Munk’s Devil Ray
Mobula munkiana

Physical Description

• A small devil ray, only three feet in wingspan.
• They have a diamond-shaped body, with two distinct jutted points on head.
• Back coloration is black, purple, or purple-gray, and belly coloration is white.
• There are no spines on its tail.

Range

• From Baja California to Peru.
• Galapagos Islands, Cocos Island, Malpelo.

NOTE: These rays are not native to the range of the map, but we included it to honor Walter Munk, its namesake. Because it is not native, it is on the very edge of the map.

Habitat

• They prefer shallow inshore waters.

Reproduction

• Ovoviviparous, meaning the embryos develop in egg sacs inside the mother before being born live.
• They have one pup per litter.
• The gestation period is currently unknown.

Diet

• Mysid shrimp, planktonic crustaceans, small fishes.

Predators

• Orcas, hammerhead sharks

Interesting Facts

• Munk’s devil rays can breach up to ten feet in the air, landing on the water with a loud slapping sound.
• Scientists do not yet know why they leap.
• It has the nickname “tortilla” from local fisherman, due to its small size and the slapping sound when they land in the water sounding like the smacking of tortilla dough between a cook’s palms.
• Munk’s devil rays can be seen traveling in groups numbering in the hundreds of thousands, all jumping together.

Photo Octavio Aburto

Sources: Science Friday; Fishbase; Elasmodiver.com

The Munk’s devil ray was named for Walter Munk in the 1980s by Scripps ecologist Giuseppe Notarbartolo di Sciara, who saw Munk as a mentor. As for why they leap, Walter’s theory was as such, “I said they just jump for the joy of it. Why shouldn’t they jump for the joy?”

To see Walter see his namesake for the first time, watch the trailer for the documentary Spirit of Discovery.