A long-tailed slug (Ibycus rachelae) Perhaps the rarest of the extensive invertebrate species group are slugs which, according to scientists, are infrequently encountered. At great altitudes on Borneo, several rare and highly endemic species appear to exist, including one new colourful green and yellow species, Ibycus rachelae, described from Sabah, Malaysia, in the Heart of Borneo. Discovered on leaves in primary montane forest at altitudes up to 1,900m on Gunung Kinabalu, the species has a particularly long tail, three times the length of its head, with a body length of 4cm. According to scientists, the slug has the habit of wrapping the long tail around its body when resting. From the Ariophantidae family, this unusual species makes use of so-called ‘love darts’ in courtship. Made of calcium carbonate, the love dart is harpoon-like which pierces and injects a hormone into a mate, and may play a role in increasing the chances of reproduction

Photograph: guardian.co.uk