It was identified as a predatory aquatic bug (family Belostomatidae), Belostoma, possibly indicum. The bug lives in fresh or slightly salty water. It swims about actively and rests floating just below the surface, breathing through a connection to the air in its rear end. It catches other aquatic insects and small fish with its grappling front legs, and sucksbody juices out of them with piercing mouthparts.

Later (May 2011), a moderator said, “it is also called the electric bug or the giant water bug, Lethocerus sp. It used to be Belostoma sp., such as Belostoma indicum belonging to Order Hemiptera, Family Belostomatidae.