The isonade possesses a long, dexterous, hooked tail it uses to snatch up its prey. Sailors near the edge of their boat may suddenly be pulled overboard before they can even shout, and the isoande has the uncanny ability to sneak up and perform such attacks while no one else is looking. One by one, the boat's crew may disappear, with the terrified sailors unaware of the monster's presence. Even travelers on large ships, where the deck is far above the water's surface, are not safe. When the isonade spots an isolated target near the railing of such a ship, it can leap 40 feet out of the water reach its victim, yanking them overboard to a watery grave.
This monstrous shark stalks busy fishing routes, preferring stormy or murky waters that reduce visibility and help it to sneak up on it prey. The isonade's preferred prey is not the fish along these routes but the fishermen, and its victims are often snatched right off their boat without a trace of their passing.