A common toadfish (Tetractenos hamiltoni) investigating some suspicious bubbles in the mangrove shallows near Nudgee.

I once met a man who could hypnotize toadfish. He would stand ankle-deep, on the mudflats of Bramble Bay, with his heels together like Dorothy. And the little common toadfish would swim into the ‘V’ created, and become still. Not many people like toadfish, but this man did. He would scoop them up gently into a water-filled tray for everyone to have a closer look, and told us they could eat plastic bags, and in this way helped to clean up the estuaries.

Toadfish are members of the family Tetraodontidae, which means ‘four teeth’, referring to their four large teeth that are fused together in upper and lower pairs, forming a robust beak. Many people are scared of these teeth and dislike toadfish because they steal bait and contain the deadly poison tetrodotoxin. This toxin makes a relative of the toadfish – the fugu or Takifugu – highly prized by some Japanese daredevils, who get specially licensed chefs to dish it up with only traces of the poison remaining. It’s supposed to make your lips tingle, but a slip-up by the chef means death to the diner. Tetrodotoxin is actually produced by symbiotic bacteria, and is also found in the blue-ringed octopus. Interestingly, some fish appear to be resistant to the toxin, as anglers often find toadfish in the bellies of larger fish.

A fearsome relative of the toadfish is the ferocious pufferfish, Feroxodon multistriatus, which has a reputation for removing parts of people’s toes and other dangling appendages.  It’s a striking fish (no pun intended) as you can see from the video below filmed at Orpheus Island by Daniel Vaughan. Daniel kindly gave permission for me to include it here:

Mr Ferocious P made Shute Harbour in the Whitsundays a dangerous place for paddlers in the 1970’s (and it probably still is today). Poor little Margaret Lewis, 6 years old, had the ends of two toes bitten off. Another lad had a ‘walnut-sized chunk’ taken out of his leg, and a wading fisherman was chased onto dry land by a 65 cm pufferfish later dubbed ‘Thomas the Terrible toadfish’. Maybe it was trying to get back at all those kiddies (and adults) who think it’s funny to torment pufferfish to make them puff up. The ferocious pufferfish frequents inshore shallow waters of northern Australia, along with stonefish, stingrays, stinging jellies and other antisocial creatures who might convince you to head for the local swimming pool rather than the beach.

But my favorite toadfish relative is the amazing sunfish Mola that can grow up to 2 m long and 1 tonne in weight.

A Sunfish or Swimming head (Schwimmender kopf: German)(Mola mola). Image by Per-Ola Norman via Wikimedia Commons.

This enormous fish lives up to its german name – Schwimmender kopf or ‘Swimming head’ – as its tail has been lost and the rear end of its body is reduced to a leathery flap. Sunfish cruise about the open oceans feeding on jellyfishes, using powerful thrusts of their large dorsal and anal fins to propel them forward. About 300 million eggs can be produced by the ocean sunfish Mola mola, which probably makes it the most fecund fish species in the world.

The monster sun fish caught by W.N. McMillan of E. Africa, at Santa Catalina Isl., Cal. April 1st, 1910. estimated wt. 3500 lbs. Image courtesy of the Library of Congress.

Check out oceansunfish.org for the latest news on ocean sunfish sightings and research.

So next time you see a little toadfish, remember this: they might seem inconsequential and a nuisance to anglers, but they certainly have their place in the estuary. Other fish eat them, they clean up rubbish, and they even have the potential to be used as indicators of ecosystem health.

They also have some very formidable relatives that you wouldn’t want to meet in a dark, underwater alley.

References:

Colfelt,D. (1985) 100 magic miles of the Great Barrier Reef. Windward Publications Pty. Ltd., Sydney.

Grant,E.M. (1997) Grant’s Guide to Fishes. E.M.Grant Pty. Ltd., Redcliffe.

Kuiter,R.H. (1996) Guide to sea fishes of Australia. New Holland, Frenchs Forest.

Mat Piah,R. and Bucher,D.J. (2014) Reproductive biology of the estuarine pufferfish, Marilyna pleurosticta and Tetractenos hamiltoni (Telostei: Tetraodontidae) in northern New South Wales: implications for biomonitoring. Proceedings of the Linnean Society of New South Wales 136:219-229.

Nelson,J.S. (2006) Fishes of the World. 4th Edn. John Wiley and Sons, Hoboken.

Su,J. et al. (1986) A new generic name for Anchisomus multistriatus Richardson 1854 (Tertraodontidae)
with notes on its toxicity and pufferfish biting behaviour. Rec.West.Aust.Mus. 13:101-120