Fish Behavior
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.
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 … Read more Yawning Fishes
Here is your dose of fishy cuteness: The Signal Goby, a.k.a., Crabeye Goby, a.k.a., Twinspot Goby. Not only fun to watch, this fish has some pretty curious reproductive behavior, as we learned a few years ago. Signigobius biocellatus feeds by sand-sifting so we find them just off reefs or near shorelines in silty, nutrient-rich sand. We have seen them from Palau through Indonesia, so they aren’t really rare, but their populations are certainly not dense. Almost always found in pairs, … Read more More Fishy Cuteness: The Signal Goby
More fascinating mimicry: the filefish and the puffer. The little Mimic Filefish, Paraluteres prionurus not only looks like the toxic Black Saddled Toby, Canthigaster valentini, it is often found swimming around in tight little mixed groups of both species. When I started looking for the filefish, they turned out to be more common than I thought and I realized I had likely been seeing them all along but had been lumping them in with tobies. This is an example of Batesian mimicry in which a palatable … Read more Mimicry: The Filefish and the Puffer
This week’s Photo Friday topic is Dad. The Yellowhead Jawfish male incubates a ball of fertilized eggs in his mouth for 5 to 7 days before releasing the hatching larvae. In this photo, the fish is aerating the eggs in a process called churning, in which the fish spits out and turns the eggs in a series of rapid motions. More about this fascinating little fish, including a photo and video of a dad releasing his eggs, is featured in … Read more Photo Friday: Dad
March 2013 – Waigeo, Indonesia In October 2012, I found a tiny fish that I couldn’t identify. It was wary, darting into a small hole when I got too close. I shot video, noted the location and on the afternoon dive, navigated back to it so Ned and several others could take photographs. Back on the boat we decided, based on its body shape and distinctive dorsal fin that it had to be a juvenile Doublebanded Soapfish (Diploprion bifasciatum). Other … Read more Soapfish Tales
This image of spawning Striated Frogfish is not new. We wrote about our 2009 Blue Heron Bridge adventure in Alert Diver Magazine in an article we called “Caught in the Act” (you can click here to read it online). We were lucky to get the photos and video – it was a combination of being in the right place at the right time and recognizing what was about to happen. I’m posting it here because I just created a Blennywatcher video channel … Read more Spawning Frogfish
Lembeh Strait, Indonesia ~ Well the table is turned. I have seen prey in the grips of toothy lizardfishes before, but never this. What is going on here? From a distance I could see Ned watching what I thought was a lizardfish (quite a predator on the reef) trying to eat a razorfish. Then I realized the razorfish was firmly clamped onto the lizardfish – quite a reversal from the expected. Ned had a better angle and was able to … Read more Razorfish Bites
Lembeh Strait, Indonesia ~ October 2012 Here is one of my favorite examples of mimicry in fishes: a Striped Fangblenny (Meiacanthus grammistes) model and its mimic, a juvenile bream, Scolopsis bilineatus. Neither fish is that uncommon on the Indo-Pacific reefs where we dive but this was the first time I took the time to follow a little Bridled Monocle Bream to see if it would lead me to the blenny that it is known to mimic. The relationship of this bream … Read more Mimicry: The Blenny and the Bream
November 2012 ~ We have just returned from a cruise aboard the Dewi Nusantara around Batanta and Waigeo, two islands in the Raja Ampat region of eastern Indonesia. If I had to rank my top 10 favorite dives of all time, I would include a 2007 night dive off Batanta when we saw this frogfish, Lophiocharon sp., with her clutch of eggs. The only divers still in the water after a two-hour dive, we were on our way back to … Read more Frogfish with Eggs