Arachnologists from the Department of Zoology, Christ College, Irinjalakuda, have rediscovered two rare species of spiders on their college campus after over a century.
The first species discovered, Micropholcus fauroti, is a member of the long-legged spider family Pholcidae. It was first reported in 1887 from the African country Djibouti by the renowned French arachnologist Dr. Eugène Louis Simon. Now, a team of researchers from the Centre for Animal Taxonomy and Ecology (CATE), associated with the Christ College, rediscovered the species after over 134 years, says Sudhikumar A.V., Head of the Department of Zoology.
“This tiny spider measures only 2 mm long. It possesses eight minute shiny eyes arranged in four groups. The pale-yellow body is marked with white spots. It has very fragile long legs and builds irregular cobwebs under green leaves. Female spiders lay white bead-like eggs encapsulated in spider silk threads and carry them in their mouth,” says Mr. Sudhikumar.
The second species is Tetragnatha cochinensis, belonging to the family of long-jawed spiders ( Tetragnathidae). Both male and female of the species possess long jaws.
“In 1921, former director of the Government Museum, Madras, and renowned British arachnologist Dr. Frederic Henry Gravely described the inventory of a new species of spider from the Athirappilly forests of Kerala. After this, it was believed that this spider became extinct,” Mr. Sudhikumar points out.
Dr. Gravely’s inventory was based only on female specimens. Recently, the CATE team rediscovered both male and female specimens of the species, he adds.
The male is characterised by the presence of four internal teeth and three external teeth. There is an elongated curved spine-like structure at the tip of the jaw, which is used to hold females during mating. The female is characterised by the presence of 16 internal teeth and eight external. There are white spots and black lines on the dorsal surface of the elongated abdomen. There are mid longitudinal dark lines on the light yellow-coloured head of both male and female. Eight black eyes are arranged in two rows.
Circular webs
“These spiders construct perfect circular orb webs in grasslands associated with water bodies. They hide under grass blades during the day and feed only at night. Females lay 8-10 eggs and protect these under grass blades where they incubate,” explains Mr. Sudhikumar.
The study was funded by the Department of Science and Technology (DST), the Government of India, and University Grants Commission. The research team includes Vishnu Haridas, Anju K. Baby, research scholars of the CATE and Dr. Usha Bhagirathan, Assistant Professor, Department of Zoology, Sree Kerala Varma College, Thrissur.
The findings were published in the latest volume of Serket, an international scientific magazine published from Egypt.
