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124. Weedy Scorpionfish (Rhinopias frondosa) (yawning)


A Weedy Scorpionfish (Rhinopias frondosa) Yawns. The Rhinopias, also known by its generic name, is one of nature's most unusual yet beautiful fish species. Zoologist Albert Günther first described this scorpaenoid fish species in 1892 as a Mauritian fish species.

Although they are found from South Africa to Australia and north to Japan, and to the Caroline Islands in the east, they are commonly associated with the waters of the Coral Triangle. Despite having collected over a thousand dives in Indonesia and only a few hundred in Mauritius, I am convinced that this species is encountered more frequently in Mauritian waters than in the rich and diverse reefs of the Coral Triangle.

These fish are usually exceptionally well-camouflaged and can easily blend into the surrounding weeds on the reef, making them easy to overlook without proper lighting. With fleshy tentacles and an atypical shape, they resemble the leaves and seaweed of algae. Weedy Scorpionfish move in the same way as the surrounding weeds and algae, making it nearly impossible to spot them in seaweed-rich areas due to the rhythm of the ocean's motion.

The specimen in this underwater clip was filmed on one of Bali’s northern slopes. With the illumination of my video lights this Weedy Scorpionfish had the same colouration as the grey greenish seaweeds its was crawling over.

As a fish species that lacks a swim bladder, they crawl or crutch along the substrate using their pectoral and pelvic fins, only swimming when really necessary.

As members of the scorpionfish family, Weedy Scorpionfish are highly venomous, and their venom can, under certain circumstances, be fatal to humans. Like their family members, their venom is delivered through one or more of the fish's twelve dorsal spines. These fish are ambush predators, gaping and sucking in passing prey, which they swallow whole. They primarily feed from dusk till dawn, with little fish and crustaceans most of the time being their prey.

Just like the Scorpion Leaffish (Taenianotus triacanthus) a close relative, the Rhinopias moults occasionally and can change colour after moulting. It is believed the Rhinopias does so to get rid off parasites that infest his skin.

Rhinopias are highly sought-after fish by scuba divers and a favourite subject for underwater videographers and photographers due to their beautiful and unique appearance. Seldom encountered because they are nocturnal species, they are less likely to be seen during the daytime when most divers are in the water, and they are also not abundant.

As a result, when underwater video enthusiasts and photographers encounter a Rhinopias, they are generally very excited. Some consider these fish to be the Holy Grail of underwater photographers and marine wildlife videographers; I simply consider them to be a marvel of evolution.


A yawning fish is always a great photo or video opportunity. Nobody knows precisely what triggers a fish to yawn, but in my experience, fish tend to yawn when you are in their face with your camera. The key is to be close enough for the fish to be annoyed by you, which may result in a yawn. However, if you become too threatening, the fish will just flee.

More on this topic:

For a more in-depth description about the Weedy Scorpionfish please go to our vlog post 96 or click on this link:

and vlog post 97 or click on this link:

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