The ocean is full of weird creatures, from a sea slug that's part vegetable to a venomous three metre-long worm. So it shouldn't really come as a surprise that there are a bunch of fish who have evolved to emulate their surroundings – with some truly odd results.
The camouflage abilities of these fish make them excellent ambush predators – but some also possess extra qualities, including highly venomous toxins. Can you spot these fish in their natural surroundings?
Fish that look like rocks
Scorpionfish
As the name perhaps suggests, scorpionfish have a deadly 'sting' in the form of spines which are coated in a venomous mucus. While not toxic enough to kill a human, a spine from one of these is still extremely painful.
Scorpionfish tend to live in reefs but can also be found in estuaries, bays and lagoons. Their mottled colour (as well as skin flaps, in some species) means they can blend in well with rocks and reefs. Scorpionfish spend their daylight hours resting and hunt at night.
Painted frogfish
There are around 60 species of frogfish, but the painted frogfish has a rather unique way of disguising itself: wart-like protrusions and eye spots that mimic sea sponges.
Its colouring varies hugely as it tends to match its surroundings. Frogfishes have the capacity to change colour within a few weeks, from white to black, with several shades such as pink, orange and red in-between.
Stonefish
The stonefish is often regarded as one of the world's deadliest sea creatures due to its venomous dorsal spines which release verrucotoxin (VTX) – and can be fatal to humans if left untreated.
Their danger predominantly lies in their ability to totally disguise themselves on the seabed, and unsuspecting swimmers can brush their hand against them or even step on them. Stonefish are capable of staying completely still and wait to strike out at passing prey.
Read more
- World's deadliest places for wildlife: You may want to take extra care if these places are on your visit list...
- Severed spinal cord, suffocation, heart failure – what's the worst way to die from a wildlife encounter?
Camouflage grouper
So-called for obvious reasons, the camouflage grouper has blotchy skin in order to help it hide in lagoons and outer reefs. It also likes to swim through caves and crevices which further helps disguise it. It mainly feeds on crustaceans and occasionally cephalopods and gastropods.
Stargazer
Stargazer fish – named after their eyes that point upwards 'to the stars' – spend most of their time buried in the sand to avoid predators and ambush prey swimming above. Their brownish hue allows them to blend in to their surroundings and their pectoral fins act like shovels as they bury their bodies under the substrate.
Angel shark
For an angel shark, disguising itself on the seabed means that it expends very little energy. It lies in wait, with only its eyes visible, for unsuspecting prey to swim by.
However, unlike the other fish on this list, scientists have discovered that the Japanese angelshark is able to conceal its breathing and gill motion – making it even more inconspicuous on the seabed.
- Fish can do maths, walk, fly AND pee: fish facts that will leave you scratching your head
- Meet the mysterious olm – a weird and extremely rare cave-dwelling predator nicknamed the 'human fish'
- "So weird. So unreal”: diver films fantastical creatures crawling along seafloor
- There's a peculiar fish in the Venezuelan mountains that climbs boulders with its mouth – and biologists are obsessed with it
Main image: whitemargin stargazer. Credit: Getty