Researchers have found five new species of armored spiders lurking deep in the darkness of limestone caves in southern China.

 

The family of armored spiders (Tetrablemmidae) -- named such because the complex pattern of the plates covering their abdomen look like body armor -- are small to medium-sized and mostly collected from leaf litter and soil in the humid tropics and subtropical regions. Like these new cave-dwelling ones, the soil inhabitants show adaptations to living in the darkness: mainly, the loss of eyes. Two of these new spiders, for example, have only four eyes. Most spiders have eight. 

 

The number of Tetrablemmidae spiders, if you’re keeping count, is 144 species. Two of the new spiders belong to the genus Singaporemma, two belong to genus Tetrablemma, and one is in a whole new genus, Sinamma, derived from “sina” for China. Shuqiang Li from the Chinese Academy of Sciences and colleagues based their decisions on the female spiders’ genitalia and the male spiders’ palp (a mouthpiece used to transfer sperm to females), along with various measurements of their carapace (outer shell) and legs. 

 

 

They were all collected from the South China Karst, a protected UNESCO World Heritage Site and spans the provinces of Guangxi, Guizhou, and Yunnan. Li and colleagues have explored 2,000 of those biodiversity-rich caves and reported several hundred new species. That brings China’s spider species count to 4,300 from 2,300 in the last decade.

 

The findings were published in Zookeys this week. 

 

Images: Sinamma oxycera male (A,B) and female (C,D) from Shuqiang Li via CC-BY 4.0