- Sri Lanka has yielded up four new species of Asian jumping spiders, the first time spiders from the genus Synagelides have been recorded on the biodiversity-rich Indian Ocean island.
- The new species, cryptic small spiders that live in association with ants, have been named Synagelides hortonensis, S. lakmalii, S. rosalindae and S. orlandoi.
- The latter two are named after Rosalind Senior and Orlando de Bois, a pair of lovers in the Shakespeare comedy “As You Like It”; S. hortonensis is named after Horton Plains National Park, from where the type specimen was described; and S. lakmalii after scientist U.G. Sasanka Lakmali Ranasinghe.
COLOMBO — Sri Lankan researchers have described the first ever species of jumping spiders from the genus Synagelides that are native to the Indian Ocean island, identifying not one but four of the arachnids.
In a paper published in the journal Zootaxa, they name the new species Synagelides hortonensis, S. lakmalii, S. rosalindae and S. orlandoi — the latter two named after the lovers in William Shakespeare’s popular comedy As You Like It.
Entomologist Suresh P. Benjamin, a co-author of the new study, told Mongabay these are the first species from the genus described from Sri Lanka, and likely not the last. “There is a lot to study in Sri Lanka,” he said.
With more than 6,000 species described worldwide, jumping spiders (family: Salticidae) are the largest known spider family.
The recent publication is a part of an ongoing effort to study the endemic arachnids of Sri Lanka, a biodiversity haven best known for its dazzling variety of reptile life. The new discovery brings to 31 the known species of jumping spiders described from Sri Lanka.
“The current initiative aims to place the island’s jumping spiders in a phylogenetic context using different sequencing approaches and advanced bioinformatic pipelines to better understand the evolutionary history of the family,” Benjamin said.
Found throughout Asia, Synagelides is an unusual genus of minute, cryptic spiders that live in association with ants, often in soil ecosystems, including leaf litter. This goes for the Sri Lankan spiders too, which the researchers describe as having elongated front legs, possibly for burrowing into leaf litter. They also range from sandy-brown to black in color, “to blend [into] their environments in order to capture prey and defend themselves from predators.”
“Litter spiders are generalist predators and may be ideal bioindicators for ecological changes in soil ecosystems,” they write.
The role of spiders in the ecosystem is unique, Benjamin said.
“They are obligatory predators, preying on other arthropods, mainly insects,” he said. “They are natural control agents for our agricultural pests and help us maintain the balance. Some estimates have suggested that about a 50% crop loss can be expected in the absence of spider populations.”
In Sri Lanka alone, “about 110 new species of spiders have been discovered since 2000, over 90% of them endemic,” Benjamin added.
Inspired by the Bard
Benjamin and co-author Nilani Kanesharatnam named the species S. hortonensis after Horton Plains National Park in the central district of Nuwara Eliya, from where they described the type specimen. S. lakmalii, which they discovered from Maskeliya in central Sri Lanka, was named as a tribute to fellow scientist U.G. Sasanka Lakmali Ranasinghe, who collected the specimens for the research.
They also indulged in their love for literature by naming the other two species, S. rosalinadae and S. orlandoi, after the Shakespearean lovers. S. rosalinadae was described from the Kodigala summit of Mount Ritigala in Sri Lanka’s northwestern district of Anuradhapura, and S. orlandoi from the Kudawa area of the Sinharaja Forest Reserve, a UNESCO World Heritage site.
Benjamin said that “often, the sampling is very spotty as the studies are not designed to assess population size or the range. This is the likely case for most invertebrates in Sri Lanka.”
Benjamin identified habitat loss as a major threat to spiders in Sri Lanka, including through encroachment of protected areas, and clearing of forests for farming and housing.
“Our studies on spiders and beetles suggest that most of the taxa in our natural forests are endemic,” Benjamin said. “The best approach is to protect the ‘protected’ areas in Sri Lanka.”
He added that fear of spiders among people is unfounded when it comes to Sri Lanka, where there are no known records of human deaths caused by spider bites. “This is partly learned behavior and partly innate. Whether people fear spiders more than any other animal groups is unclear,” he said.
“In the absence of such records, this may be unfounded fear. I am not sure about the situation worldwide. I would be careful if I was in Australia or in the Neotropics,” he added.
Kanesharatnam, N. & Benjamin, S.P. (2020). First record of Synagelides Strand, 1906 (Araneae: Salticidae) from Sri Lanka: Description of four endemic species from tropical wet forest of the island. Zootaxa, 4790 (1), 43-56. doi:10.1116.16/zootaxa.4790.1.2
Banner image of Synagelides rosalindae, an orange-hued jumping spider newly described from the Kodigala summit of the historic Mount Ritigala, in the north-central Sri Lankan district of Anuradhapura. Researchers named the species after Rosalind Senior, the heroine of the Shakespeare comedy As You Like It, noted for her resilience, quick wit and beauty. Image courtesy of Suresh P. Benjamin.