new species were sourced, and there are many more where they came from, with four student-led papers currently in review. These samples are known as holotypes; a specimen designated by the original describer as the ‘type’ species, which is then stored and made available to future researchers who want to verify new specimens. These individual spider samples were painstakingly analysed and described in great detail to get ready for publication. If the discovery and describing of new species is interesting, check out our blog on species discovery here.

Figure 2 – Description images for Larinia mariaranoensis sp. nov.  Sourced from Escobar-Toledo & Pett (2024)

As you can imagine, an incredibly important part of describing new species is choosing the name. For a very long time it has been standard practice to use latin to describe the geography, ecology, or morphology of the new species in question. Historically, it has  also been common to see species named after the scientist who discovered them, or in honour of another scientist. However, this culture is starting to change, and there is now an increasing tendency to give species names in the local language of where they are found or to honour the local area or culture in some way, which is exactly what the authors have done here. Larinia mariaranoenisis is named after the area the holotype was discovered; Larinia foko is named for the Malagasy word for spider and the three jumping spiders are all named using Malagasy words to describe the species; for example Thyene volombavatanany means moustache (volombava) arm (tanany) in Malagasy, referencing the hairs on the underside of the legs.

The dry forests of north-western Madagascar are a globally important ecosystem which support huge numbers of endemic and micro-endemic species found nowhere else on the planet. The numbers of new species being described from our Mariarano study area shows just how much work there is to do in these ecosystems, and how important they are If you would like to be involved in our Madagascar project, have a look at our website here.

References

Escobar-Toledo J, Pett BL. 2024. Contributions to the Larinia-group (Araneae:Araneidae) in Madagascar, with the description of two new species. Contributions to the Larinia-group (Araneae: Araneidae) in Madagascar, with the description of two new species. Arachnology 19: 1312–1317.

Murray KI, Escobar-Toledo J, Pett BL (2024) Three new species of plexippine jumping spiders (Salticidae, Salticinae, Plexippini) from dry forest in Boeny region, north-western Madagascar. African Invertebrates 65(2): 61–74. https://doi.org/10.3897/AfrInvertebr.65.126810

Orb-Weavers – https://bugguide.net/node/view/1972

Jumping spiders – https://www.britannica.com/animal/jumping-spider