Researchers from the Toralla Marine Science Station and the Spanish Institute of Oceanography (IEO) have just published a comprehensive study on the deep-water hermit crabs of Mauritania, in which a species previously unknown to science is described. This article, authored by researcher Susana S. de Matos-Pita and Professor Fran Ramil from the Department of Ecology and Animal Biology, was published in the journal Zootaxa and is part of the EcoAfrik Project. The new species has been named Paguristes candelae, and the researchers hope this will not be the last news regarding the discovery of new species in Mauritanian waters, as two more studies on crustacean biodiversity are also pending publication.
Twelve known species and one new one
The unexplored depths of the Mauritanian continental shelf are proving to be a source of new species for science. Ramil explains that they studied all the hermit crabs collected during the four Maurit oceanographic campaigns carried out in Mauritania from 2007 to 2010. “The study of all this material allowed us to identify 13 different species, and one of them, Paguristes candelae, turned out to be new to science, which we describe in this work, along with the other 12 that were already known.”
These species belong to the families Diogenidae, Paguridae, and Parapaguridae, and all were collected at 83 of the 316 trawl stations carried out on the deep shelf and continental slope of Mauritania during the aforementioned campaigns. The scientific article, over 40 pages long, includes extensive and carefully prepared iconography, much of it produced using a stereomicroscope and advanced image processing techniques.
The new species has been named Paguristes candelae, after Candela, the daughter of Susana S. de Matos-Pita, the researcher who described it and personally deposited its holotype at the National Museum of Natural Sciences in Madrid. Three specimens—a male and two females—were collected at three different stations along the continental slope of Mauritania, at depths ranging from 376 to 574 meters.
In addition to describing the new species, the publication also proposes the reclassification of two species into a different genus, provides the first description of the female of Paguristes marocanus, expands the geographic distribution of two species and the bathymetric range of three, and records three species for the first time in Mauritanian waters.
900 hermit crab species worldwide
Hermit crabs are well known and get their name from the habit of using the empty shells of various marine snails as their home, which are usually associated with different species. The most notable feature of these crabs, as Ramil explains, is that they have a soft, somewhat spiraled abdomen, which is why they live inside the empty shells of gastropods (snails) for protection. “This has the drawback that when they grow, they need to change their ‘home’ and find a larger one,” explains the researcher. There are also species that live associated with sponges and anthozoans (sea anemones and zoanthids), and in these cases, they do not need to change housing because the home grows with them.
The scientists Milne-Edwards and Bouvier were the first to describe the hermit crab fauna of West Africa in their works, published during the last decade of the 19th century. Today, around 900 different hermit crab species are known worldwide, and in fact, some of the species described in the recent Zootaxa publication had already been cited in Monod’s 1933 list of Mauritanian decapods. However, this is the first study to focus exclusively on the hermit crab fauna of the region, and without a doubt, the specimens collected during the Maurit campaigns constitute the most complete collection of these decapods ever obtained in this area. Fran Ramil emphasizes that the waters of Mauritania may host other hermit crab species beyond the 13 cited in the study and notes that, in fact, coastal species were not studied in this project “because we worked at depths ranging from 80 to 2000 meters.”
Source: DUVI
