Long-Jawed Spider Moves across Water with and without the Use of Silk

Abstract

Among spiders, movement in aquatic environments, including below the water’s surface or on the surface film, is completed using a variety of techniques that do not involve the use of silk, including swimming, walking, and rowing. The use of silk to assist with aquatic locomotion has been explored only to a limited extent. In this study, we report on observations of a long-jawed spider (Family: Tetragnathidae) from Australia, Tetragnatha nitens, moving across the surface film in two different manners, one of which involves the use of silk. The first observation was of a female T. nitens walking across the water’s surface when prompted by a predation attempt: the spider used its front three pairs of legs for propulsion while the back pair remained motionless on the water, likely for stabilization. The second observation featured a male T. nitens utilizing a silk line to reel itself towards emergent vegetation while gliding across the water. Our findings support work on other long-jawed spiders, revealing that individual species can exploit several strategies for moving across water, including those that involve the use of silk. This study sheds light on the remarkable adaptability of spider silk and its potential use in aquatic systems.