Here's a quicky published in the UK: Originally aimed at Brit's
Of the hundreds of families and thousands of species of fish found in Tropical and Sub-Tropical seas
Only one particular family can boast the extremes: From the exotic to the morose...
Scorpaenidae
By Bob Whorton
The Family Scorpaenidae is both large and diverse comprising of at least 10 sub-families, 70 genus, 350 species and numerous subspecies dotted around the world. For reasons of space this article looks only at the cross section of members that are encountered by sport divers in tropical and sub-tropical seas…Conceived to promote identification and an awareness of potentially lethal fish.
The Common Lionfish: The perfect predator?
The species most commonly encountered on almost every dive are Lionfish of the genus Pterois. 'Pterois Volitans' and similarly 'Pterois Miles' are amongst the worlds most exotic fish found commonly on almost every reef throughout the Indio pacific.
Long feathery quills and sheer flamboyance ensure these species stay as the worlds most photographed of fish too.
The only noticeable differences between these two particular species are their habits; 'Miles' being more active during daylight and has no Papillae or antenna, 'Volitans' does. The markings of the Lionfish can be very intricate, and no two are identical, ranging from black through red irregular bands with white edges Noticeable is the difference in facial markings between the two species, 'Miles' having a much less intricate line pattern than 'Volitans'.
"Loud" you may think, but in a monochromatic world it provides total anonymity.
During daylight hours the common Lionfish can be found amongst the reef shadows, its large well-developed eyes shunning bright sunshine, sitting headfirst in appropriate hollows.
The common sweeper or glassfish constitutes a major part of the Common Lionfish diet; anywhere sweepers are; caves overhangs or wrecks Lionfish will be nearby. The Lionfish is a very cunning and intelligent predator and knows that trying to feed on sweepers during the day will end in conflict with their 'minders' the 'Red mouthed Grouper'. To off-set the risk of injury, individuals or groups of Lionfish gather at dusk to coincide with the passage of the small fish off to feed near the surface, and then at dawn when they return to their shelter. The 'Ghianis D' wreck in the Red Sea is one such place to witness what can only be described as a "Round-up", where as many as a dozen Lionfish will act as a team to herd the small fish into the reach of their mouths. On the reef the Lionfish spends ages stalking using its skirted pectoral fins to corner and trap its prey. The dorsal, pectoral and anal fins of the Lionfish are all venomous, each spine fed from a central poison gland attached to the fishes spine. Venom is delivered simultaneously in reaction to offending pressure. Lionfish rarely attack divers but will react defensively if cornered. The 'sting' delivered is proportional to the size of the fish, larger individuals are known to deliver a life-threatening dose. A well-fed specimen can reach 35 cm in length, found in depths of 1-50 M.
Pterois Radiata: Clear finned Lionfish or 'Fire Fish' is distinctly different from the common Lionfish in both appearance and habit, so different I find it strange that it was classified into the same genera. Radiata is considered much rarer than the common Lionfish, but again this is debatable as in some areas of the Red Sea and Maldives they out number the rest by at least 5: 1. The truth is that Radiata is a truly nocturnal species that remains well hidden during daylight.
The extended dorsal and pectoral fins have much less membrane attached to it; hence 'clear finned'. The rounded fringeless head, streamlined body with broader deep red banding on a red background set it apart from its cousin. Although 30% smaller than the Common Lionfish, Radiata' venom is no less potent, stings from this fish can be so painful they can induce anaphylactic shock and even death. Hunting techniques of Radiata are typical "Lionfish"; with the determination of a 'Terminator'. Radiata, when observed at night can be seen using its modified pectoral fins to 'tiptoe' around, thereby creating little or no pressure that may alert potential prey.
Another common species around Indian Ocean reefs is 'Pterois Antennata' or 'Spot-fin Lionfish,'
This species is an elaborate mixture of all of the aforementioned. In addition its pectoral skirt has blue iridescent spots; seemingly used to confuse predators who mistake the spots for the eyes of a much larger fish.
The plumage or extended fin membranes of the Lionfish begin to develop when the fish is no bigger than a fingernail, the growth out accelerating that of the body. The oversized spines giving it a deceptively cute appearance not unlike a feather star, in reality the tiny fish is growing up into its life long protection; allowing it an above average chance of reaching maturity amongst the hostile "fish eat fish" environment of the seemingly peaceful coral reef. Main predators of Lionfish Species are Moray Eels and Napoleon Wrasse.
To further enhance their hunting skills further Lionfish on several reefs in Egypt are now using divers to inadvertently assist them at night. As soon as someone enters the water with a torch they acquire an entourage of opportunists. It can be quite startling when one turns round to find 4 or 5 Lionfish right at ones elbow waiting to pounce on anything suitable that the torch lights up. This amazing adaptability furthers my respect of their obvious intelligence.
