Did you know that filefish sleep at night, like this pair of thread-sail filefish (Stephanolepis cirrhifer)?
They clamp onto something with their mouths, in this case a discarded line, perhaps for stability and to avoid drifting away.
Sleeping filefish stay alert to some degree when they slumber, sort of in a semi-dazed, semi-aware state. I assume that they can react if somehow threatened.
I came across these fish when I was looking for something else. That something else decided not to show up, which has sort of been a thing for the past several months, so I groaned, re-jiggered gear and photographed this sleeping pair instead.
There were actually eight filefish orally affixed to various points along the line, but the perspective of the lens I had was such that there was no way I could fit all the dozing piscines into a single frame, even though it could’ve made for an interesting natural history image.
Afterward, I learned that a bunch of filefish (what is the collective noun for a group of snoozing filefish?) sleep pretty much in the same place every day. Cue appearance of lightbulb over head (à la Wile E. Coyote) as I hatched the (self-perceived) brilliant scheme of going back to get the photograph that I had imagined in my mind’s eye when I initially saw the slumbering fish but couldn’t take because I had the wrong gear.
A few days later I visited again, this time properly equipped for the purpose of capturing an image with multiple fish holding onto the line with their cute little puckered-up mouths.
And of course, you know what happened. The fish weren’t there. They were undoubtedly somewhere around the corner snickering at me.
Accustomed as I am to having my best-laid plans crushed, I quickly formulated a new strategy and took the following photo of a filefish that was looking for a place to settle for the evening.