Two New Spider Species Discovered in Uruguay. They Live in Silk-Lined Burrows

Two new spider species have been discovered in Uruguay. The spiders, Chaco castanea and Chaco costai, live in silk-lined burrows they build in sandy soils of oceanic and river coastal areas near psammophyte vegetation. These burrows are protected by a flap-like door that makes the spider burrows hard to find. The spiders are between 1 cm and 2 cm in body size. A male Chaco costai is pictured above.

The image below shows a female Chaco costai ready to ambush an unsuspecting insect. The spiders lift the entrance of their burrow slightly with their front legs and then wait and ambush prey. They return to their burrow after catching the prey.

Laura Montes de Oca, Instituto de Investigaciones Biologicas Clemente Estable, Uruguay, said in a statement, "Due to a number of life history characteristics, these spiders are difficult to collect and consequently little is known about their biology. Observations in natural conditions let us to know that they are mostly active during night. This knowledge is key to finding the spiders in order to perform the necessary studies, both on field and in laboratory. Remaining in the burrow most of their lives, makes these animals vulnerable to habitat perturbations. In Uruguay the psammophyte vegetation is critically decreasing, so it is very important to study and conserve the species."

The research was published here in ZooKeys.

Photos: Laura Montes De Oca

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