Common Stretch Spider

• Its defence is its posture: it stretches out full length along a stem, with the front legs extended forwards and the hind legs backwards, and becomes practically indistinguishable from the grass itself.
• The males have enormous chelicerae, which they use to lock the female's during mating and so avoid being bitten.
• It is told apart from the other Tetragnatha by the minute curved tip of the male's conductor and by the shape of the female's epigyne — in other words, only under a binocular microscope.
• Its body is extremely long and slender, and at rest it stretches out lengthways along a stem with its front and rear legs extended in a line, becoming practically invisible.
• It weaves over water, and its diet depends largely on emerging aquatic insects: mayflies, chironomid midges and caddisflies. It is a link between the aquatic and the terrestrial ecosystem.
• Its chelicerae are enormous and prominent, above all in the male, and they are used in mating: male and female lock fangs, in a posture that lets him come close without being attacked.
• Its genus is famous for another reason: in Hawaii it has starred in a spectacular adaptive radiation, with dozens of species arising in the archipelago and colour ecotypes repeated independently on different islands, a textbook case of convergent evolution.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat & environment

Low vegetation in damp places: river and pond margins, reedbeds and waterlogged meadows, where it spreads its web to catch flying insects

Sources consulted: World Spider Catalog; Wikipedia (Tetragnatha extensa); Dondale et al., The Insects and Arachnids of Canada; Arácnidos Ibéricos

Best time: From spring to summer, on the low vegetation of damp ground