This is our entry for this week’s Photo Friday Challenge: Twilight. Spawning hamlets can be seen at twilight. This is an interesting time on the reef – daytime fishes have bedded down and the night-time feeders haven’t yet emerged from their hiding places. A few fishes, like the normally solitary hamlets, take advantage of the low light (presumably to avoid predators) and pair up at twilight to spawn. Ned calls it the best peep show on the reef.
Excuse me fish, am I boring you? Lacy Rhinopias giving us the full stretch.
We see fish yawn fairly often, but have to be in the right place at the right time to capture the behavior. In Papua New Guinea, this Lacy Rhinopias, a member of the scorpionfish family, was on the same coral head every day for a week so everyone had a chance to photograph it from every angle. Ned saw it yawn from a distance and knew he wanted that head-on shot, so he went back and sat for quite a while, waiting for the right moment to press the shutter button. This is how it usually happens – we see it from a distance then try to position ourselves for the shot and wait. Sometimes the fish will yawn again right away; sometimes it can take 30 minutes.
While we associate yawning in humans with boredom or sleepiness, I’ve heard a few different theories about why fish do it. One is that they are stretching their mouths to be ready to feed – kind of like flexing their muscles. Another is it is a sign of annoyance or warning, like “Hey you with the big camera – back off!”
Is the frogfish yawning to flex its muscles or to threaten us?
While I was looking for information about fish yawning, I came across this cool site about yawning with everything you could ever want to know about the topic. It has a number of articles about yawning in fishes, including one that concludes it increases muscle tone, aiding in preparing the animal for action.
This week’s Photo Friday Challenge is Plant Kingdom. Seagrass is a flowering plant, sometimes found in huge underwater meadows. Seagrass beds are one of our favorite underwater habitats – we never know what we’ll find – like this spotted snake eel.