Sunday 5 July 2015

Australian Prowfish

Image: John Turnbull
A prow is the pointy, front end of a boat. It serves to cut through the water as the ship makes its way through the waves.

Australian Prowfish do look a bit like prows but they're most certainly not cutting the waves at full speed. They're far too lazy for that kind of thing and even if they tried, it turns out they'd have a tough time keeping to a straight line...

Image: John Turnbull
It takes a mere glance to see why Australian Prowfish wouldn't want to move around much. They're simply not built for it. Take a look at that bulky blockhead. Hardly the streamlined noggin of a fishy athlete. And what about that puny tail fin? Not at all a mighty tail to power them through the sea with a single swish.

That's one sweet dorsal fin, though! It extends from their forehead and runs all the way down their body. Aside from that, they have a pair of large pectoral fins but no pelvic fins whatsoever.

Image: John Turnbull
All that is only from the side. Look at them from the front and they're so compressed they disappear almost entirely!

There are three species of Australian Prowfish making up the Pataecidae family, all found in the more southerly coasts of Australia.

Image: Klaus Stiefel
Red Indian Fish
There's the Red Indian Fish (Pataecus fronto), the biggest at just over 30 cm (a foot) in length. It comes in a range of pink, orange and red colours and is well disguised as a leaf or suspiciously leaf-shaped lump of sponge.

The Whiskered Prowfish (Neopataecus waterhousii) is almost identical except it reaches only 20 cm (8 in) long and has a collection of little warts on its chin.

Image: Geoff Rollins
Warty Prowfish
Finally, the Warty Prowfish (Aetapcus maculatus) has a vast collection warts all over its body. They're not disguised as any kind of leaf I've ever seen. More like some random collection of splodgy colours. That serves perfectly well as camouflage when you live in a coral reef or some other place that has a lot of random colours.

Camouflage and disguise are important for Australian Prowfish because they're ambush predators who sit back and wait for small shrimp to come close enough to snap up.

Image: Peter Southwood
Australian Prowfish are so good at staying still for aaaaaages that they get covered in algae, hydroids and bryozoans that encrust their skin as if they were a rock. Eventually there's nothing else for it and the Australian Prowfish simply sloughs off their skin like an old coat to reveal their shiny, new skin beneath.

Having said all that about their sedentary lifestyle, Australian Prowfish can in fact swim...

Sort of.

The problem with swimming is it's the kind of thing a fish does. But Australian Prowfish don't want to look like fish. So they compromise by swimming just like something that can't swim, swaying and lolling like a dead thing.

In a bid to retain their leaf disguise, Red Indian Fish swim like a drunk man walking home from the pub. They stagger to the left and stop when they bump into an invisible parked car. They stagger to the right and rest their head on an imaginary lamppost. All the while they show an unusual disregard for staying right side up.

Image: John Turnbull
Turns out they're less The Prow than they are the Drunken Sailor.


Esther said...

Dead leaves swim better than

Joseph JG said...

I know! I wonder how much actual effort they put into it?