WTF? (WHAT’S THAT FISH) 10: FLYING GURNARD
Imagine that you are swimming along resplendent in your snorkelling gear (me) – or in scuba gear for the advanced swimmer (you). There, below you, camouflaged against the sea bottom is a fish. A strange-shaped brown sort of creature with odd side fins. As it progresses over the gravelly sand, your immediate reaction is ‘what the…?’ Its fins seem to be turning into… wings. Like this:
Yes, it’s a flying gurnard. Unlike flying fish, it can’t actually fly through the air. But once its wings are fully spread, it certainly looks as though it could.
WHAT’S THE POINT OF THE WINGS IF THE THING CAN’T FLY?
This gurnard species usually gets around using its ventral fins as ‘legs’, with the pectoral fins (‘wings’) close to the body. There seem to be several possible reasons for possessing the ‘sudden-deployment-of-flashy-wings’ superpower.
- It surprises and deters predators by movement, turning prospective prey into an apparently different creature
- Bright or lurid colouring may be a deterrent warning of a foul-tasting or poisonous species (APOSEMATISM)
- A creature may actually be harmless and even tasty (as here) but may appear to be unpalateable or poisonous (BATESIAN MIMICRY)
- In any event, the wings enable the fish to take off from the sea bottom and travel faster by ‘flying’ thought the water to escape a predator
I had a quick look to see how scientists in history had depicted this extraordinary fish. The earliest illustration I could find was taken from “Allgemeine Naturgeschichte der Fische (General natural history of fishes),” a 12-volume encyclopedia by author/illustrator Marcus Elieser Bloch (1723-1799), which described all fish species then known to science (and 267 previously unknown) (© AMNH\D. Finnin) sourced from ‘Hyperallergic’
Here’s a short video of a flying gurnard on the move, from ‘Sia Big Fish’
Credits: All main images Adam Rees / Scuba Works with many thanks, except final one ‘cralize wiki’; Hyperallergic for the historic image; Sia Big Fish for the video