Scorpaenopsis: The true Scorpionfish are in the middle of the family, its diversity of members provides the transition from pretty to pretty ugly…
The common Scorpionfish, Sc. oxycephalus is the species generally encountered by divers sitting amongst or on top of coral heads. The body shape of this fish is similar to the common Lionfish but without the extended fin quills. Beginning just behind the broad head the pectoral fin is more fishlike, standing just proud of the membrane are the infamous poisonous spines. In normal relaxed mood the fins are folded back but once agitated the whole lot folds forward, locking into position. The well-developed pectoral fins are often spread out like a skirt, wrapping around the rocks to break up the fish's outline. Fleshy fronds further break up the body's outline and the regions of the mouth too. One of the most amazing things about this fish is its micro pigment cells in the outer layers of skin enabling rapid colour changes to suit its background, rendering it almost invisible and perfectly adapted to a life of predation by ambush.
Scorpaenopsis Diabola the Devil/bearded Scorpionfish is the largest member of the family reaching a length of around 40 cm. The body and head though very similar to oxycephalus but much broader and takes on a dusky colouration. Above and below the eyes are growths and indentations that give it its devilish appearance. The fleshy growths below the mouth are quite long and bushy giving the impression of a beard. The habits of this fish are similar to the common scorpion, but being able to swallow much bigger prey. Maybe due to its confidence in size and defences this fish tends to be more passive and wholly unafraid of divers: However…
Scorpaenopsis Gibbosa the 'Humpbacked' Scorpionfish is more often than not confused with the Stonefish, which is understandable, but it still has the same characteristic shape of a scorpion. Its stone-grey colouration gives it the appearance of a corpse, making it almost impossible to see in its chosen environment of coral scree and rubble. In contrast to the previous varieties the humpback remains one colour, relying totally upon ambush. The head of this fish is pronounced in a looking upward fashion with deeply set eyes and a bottom-hinged trapdoor mouth. The gill covers appear rigid and spiked. The well-pronounced hump on the fishes back is covered with what look like tiny hairs and the dorsal spines hinge upward from it. The pectoral fins are normally semi-folded to break up the outline on the scree, but once open reveal extraordinary flashes of colour. Yellow with blue &/or red circles, dots and stripes; not something you would readily expect to see on an otherwise drab fish. Maybe it acts to confuse prey passing overhead into momentary lapse giving the scorpion time to pounce. The camouflage of this fish is so good that even when you are looking at one, one blink and you can lose it again.
My tip, and this comes from experience, before you get down photographing one make sure that you are not hovering a few inches above three more.
Even with their formidable defence Scorpionfish form part of the food chain too; preyed on by Giant Moray and Napoleon Wrasse amongst others.
In West Africa Scorpionfish are considered just another food fish. I was to find this out first hand when walking into a ships galley one evening to find one of the local divers scraping the spines off one… "That’s a Scorpionfish; they kill…" I gasped.
"Tastes very good!" was the reply.
Synanceia Verrucosa the 'Infamous' Stonefish brings us to the ugly end of the spectrum…
The Stonefish has become almost a legend because of its invisibility and passive killing ability.
It takes a very exacting eye to spot one at all, in fact you have probably swam over hundreds!
The Stonefish becomes its most dangerous when sitting in shallow water on reef tops, making it prone to be stepped on. The majority of reported Stonefish stings throughout the world are caused by unsuspecting people treading on them; even wetsuit boots can offer little protection.
The Stonefish is almost 'Egg Shaped' when viewed from above, its tail-fin curled around and pectoral fins slightly spread to further break up its outline. Tiny 'hairs' all over the body hold particles of sand - enhancing a stone-like appearance.
Fully open the pectoral fins are marked in much the same way as the 'Humpbacked' Scorpionfish.
The long dorsal fin containing the lethal spines rises only to swim, or under extreme prejudice. The eyes are set towards the top of the head; complete with movable eyelids. The large mouth is set back producing a pronounced chin. The edges of the mouth have an alternate red & white marking, maybe to mimic a shellfish. Any inquisitive fish is swallowed at the speed of light.
Stonefish are still quite common, but due to the crazy antics of some dive guide’s, who actually pick them up for photographers they tend to shy away during the day, emerging at night in strategic positions. Needless to say one of the reported stings by stonefish included one such guide... shame that!
A further warning about stonefish: -
They may look clumsy and inert but they are very fast swimmers...
This ability should never be underestimated, upset one and "passive" goes right out of the window!
Poison and treatment
The toxic venom at best will cause excruciating pain that can be felt spreading from the effected area. It will also lead to paralysis and shock. If not treated quickly (especially with stonefish stings) the episode may prove even fatal. The important thing is to get out of the water "PRONTO" and seek immediate help and treatment. When no anti-venom is available (rarely is) the effected area should be immersed in very hot water to elevate the pain and cause the venom to clot before it can effect the working of vital organs such as the heart, brain and respiratory system. The venom is thick and stringy like the white of an egg, having similar properties it thickens in the same way on exposure to the hot water (like a poached egg).
Professional medical help must still be sought to remove the problem all together.
