Ogrefaced Spider

• comportamientoIt weaves a small net, holds it in its front legs and throws it over passing prey, rather than waiting for anything to blunder into a fixed web.
• Its two posterior median eyes are the largest simple eyes of any arthropod and let it hunt in light hundreds of times dimmer than a cat needs.
• Every night it builds a light-sensitive membrane that gives it that extreme night vision, and every dawn it destroys it.
• It has been shown experimentally to hear: it detects the hum of insects approaching from behind with its legs and casts the net backwards without seeing them.
• It fishes with a net. It weaves a small, highly elastic rectangular web, holds it with its four front legs and waits hanging upside down; when prey passes, it stretches the net out in a flash and wraps it up.
• It has the largest eyes of any spider in proportion to its body: two enormous rear eyes that give it a sensitivity to light greater than that of cats and owls, and that let it hunt in near-total darkness. Hence the name ogre-faced spider.
• Those eyes are so sensitive that they degrade in daylight: at each dawn it breaks down part of the photosensitive membrane and regenerates it at the following dusk.
• It also hunts backwards: it detects insects flying behind it with the sensory hairs on its legs and casts the net upwards without seeing them.
• A 2020 study showed that it can hear: it responds to low-frequency airborne sounds, something thought impossible in a spider without eardrums.
• By day it stretches out against a branch, and its elongated brown body makes it indistinguishable from a dry twig.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Understorey and low vegetation of warm forests in the south-eastern United States and tropical America

Sources consulted: Stafstrom y Hebets (2016), Biology Letters; Stafstrom et al. (2020), Current Biology; Universidad de Florida, Featured Creatures