Schistosomiasis, also known as bilharzia (bill-HAR-zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans.Although schistosomiasis is not found in the United States, more than 200 million people are infected worldwide.chistosomiasis, also known as bilharzia (bill-HAR-zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans.
Part 2: How do Dry Snorkels Work? Dry snorkels have a mechanism at the top of the tube that closes when you submerge under water. It also has a covering at the top to prevent surface water from splashing into the top of tube. The dry snorkel has a valve/hinge mechanism at the top. When you submerge underwater, accidentally or purposely, the hinge reacts via a float mechanism and closes onto the top of the tube and seals it which prevents water from filling the tube.
Dolphins Kill Fish With Sound. The other theory is that the dolphins use their nasal sacs to make sounds under water. These little sacs are found under the blowhole. When the dolphins go to the surface to take a breath, they pull the air in and close their blowhole.he dolphins can also make noise in response to what they see going on above water. For instance, if a dolphin is excited when a little girl pets him, the dolphin can open its mouth to squeak with delight. This other sound is produced by vocal cords inside the dolphin's throat.