Jellyfish can produce offspring both sexually ... In the 1980s a rapidly multiplying species decimated Black Sea fisheries. Beroe abyssicola, 4.7 inches long Aequorea victoria.

You may have heard about the "immortal jellyfish," which was discovered ... "There is a theory that the collapse of fisheries in the Black Sea [in the 1990s] was caused by Mnemiopsis," said ...