Sea Walnut, American comb jelly, Warty comb jelly or Leidy's comb jelly (Mnemiopsis leidyi). Adriatic sea. A small, transparent sea creature on black background. Tiny jellyfish. Underwater world.

Science

5 of the ocean's weirdest-looking creatures

Shutterstock

Deep sea spiders live on the ocean floor (some 2300 feet deep) and can grow nearly 3 feet wide.

The ocean sunfish or mola mola is one of the heaviest bony fishes.