Larval Schistosoma parasite

A cercaria (larva) of the flatworm parasite, Schistosoma japonicum, struggles to release itself from the digestive gland of an infected host snail (Oncomelania spp.) into the surrounding water. Right at the end of the clip, the larva swims off being propelled by its forked tail. Infected host snails can release thousands of such cercariae (pl.) over time. The larvae wait for a passing mammal (e.g., human) and actively penetrate skin thereby initiating the disease known as schistosomiasis.