In true science writer geekdom, I have spent the last week trying to figure out where the name “blenny” comes from. Of course, it comes from the suborder name Blenniodei (in the order Perciformes) and the family name Blenniidae…yada yada yada. But where does the blenn- come from?
Most scientific names come from Latin, but Google came up empty when I searched for Latin variations of blenn. Could it be someone’s name (eg. Dr. Blenn)? Again, my search proved fruitless. That left one logical explanation: the original blenny-namer was a toddler. Who else could match a cute little name with a cute little fish?
Anyone who knows Greek, apparently. It turns out that the name blenny isn’t that cute after all. Blenn- comes from the Greek word blennos, meaning mucus. And since there are approximately 833 species in the Blenniidae suborder, there are about 833 species of mucus fish. Nice.
Why the sudden interest in blennies? Well, I came across a paper about saber-toothed blennies. Don’t they sound vicious? Yeah…They’re not. They do have fang-like canine teeth and those teeth are connected to a venom gland. But they only use their built-in weapons to nip skin or mucus off an unsuspecting fish (much like naughty bluestreak cleaner wrasses).
My disappointment in the saber-toothed blenny left me searching for a cooler blenny—a mucus fish that could walk or talk or…leap. Meet the Pacific leaping blenny. These fish begin their lives in the ocean as planktonic larvae and then move to the supratidal zone, which is the rocky, splashy section of land above the high tide line. That’s right, these fish live on land.
Obviously, any normal fish living on land would be totally screwed. First, there’s the issue of breathing. Normal fish use gills to extract oxygen from the water. That same process would work just fine in air if it weren’t for the fragility of the lamellae (the part of the gills responsible for gas exchange). Out of the water, a fish’s lamellae will collapse, rendering gas exchange—and therefore breathing—impossible. To thwart suffocation, Pacific leaping blennies don’t breathe through their gills when they’re on land. Instead, they take oxygen in through their skin.*
Then there’s the issue of mobility. Normal fish swim. Swimming requires water. Critters that live on land tend to walk. Walking requires legs. The Pacific leaping blenny has neither, but such piddly details don’t really matter for a fish that can leap.
In a fantastically titled paper (“A Locomotor Innovation Enables Water-Land Transition in a Marine Fish”), Shi-Tong Tonia Hsieh describes the leaping maneuverability of these talented mucus fish. To launch itself, a Pacific leaping blenny curls its tail towards its head and pushes its tail fin into the ground, propelling itself forward and up at a speed of 1.5 meters/second (3.3 mph). Like this:
Ahem. I can’t embed the video. Click here to see it.
To travel shorter distances on land, they simply hop:
Again, the video issues…Click here to see the blenny hop.
I know what you’re thinking: These fish may be able to hop and leap, but what would they do if there were a vertical sheet of plexiglass in their habitat? Ironically enough, Dr. Hsieh had the same question. Here’s the answer:
Of course, I still can’t embed a .mov video so click here to see it.
*FYI: Walking catfish have a structure that strengthens their lamellae so that they can continue to use their gills on land.
Hsieh, S. (2010). A Locomotor Innovation Enables Water-Land Transition in a Marine Fish PLoS ONE, 5 (6) DOI: 10.1371/journal.pone.0011197