Fish Behavior
Dumaguete, Philippines ~ April 2015 A blenny guarding eggs! The last time I spent a dive watching a male blenny guarding a cache of eggs, was in freezing water with 3 feet of vis – in Florida, of all places! Since that dive (see Blenny Fever), I’ve seen quite a few different species of blenny spawn but their eggs are difficult or impossible to see because they tend to lay them in abandoned worm tubes, shells or crevices. I think this … Read more
Dumaguete, Philippines, April 2015 ~ I am starting this entry with one of Ned’s photos of tube-dwelling amphipods. These creatures were almost my sole focus during our three weeks of diving, first in Dumaguete, then in Anilao. I didn’t realize the extent of my obsession until I started cataloging video and reading my journal entries – yikes! This was our second visit to the Philippines. Our first trip in January 2011 was good – we saw ghost pipefishes, nudibranchs, skeleton … Read more
Pantar, Indonesia (May 2014) ~ I just saw a blenny that I don’t recognize and you have to go back to see it. Ned nodded in assent, barely looking up from his laptop. Our liveaboard dive boat, the Dewi Nusantara, was scheduled to remain in this bay for one more day, so I had the evening to persuade Ned to return to the dive site the next morning instead of exploring another spot. And we had to go back – … Read more
Recently, during a get-together of diver friends, the subject of parrotfish cocoons came up – I don’t remember why – and surprisingly, several said they had never seen a parrotfish sleeping in a mucous cocoon. After thinking about it, Ned and I realized that in all the hundreds of night dives we’d made, we had only seen it maybe a half dozen times. We encountered it for the first time in the mid-90s off Key Largo while waiting for the … Read more
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
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 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
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
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