A team of Brazilian arachnologists has described a new species of cave-dwelling harvestman in the genus Iandumoema, bringing the total number of species in the genus to three.

The team, headed by Dr Ricardo Pinto-da-Rocha of the Instituto de Biociências da Universidade de São Paulo, named the new species Iandumoema smeagol after the ‘Lord of the Rings’ character Smeagol.

“The species name refers to the hobbit named Smeagol, created by J.R.R. Tolkien, being the original name of Gollum – the dweller of the caves located below the Misty Mountains of Middle-earth of the Lord of the Rings book,” Dr Pinto-da-Rocha and co-authors wrote in a paper in the journal ZooKeys.

Two other extant species of the genus Iandumoema are I. uai and I. setimapocu.

According to the arachnologists, the newfound species is the most highly modified in the genus and only the second cave-dwelling harvestman with no eyes for Brazil. It also has a reduced amount of melanistic pigmentation, which shows through its pale yellowish colors.

“The species is recorded from two caves – Toca do Geraldo and Lapa do Santo Antonio – in Monjolos region, the Brazilian state of Minas Gerais,” the scientists said.

“This region is located in the central east part of the southern portion of the São Francisco Craton, Velhas river basin, with a mean altitude of approximately 600 m (1,970 feet), inserted in the Sete Lagoas Formation, Bambui Group, which has a relief typical of karst carbonate regions.”

While there are cave-dwelling harvestmen that can survive above the ground and even regularly go out in order to feed or mate, there are some, such as Iandumoema smeagol, that never leave their underground habitats.

A total of 14 individuals of the new species were observed by the scientists.

“The harvestmen were found on the wet walls and sometimes in the silt substrate, next to the drainage, always in the aphotic zone,” they said.

“While the juveniles appeared quite active, the adults showed a more sedentary behavior.”

Typically for the harvestmen (order Opiliones), Iandumoema smeagol was found in a cave with organic matter deposits or spots.

On one occasion the scientists observed one of the individuals in such litter, where it was scavenging carcasses of invertebrates.

_____

Ricardo Pinto-da-Rocha et al. 2015. A new highly specialized cave harvestman from Brazil and the first blind species of the genus: Iandumoema smeagol sp. n. (Arachnida, Opiliones, Gonyleptidae). ZooKeys 537: 79-95; doi: 10.3897/zookeys.537.6073