Spotted: Frogfish!

IMG_0003There are 44 species of frogfish (also know as anglerfish), 9 of which we are fortunate enough to spot on several of our local sites. Frogfish are atypical in appearance to most fish, with an unusual and stocky shape. They are highly adapted to their environment; able to camouflage by mimicking coral, sponges, stone and even urchins.

Rather than normal dorsal fins, Frogfish have a “rod” (their front-most three fins) topped with a “lure”, as well as pelvic and pectoral fins.

One of the most fascinating things about the frogfish is the way they capture prey. The fish use their “rod” to clamber over the sea floor toward prey, turning so their mouth is positioned towards the prey, and crouch. Next they will ‘strike’, where the mouth is thrown open, upper jaw protruded and oral cavity expanded 12 times in volume with lightning speed to suck in the prey (along with a large volume of water). The gill openings are clamped closed using pectoral fins, the oral and gill cavities contracted, and the contents of the mouth forced into their expandable sac-like stomach for digestion. From a divers perspective, the entire manoeuvre is so fast that all we observe is prey entering the frogfish’s strike zone, and then suddenly disappearing an a bulge appearing in the frogfish. This strike is much faster than that of a cobra or mongoose, and they are able to swallow prey far larger than themselves.

Frogfish also reproduce unusually – females releasing eggs with a mucous coating that expands into an ‘egg raft’ 10cm x 40-90cm long. It is thought the male fertilises the eggs as they are released by the female.

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