The sea walnut or warty comb jelly is a species of tentaculate ctenophore. These are found in western Atlantic coastal waters. These have oval-shaped and transparent body with four rows of ciliated combs that run along the body vertically and glow blue-green when disturbed.
Their body contains 97% water. They are small organisms, having a maximum body length of roughly 7–12 cm and a diameter of 2.5 cm. They eat other comb jellies and eggs and larvae of fish. It is sometimes known to eat smaller individuals of its own kind. It also has several other predators.
Many are vertebrates, including species of birds and fish. The species is blind, has no brain and moves so slowly that it is referred to as “sea walnut”. These wonderful creatures are also known to form dense swarms. Their bluish white luminescence produced by their comb like organs can make the sea glow in the night.