Three new spider species identified from Western Ghats of Karnataka

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Adding more to the endemic fauna of the Western Ghats, researchers have identified and described three new species of spiders from the Uttara Kannada district in the Indian state of Karnataka. 

Neoheterophrictus crurofulvus (Male)

Christened as Neoheterophrictus crurofulvus, N. sahyadri and N. uttarakannada, the newly identified spiders belong to a new genus Neoheterophrictus which is close to the existing Heterophrictus genus of spiders.

 

According to a research paper published in the Journal of Threatened Taxa, certain morphological and anatomical features which were consistent with the three species makes them different from other members of the Heterophrictus genus. 

The spiders in the new species have multi-lobed spermatheca (an organ in the reproductive tract in female spiders and other insects which usually stores the sperm from males to help fertilization), says the paper. 

Despite their close similarities with members of Heterophrictus and Plesiophrictus genuses, male spiders of new species have double tibial spur or two additional spines or segments at the distal end of their limbs than the members of closely related genuses. 

According to  Manju Siliwal, who was part of the research team, Stridulatory spines in these spiders are located on outer side of maxillae (small leg like structure in front of legs, where the basal segment is called maxillae) and inner side of coxa of first pair of leg. "So for sure, sound producing (by these spiders) might be different", she said.

The African Connection

The newly found genus also adds to the Gondwana relic taxa of the Peninsula. "The new genus belongs to the subfamily Eumenophorinae, which is restricted to Africa in distribution. So, finding a genus or species that is having ancestors in Africa are referred to be Gondwana relic", said the researcher.Presence of such connections supports the theory that India, Africa, Australia, South America and Antarctica were part of the super continent Gondwanaland which later broke apart to form the present continents.
 

Female of Neoheterophrictus sahyadri

Among the three, Neoheterophrictus crurofulvus was named so for the light brown legs of the female spiders. ‘Cruro’ in Latin means legs or limbs and ‘fulvus’  means tawny or yellowish-brown. While the males of the species were found under decaying logs and rocks, females were spotted in burrows. According to the researchers, the females of the newly identified spiders make 0.15 to 0.25 meters long silky vertical burrows of 15 to 25 mm diameter on slopes.


"We found many male individuals below decaying wooden log and found one wandering female, first", said a researcher of the team. However, the female spiders gave a tough task to the researchers. " On searching for five months we were able to locate more females because they don’t built typical theraphosid web", says the researchers. 

Neoheterophrictus sahyadri was named after the biodiversity hot spot and world heritage site Western Ghats from where it was found, since the mountain ranges are called ‘Sahyadri’ in local languages. 

Female of Neoheterophrictus uttarakannada

Females of the N. sahyadri makes burrows of 30 cm deep under decaying logs or rocks and hides in the burrow if the log is disturbed. According to researchers, they also tend to mark the borders of the resting place with mud. 

The third among the newly described spiders was named Neoheterophrictus uttarakannada after the district from which it was collected. The new discovery adds to the arachinid diversity of Western Ghats. 

The new addition to points to the unexplored nature of the rich biodiversity of Western Ghats. "It shows that these areas have still potential to find something new or interesting.", said Manju Siliwal who is a researcher with the Wildlife Information Liaison Development Society, Tamil Nadu. 

Neha Gupta, University School of Environmental Management, Guru Gobind Indraprastha University, and Robert Raven, Queensland Museum, Queensland, Australia have also co-authored the paper.