Flamboyant Cuttlefish, Metasepia pfefferi, ready to hatch from its egg.
Our submission for this week’s Photo Friday topic: Aliveis tiny a Flamboyant Cuttlefish (Metasepia pfefferi), about to hatch. We’ve shot this several times over the years; the first time was in Lembeh Strait, Indonesia in 2006. At the time, we had no idea how to tell when the cuttlefish would hatch, so we spent hours and hours over many days, watching them. We finally learned that when they are ready, the developed cuttlefish would turn these dark red, purple and orange colors, then suddenly without any other warning, pop out, a fully formed miniature of the adult.
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.