One Fish, Two Fish, Red Fish, Blue Fish: First Live "Color Changing" Sea Toad Spotted!

This bulbous red fish with spiky scales and foot-like fins is a species of Sea Toad (Chaunacops coloratus)that has never been seen alive – until now! Researchers are thrilled to have spotted this rare deep-sea fish in its natural habitat. In addition to documenting it “walking” along the ocean floor and fishing with their built-in lures they’ve documented that it actually changes color from blue to red as it ages.

C. coloratus was first described from a single specimen collected off the coast of Panama during an expedition in 1891 aboard the U.S. Fish Commission steamer Albatross. However, for over 100 years, marine researchers collected deep-sea fish using trawl nets and dredges, so this anglerfish was never seen alive. That changed in 2002, when researchers from MBARI, Moss Landing Marine Laboratories, and the Monterey Bay National Marine Sanctuary used the remotely operated vehicle (ROV) Tiburon to explore Davidson Seamount—an extinct volcano off the coast of Central California.

Then, in 2010, MBARI researchers observed six more of these unique fish during ROV dives at Taney Seamounts, another set of extinct volcanoes off the California coast. This time, the research team noticed that not all of the fish were red or rose-colored, as they had previously been described in the scientific literature. Instead, some of the fish were blue.

After comparing the sizes of the fish in ROV videos, the scientists noted that the red fish were larger and more mature, while the blue fish were younger and smaller. From these observations, they inferred that this fish likely begins its life in a transparent larval form, turns blue as a juvenile, and turns red at adulthood.

As a result of MBARI’s ROV observations, researchers also learned that C. coloratus can live as deep as 3,300 meters (11,000 feet) below the ocean’s surface. Previous trawl-net collections suggested that the fish lived only at depths of 1,250 to 1,789 meters (4,100 to 5,900 feet).

Definitely a great find – thanks MBARI!