Pacific coral reef biologist Brian McNeil says our amazing little shortnose dragonfish, Eurypegasus draconis, doesn’t have a swim bladder and usually doesn’t swim. “It has to be really frightened to dart away. Even during a scare, it often prefers just to curl up its pectoral fins, which makes it resemble a small seashell, and hide in plain sight.” (The pectoral fins are indicated by the white arrow in the photo below.)
At 7 years of age, our female dragonfish is the oldest one of her species in an institution. In the photo below, she is shedding her entire skin (visible as a small piece of tissue at the upper right, next to the red arrow) which happens about once a week.
“Sea moth” is another name for this close relative of seahorses; its pectoral fins resemble moth or butterfly wings, and scientists have observed that individuals are able to change color to match their background. Even more amazing than their camouflaging ability is their preferred mode of locomotion. Their pelvic fins, located on the underside, evolved into walking appendages.
Shortnose dragonfish literally walk along the bottom searching for food, which they suck up by protruding their mouths downward and inhaling. The photo above shows the thin pelvic fins that resemble long fingers.
Found throughout the tropical and subtropical Indian Ocean, they feed on isopods, isopod eggs, crab larvae, tiny shrimp, copepods, goby eggs, Polychaete and other worms, and tiny mollusks. Observations indicate that they have long-term pair bonds, with the same female and male mating over several seasons.
Although shortnose dragonfish are not harvested for food, some sources estimate that millions of them are sold for traditional medicine each year, and live specimens are sold in the aquarium trade. Wild population numbers are not known, but there is concern that bycatch for bottom fish may have an even bigger impact than the medicinal and aquarium trades.
You can see the shortnose dragonfish in our Pacific Coral Reef exhibit at the Aquarium!