They are the heavily camouflaged ambush predators everyone wants to see , but which is which ? Just how can you tell a scorpionfish from a stonefish , asks Simon Rogerson
Tassled scorpionfish , Scorpaenopsis oxycephala
Reef stonefish , Syanceia verrucosa
MARINEBIOLOGY
They are the heavily camouflaged ambush predators everyone wants to see , but which is which ? Just how can you tell a scorpionfish from a stonefish , asks Simon Rogerson
It ’ s the same old story . Post-dive , on a liveaboard , at a bar , in the resort , a fellow diver looks up from his screen and proclaims “ I ’ ve got a stonefish ”. I lean over to admire what is inevitably a picture of a beautiful but well camouflaged scorpionfish . Part of me wants to let them enjoy the triumph , but my inner pedant wins out . “ That ’ s a scorpionfish ,” I say with an apologetic smile . “ Oh ,” the diver replies . “ How can you tell ?”
In truth , whenever a diver finds a well camouflaged , bottom-dwelling fish , it usually turns out to be a scorpionfish .
Some reefs are thick with them , while the stonefish seems to be less numerous , or at least favours habitats less frequented by divers . Crucially , the stonefish is even more proficient when it comes to camouflage . To find one , you have to have very good eyes , be very lucky ... or extremely unlucky .
Still , it ’ s a good question . How can you tell apart two different types of fish that live by imitating the same reefs ? Both are cryptic ambush dwellers , both are equipped with potent venom ( more of which later ) as a defence mechanism , and both are members of the subfamily Scorpaeninae .
Ugly-beautiful thing
Consider the scorpionfish . There are many types ( we have two here in the UK ), but identifying them to species level can be difficult , even for experts . They vary greatly in colour and ornamentation , so sometimes individuals of different species may resemble each other more closely than those of their own subspecies . Differentiating them often requires knowledge of head spine patterns , distribution of fin rays and body proportions .
A large scorpionfish leaves its reef to actively hunt at night
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