Mumbai: Researchers have recently documented the presence of a new species of spider in the Thar Desert National Park Wildlife Sanctuary in Rajasthan, in addition to a new record of a species for the first time in India.

The species are Pseudomogrus sudhii, named after the famous Indian zoologist AV Sudhikumar, which is a newly described species, and Plexippus minor, which was previously seen only in two places in the desert landscape of the United Arab Emirates (UAE ).

Both species belong to a larger family of ‘jumping spiders’ called ‘salticidae’. Scholars from Christ College, Kerala; Indian Wildlife Institute (WII), Dehradun; The University of Manchester and the Royal Museum for Central Africa published the findings last week in the peer-reviewed international journal Arachnology.

According to the existing literature, the family Salticidae contains over 600 different genera (a category that ranks above species and below family) and over 6,000 described species of spiders, several of which can be found across country, and others are still being discovered. Spiders are called salticidae because instead of trapping prey in a web, they stalk and chase prey by jumping on it.

In 2021, at least three new records of jumping spiders have been recorded in Maharashtra alone, including the species Icius tukarami (named after Tukaram Omble, the police officer who lost his life trying to fend off Ajmal Kasab during the terrorist attacks of 26/11) of Thane-Kalyan and Phintella cholkei, from the Aarey colony of Mumbai, named after the late naturalist Kamlesh Cholkhe. A third species, Irura mandarina, was reported for the first time in India, in the Western Ghats, in the Kudal taluka of the district of Sindhudurg. In the Thar Desert, the first record of another species of jumping spider, Menemerus marginatus, was also made in 2021.

Rishikesh Tripathi, who led the research effort to taxonomically describe Irura mandarina, is one of the researchers behind the recent discoveries in the Thar Desert.

Of the two spiders, Pseudomogrus sudhii is an entirely new species, belonging to the genus Pseudomogrus which was first described in 1937 and includes 34 described species of spiders distributed in the Canary Islands, the Mediterranean, southern Europe, North Africa, western Mongolia and western China.

“To date, no Pseudomogrus species from Afghanistan, Pakistan or India have been recorded or described. Our discovery is the 35th species recorded globally and the first in India,” Tripathi said.

Pseudomogrus sudhii has been found in the dry and arid grasslands of the Thar, and researchers have reason to believe that it is likely that this species may also occur in the Cholistan Desert in Pakistan, which represents the northwestern limit of the Thar Desert. “The salicidal faunas of Afghanistan and Pakistan, which should undoubtedly contain species of Pseudomogrus (but not yet recorded), remain poorly studied,” note the researchers.

The second discovery, of Plexippus minor from the same geographic region, marks the first sighting of a species previously seen otherwise only at two locations in the Middle East. It belongs to the genus Plexippus, first described in 1846 and which includes 45 species described to date. Of these, six have already been found in India.

These findings show strong similarities between the fauna of the Palearctic and Eastern zoogeographical regions. The first includes Europe, the region of Asia north of the Himalayas and Africa north of the Sahara. The latter includes India, Pakistan, Sri Lanka, Bangladesh, Nepal, Bhutan and Burma, Indochina and southern China.

“Although the regions are biologically distinct, finds of similar species show that there is a biogeographic continuum between them,” Tripathi said.

“For example, most species closely related to P. sudhii are known either from the Near East or from the southern Mediterranean and Saudi Arabia. Thus, the presence of a species of Pseudomogrus in the Thar Desert suggests a connection in the spider fauna of the region with others in the southern Palearctic. This is hardly surprising as the Thar lies in the transition zone between the Palearctic and Eastern regions,” Tripathi added.

Similarly, the presence of Plexippus minor in the Thar also demonstrates a similar relationship between the two regions. “It is possible that the Thar region, which is a juxtaposition of environmental conditions found in the Palearctic, Eastern and Saharan regions, harbors a wide range of undiscovered taxa that share a biogeographical relationship across the Middle East and the Indian Desert. of the Thar,” said Tripathi.