New species of crab has been found hiding in the seabed of Galicia (Spain)

During one of the expeditions of the research campaign INDEMARES that studies the Banco de Galicia underwater mountain, in August 2011 a team of scientists captured a new species of crab no bigger than 7 cm (including claws) at 1410 metres, within the least studied depths.

According to the study which has recently been published in the 'Zootaxa' journal, Uroptychus cartesi belongs to a family that is not diverse in the Atlantic Ocean. It is called the Chirostylidae family and is one of the mere four species that live in Europe. Three of them were discovered at the end of the 19th century and the fourth in 1976. Fourteen can be found in the Americas and more than 100 exist in the Indo-Pacific Ocean.

Despite their location in front of the coast of Galicia, this crustacean is unique to the easternmost part of the Atlantic due to the majority of its morphological characteristics: it is different from European species mainly because of its shape and the number of thorns on its shell. However, it has more similarities with the Caribbean species Uroptychus armatus.

"Its closeness to species from the Caribbean is logical. All North Atlantic species have common features and are likely to have come from shared ancestry, who invaded the Atlantic from the Pacific and Indian Ocean a few million years ago," as explained by Enrique Macpherson, coauthor of the study and researcher at the Centre for Advanced Studies of Blanes (CEAB-CSIC).

A very 'shy' crustacean

The small orange-coloured squat lobster usually lives around deep corals and gorgonians and "tends to be abundant in submarine mountains and canyons that have been subject to little fishing," explains Macpherson, who goes on to add that gorgonians and corals are the first to disappear in trawling zones.

Despite not bearing any resemblance, this squat lobster belongs to the group of hermit crabs. Researchers have verified that their larvae have a low dispersion capacity given that they "spend very few days in the planktonic stage." The study also points out that they usually feed on small crustaceans and particulate matter.

It takes the name of Uroptychus cartesi after the researcher Joan Cartes from Barcelona's Institute of Marine Sciences because of his "significant contribution to our knowledge of Iberian deep sea fauna." Macpherson and his colleague Keiji Baba from Kumamoto University (Japan) highlight that Cartes was also the first to recognise that individuals from this species were unusual.

The six specimens captured were handed over to Barcelona's Institute of Marine Sciences and the National Museum of Natural History in Paris, France.