Psychedelic Fish Crawls With "Legs"

February 25, 2009

In a week that seems full of funky fish comes yet another. I'd like to reintroduce you to H. psychedelica.

(Credit for images: ©David Hall/seaphotos.com)

I believe this fish has been "around" in the literature for a while, as I shared a photo a while back, but researchers have just named and fully documented it after analyzing its DNA.

With psychedelica's wild swirl of tan and peach zebra stripes, this denizen of the deep clearly earned its name. It also moves like some people did in the 60's, since researchers have discovered that it doesn't really swim. It instead hops like it's just had whatever was handed out at Woodstock.

This is a fish first.

While other frogfish and similar species are known to jettison themselves up off the bottom before they begin swimming, none has been observed hopping. Each time the newly identified species strikes the seafloor, it uses its fins to push off, expelling water from tiny gill openings on its sides to jettison its body forward. With tail curled tightly to one side –which limits the ability to steer – it appears to bounce haphazardly across the ocean floor.

Adults of H. psychedelica are fist-sized with gelatinous bodies covered with thick folds of skin that protect them from sharp-edged corals as they haunt tiny nooks and crannies of the harbor reef. Fins on either side of their bodies have, as with other frogfish, evolved to be leg-like, and members of H. psychedelica actually prefer crawling and hopping to swimming.

You can see its "legs" in this photo.

Theodore Pietsch, professor and curator of fishes at the University of Washington, led the recent research, which is published in the journal Copeia.

The species has a flattened face with eyes directed forward. It's something Pietsch, with 40 years of experience studying and classifying fishes, has never seen before in frogfish. It causes him to speculate that the species may have binocular vision, that is, vision that overlaps in front, like it does in humans. Most fish, with eyes on either side of their head, don't have vision that overlaps. Instead they see different things with each eye.

For more information, images and some great video of H. psychedelica, please visit this University of Washington News site.