A Turquoise Tarantula from Sri Lanka after 126 years | Sunday Observer

A Turquoise Tarantula from Sri Lanka after 126 years

15 September, 2019

A new species of ‘Chilobrachys’ (a genus of spider in the family Theraphosidae found in South and East Asia) emerges from a fragmented rainforest patch in Western Province Sri Lanka after 126 years. The species is named ‘Chilobrachys jonitriantisvansicklei’ in honour of the conservationist and co-founder of Idea Wild, a foundation supporting biodiversity research around the globe, Joni Triantis van Sickle for his tremendous backing on conducting research in fauna and flora around the globe by donating research equipment. This is the second Chilobrachys species discovered in Sri Lanka that belongs to the lot of 27 described species in the whole of the other regions in Asia. The discovery has been part of an ongoing island-wide study on the mygalomorph spiders in Sri Lanka.

These tarantulas are ground dwelling spiders living in burrows lined with silk and other debris. According to the BTS Journal, the specimens too were collected from burrows on a soil embankment covered with bryophytes, along the road with a clear tubular extension made up of soil and other debris.

In August 2012, Amila Prasanna Sumanapala, a postgraduate student at the Department of Zoology and Environmental Sciences, University of Colombo had first noticed a juvenile spider in a fragmented forest patch and recognized it as a ground tarantula species.

He had informed Ranil P. Nanayakkara, a postgraduate student at the Department of Zoology, University of Kelaniya and Co-Founder/ Principal Scientist, Biodiversity Education and Research. The latter was conducting an island-wide tarantula survey at that time. “On a later day, an adult spider was found at the same location and Ranil, who is the leading tarantula expert in Sri Lanka, recognized it to be a different species than what was known at the time from Sri Lanka,” Amila Sumanapala said.

Collaborative research

Amila and Ranil took up research on the species in collaboration with Peter Kirk, editor of the British Tarantula Society (BTS) Journal in 2015 probing into natural history, observing individuals and collecting specimens of two females and one male. The new species was compared with all previous material from Sri Lanka deposited at the national museum of Sri Lanka.

The collected specimen is quite different to that of the members of the same genus including Chilobrachys nitelinus backing up its taxonomy to be of a new species.

The BTS Journal 2019 Volume 34 No.2 illustrates, ‘interestingly, the majority of the known members of this genus are shades of brown, black or grey and lack vibrant colours or iridescent sheens’. The collected specimen also has a metallic turquoise-blue sheen on all four legs and an iridescent sheen on the carapace, abdomen and legs which deviates it from putative species of the genus.

Heretofore, from Sri Lanka there was only one species of the genus ‘Chilobrachys’ identified as, ‘Chilobrachys nitelinus’. Prominently, ‘Chilobrachys jonitriantisvansicklei’ runs counter to ‘Chilobrachys nitelinus’ from the colour of carapace, chelicerae, abdomen and legs where the Jonitriantisvansicklei has a turquoise-blue sheen on the above body parts whereas those of the Nitelinus are blackish.

They differ from each other in their reproductive structures as well.

Biodiversity hotspot

Providing insight into the fact that discovering a new species of animals is a not-talked-through stature, Sajeewa Chamikara, Director of Environmental Conservation explained that there are several other new species such as Amphibians, Reptiles, Press water crabs and Insects to be announced in different zones following the researches concluded recently.

He emphasized that Sri Lanka is a biodiversity hotspot and is noted for its bio-geographical importance. “For example, the Sinharaja Forest is one such hotspot. Its biodiversity is very rich. There are species called ‘Point Endemic Species’ in Sinharaja whose sole habitat is Sinharaja. So, if these hotspots are not conserved, Sri Lanka wouldn’t be ‘endemic’ to most of these species”.

He said that the urgent call to declare these forests and the habitats of these newly discovered species as protected areas still remains unheard and still not being considered primary. According to him, surveys on hunting down new species are seldom at university level.

“Even when these young researchers wish to conduct surveys, the Wildlife Department and the Forest Department are indisposed to cooperate with them and give them the approval to carry out their inspections,” he said. Owing to such biodiversity hotspots not being declared as protected areas, he stressed that between 1900 and 2000, 34 animal species have become extinct, 19 of them being from Sri Lanka.

Mygalomorph taxonomy has been out of the heed of Sri Lankan researchers in the recent years. Wanton killing by local villagers, unabated habitat destruction are the prominent pitfalls to the local populations of tarantulas found in Sri Lanka.

Apart from that, habitat loss due to development activities and encroachment for agricultural and settlement expansions, habitat fragmentation, illegal collection for pet trade and being killed by people out of fear are among the major threats to the tarantulas in the country.

In ensuring protection of new species and other mygalomorph spiders in Sri Lanka, comprisal of them in the Flora and Fauna Protection Ordinance of Sri Lanka and in the subsequent listing in CITES (The Convention on International Trade in Endangered Species of Wild Fauna and Flora) is of first magnitude.

The researchers Amila Prasanna Sumanapala and Ranil Nanayakkara are grateful to the Department of Wildlife Conservation, Biodiversity Secretariat of the Ministry of Mahaweli Development and Environment, Nagao Environment Foundation, International Society of Arachnology, IDEA WILD and their colleagues who supported them.