Creature Feature #416: Leech

Leech are blood-suckling annelids, generally found in rainforest or water. Currently 700 species are recognised, of which around 12% are terrestrial. This species, the Tiger Leech, is a terrestrial species,  found in the moist forests of Borneo. Leeches are characterised by their anterior and posterior suckers. The posterior ones anchor the creature to a surface, as they wait for prey to brush past.  With the blood-scuking species, the mouth connects with the prey and attaches using suction. A mucus secreted into the host's bloodstream prevents the blood from clotting and numbs them to recognition. Not all species are capable of biting - some require a wound to be already present - and others do not drink blood at all, but instead devour invertebrate prey whole. The leech will remain attached until it becomes engorged with blood, at which point it will drop off, although the wound may bleed for a time afterwards.