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 the tender when our dive guide Ali called us back to the shallow reef. At the time, the only photo we had seen of a frogfish with eggs was from an aquarium. Over the past five years, several other photos have appeared on various online sites, taken, I believe, in the same region, but there is still very little information about the natural history of this intriguing fish.
I knew we would be returning to the Batanta dive site on this most recent trip and hoped against hope that we might find another of this species, but no luck. We have seen what I think is the same species in Aljui Bay in Waigeo. There we saw a female being chased around by two courting males, but unfortunately did not have the luxury of returning to the site in the evening, when they were surely going to spawn (that video, along with the frogfish with eggs is included on the Sensational Seas Two DVD that I produced in 2010 as a fundraiser for REEF).
Frogfish, also known as anglerfish, have a highly modified first spine of the dorsal fin called the illicium, that can be rotated freely and works like a fishing rod. It is tipped with a fleshy tab called the esca, or lure. Two frogfish that are very similar, Lophiocharon trisignatus (Three-spot Frogfish) and Lophiocharon lithinostomus (Marblemouthed Frogfish) have similar ranges and both tend large eggs, carried by the female, attached to her side. The distinguishing characteristic is the esca: L. trisignatus has a fleshy lure; it is nearly lacking on L. lithinostomus. In 2007, when we originally shot the photos and video, we identified the fish as Lophiocharon trisignatus, based on the lure. You can see in the screen capture below that the frogfish has a fairly distinct lure:
Now, five years later, having looked at currently available images, I’m leaning more toward L. lithinostomus, but still not certain. Feel free to comment if you have an opinion. Meanwhile, check out my Frogfish with Eggs video on our Blenny Watcher YouTube channel or click below. If you watch the close-ups carefully, you’ll see the little embryos moving inside the eggs: