Scorpions

They are usually shown in pictures living and hunting in surroundings of pristine beauty. Colourful coral growths festoon rocky outcrops set in sparkling white coral sand. Sunlight beams down, shimmering through crystal-clear water. A worthy environment for the fantasy forms of many of the better known SCORPION FISH. But, in reality these highly decorative animals are more often found in areas with little coral, a muddy or otherwise silted bottom, and murky water which is laden with nutrients and suspended siltation – it is not apparent, nor important, which is which to the naked eye. The result is less than perfect visibility! Other favourite haunts may be found around the rotting hulks of sunken wrecks or sundry items of discarded rubbish. The whole picture can be truly dismal. But the fact is these desolate underwater wastelands seem to be the preferred habitat for many species of Scorpion fish.

It is not just the spectacular forms of the more ornate scorpion fish which makes them so fascinating to many, but the fact that these fish are poisonous, and some of them very dangerously so, which imbues them with a special kind of aura and respect. Predominant among these are the Lionfishes (Dendrochirus) and Firefishes (Pterois). The venom is produced and contained in glands below the base of the spines. The spines are grooved, and able to propel the venom with the efficiency of a hypodermic syringe! Once pressure is applied to these spines as they impale someone unfortunate enough to make contact, or something trying to bite and eat a Scorpaenid, the venom is forced up the spine and into the flesh of the victim. Dorsal spines are the major vectors of the venom, but anal and pectoral fins are frequently similarly equipped. Unlike their land based namesakes none of the fishy scorpion species have a sting in the tail! Recreational water sports participants and careless aquarium keepers fall foul of these gaudy fish from time to time, and will tell earnestly and dramatically of the excruciating pain they suffered. Immersion of the affected area in very hot water is a good first aid approach, but further medical attention is usually necessary to avoid the worst possible consequences.

Best known of the Firefishes to the fishkeeper is the Turkey fish (Pterois volitans). This amazing fish is highly ornamented with very long extensions from its huge spread of pectoral finnage, and the ridge of deadly spines comprising part of its dorsal fin. The coral-red banded body and spotted markings of the otherwise clear tail and anal fin combine to make a fantastic animal. Like other species of firefish, when threatened the Turkey fish will incline itself forward to project the spine-tips towards the threat, and reinforce the “dont touch” signal by rocking sufficiently to jab the spines menacingly towards the intruder. This action was mistaken as a friendly bow by one enthusiastic lady Turkey fish keeper, but when she came into contact with these spines while cleaning the inside glass of the aquarium a painful lesson was learned. She was hospitalised for a few days, during which time she experienced memory loss and halucinations until the pain finally left her.

The various species of Dendrochirus are generally said to be less potent, but from a personal experience of being stuck by a single spine from a juvenile Zebra lionfish I can vouch for the pain being far in excess of that from a bee sting! Species of this genus are often available to the hobby, and their modest size makes them ideal for the home aquarium. But do not be misled by the small size. The mouth is capable of extending to an astonishing degree, and the body is able to accept and ingest a prey which looks far too large to be at risk from this predator. The companion fish should be considerably larger than the Lion fish. Perhaps they are best accommodated in a species tank (?).

Less visually appealing, and far more lethal, are the stone fishes (Synanceia). These horrendously ugly creatures are masters at blending perfectly with their immediate surroundings, with nothing more than the eye looking remotely animal-like. Even that tiny part of the overall bulk of the creature is adequately disguised from view within the lumpy form of the Stone fish and difficult to detect. The venom from this species is intensely debilitating, and can be life-threatening. It exceeds the potency of the Petrois species, the venom of which is powerful enough to barely be withstood without lasting damage being suffered. While the Firefishes display a highly visible appearance with their array of elongated finnage, embellished with reddish stripes on a contrasting base colour, the Stone fish relies on being, in effect, invisible for its impressive success as a sedentary predator with a huge appetite to be satisfied. Accidental contact is, therefore, a constant threat to the unwary.

Another genus of scorpion fish contains some fantastic species too. These are the Rhinopias. Taken from their immediate surroundings they may be easily detected, but usually they have adapted to convincingly blend with their environment, and enjoy a similar benefit from stealth, like the stone fishes. Colour variations are accordingly quite normal. More spectacularly there is an ability to assume different forms of embellishment to both finnage and body texture to result in two fish of the same species looking quite different. Very occasionally specimens of these rarely found fish do become available to the aquarium hobby, when they are both highly prized, and highly priced! Most would agree that Rhinopias aphanes, sometimes known as the Weedy scorpion fish, is the most spectacular species. This incredible fish has a strongly upturned snout, and is usually found indulging in a strange rocking motion, which adds to its overall appearance as a clump of innocuous marine growth. The entire fish is liberally covered with extended cili, further advancing this deception. Any passing fish which comes within range of this harmless-looking piece of marine growth, apparently rocking back and forth with the surge, is likely to be sucked into the capacious mouth with a swiftness which is belied by the general demeanour of this otherwise sedentary fish.

A more frequently seen Rhinopias species is frondosa, which usually has less cili ornamenting the body and finnage extensions, but can occur in stunning colour variations. Purple-ish colouring is perhaps the most frequently seen, but a vibrant red form is a particularly striking variety occasionally encountered. This species has the same strongly upturned snout as aphanes. A close relative to the Rhinopias is the Ambon scorpion fish (Pteroidichthys amboinensis). This species is most often found in a camouflage colour of brown and black markings, with some white spotting, enabling it to blend well against the similarly coloured bottom territory it favours. Cili growths can be obviously whispy, or hornlike, or not prominent at all. This fish is not commonly found, and certainly never in numbers at any one site. It is rarely available to the aquarium hobby. I visited a comparatively new “muck diving” site in Bali recently and there was much excitement when we found a specimen which had enormous head horn extensions, and was a “reddish-purple” colour. Pictures of this fish have since been examined by experts in Hawaii, Australia, and USA, and there is no common concensus on its identification as yet. But the owner of the dive resort where the fish was found, Takamasa Tonozuka, says it IS an Ambon scorpion fish, and that will do for me until something more positive comes up from the present forum. It seems that two features are causing much of the controversy, and those are clear “windows” in the pectoral fins, and the enormous size of the head horn projections, well in excess of anything recorded for the species until now. A preserved specimen will be needed to ascertain the true identity, or declare it to be a new species to science and given a name. (I rather hope it will never be collected and pickled for that purpose).

The Devil scorpion fish (Inimicus species) are generally unlovely and unloved fish, only occasionally coming into the hobby market. This is another highly variable fish as far as its basic colouring is concerned, and can be stark off-white in areas of white coral sand bottom, or a distinct red colouring where this gives more appropriate protection. Most often, however, they are found garbed in a suitably sinister blackish colour. For these are another species equipped with a powerful venom, and in many ways almost as hazardous as the Stone fish. Although it does not share the amazingly unfishlike camouflage of the Stone fish, this species is most often buried unseen JUST beneath the surface of the silt or mud of its habitat. A hand or knee casually placed onto the patch where it is concealed will take the full force of the injected venom from the robust dorsal spines, which are knobbly and not easily removed if stuck deeply into the flesh of a victim. This burying habit makes the Devil scorpion fish an unwelcome inhabitant in a reef aquarium, where its activity is likely to be disruptive to the decor. Anyway, it is no beauty, but tends to be regarded as grotesque by most. The otherwise bland colouring is relieved by bright patches of the central areas of the pectoral fins when they are spread in fright or threat These patches may be anything from creamy white to a fiery red.

The various scorpion fish are all predators which search for live prey, or snatch them as they pass. In the aquarium they have to be trained to accept dead foods. They quickly learn to do this by example when put with existing “trained” fish, but newly acquired fish without a mentor may need to be tempted with dead fish or other fresh sea food item being wiggled at the end of a pair of aquarium tongs. Initially they may be too scared of this alien instrument to approach the morsel being offered, but this fear will soon pass – and all the more quickly if the tongs are left in the aquarium between the feeding attempts so the fish become accustomed to them. Once the first dead fish has been taken the battle is usually won, and soon the fish will rise to the surface to snatch the food as it hits the water. But captive scorpion fish have something of a reputation for going off their food and even regressing to complete starvation as a result. The key to avoiding this scenario is to ensure the diet is varied as much as possible. It is tempting to give the same food to the fish routinely when it is known that a particular item is favourite, but it is not good practice. The diet should be as varied as possible to deal with possible refusal of one key item at some stage.

It was an interesting experience to be greeted at one dive site in Mabul, Sabah, by a group of between three to five large, fully mature, Turkey fish on every night dive. Once the dive lights were spotted they made a bee line to the lit area. Their interest was to benefit from their prey fish being spot-lit for them, and to lunge in and snatch the unsuspecting “sleeping” diurnal species while they were immobilised by the sudden flood of light. Efforts to shoo them off were completely unsuccessful, and they would swim quite as fast as the divers could fin away in an attempt to shake them off. It was quite disconcerting to be poised to take a picture of a fish and find a huge turkey fish brushing past your hand and face to strike at the subject with amazing speed and deadly accuracy. But they were also seen to hunt as a group sometimes, and seemed to have some sort of pre-arranged pecking order. With their pectoral fins spread widely they converged on the prey, effectively blocking any escape past this menacing barrier, but only one would attempt to make the “kill”, leaving another to move in for the next catch. Sheer opportunism, used to great effect, but an irritation to the divers involved.

Scorpionfish in the aquarium are only a threat to other fish small enough to fall prey, and tasty invertebrates, like shrimps, crabs, or other mobile occupants of a reef tank. But the sessile invertebrate life in the reef aquarium will be totally safe from damage by these interesting fishes. They may be more often found in mucky sites in nature, but thankfully such conditions are no pre-requisite for their success in aquarium culture. They will enhance an already beautiful background aquascene in a home marine reef aquarium to great effect. Because of their generally sedentary nature they are quite undemanding as aquarium fish. But they DO sting, and great care must be taken when they are being handled during any necessary moves. Care has to be taken when carrying out routine in-tank maintenance. They very, very rarely actually approach to attack with their spines. These are essentially defensive weapons. But that said, it is not entirely unknown for an aggressive approach to be made towards an intruder!

Tailpiece : In a shop environment I one had a large frogfish which, although generally quite static, I thought should have a larger aquarium. It was put in a tank with adult Pterois radiata firefishes. One morning we found the frogfish with just the tips of a firefish’s spines sticking from its mouth, and it eventually swallowed the whole fish. But it appears the venom was not injected, as the frogfish digested its gorged meal, and went on to live many another day!

The Twinspot lionfish (Dendrochirus biocellatus) is spectacular with the prominent eye-spots on its soft dorsal fin, elongated labia from either side of its mouth, and banded pectoral finnage. It is also a most elusive fish, quick to scurry into nearby cover when disturbed.

The “regular” form of the Ambon scorpionfish (Pteroidichthys amboinensis) can be quite variable. The specimen pictured here could be regarded as a good example of the form most often encountered.

The Devil scorpionfish (Inimicus didactylus) is hideously ugly, but at least this unusal red form has the benefit of attractive colouring. The species is more often found in dull, blackish forms, littered with silt . (Note the extended rays of the pectoral fin, forming claw-like appendages with which it pulls itself along the bottom).

In the Red Sea Firefish are frequently represented by Pterois miles, which has most elaborate antennae and labial extensions from the corners of its capacious mouth. This is a view of the Firefish no small fish will want to see!

Russell’s firefish (Pterois russelli) is an infrequently found species. It might easily be overlooked and mistaken for the more common Turkey fish, The most easily recognised distinguishing feature is the lack of spotting in the soft dorsal, tail, and anal fins.

When the Turkey firefish (Pterois volitans) is hunting across the sea floor at night its dorsal spines are inclined forward in a threatening pose, and the pectoral fins are partially spread ready to be thrust rapidly forward to confuse any escape attempt by a cornered prey.

This intensely coloured scorpionfish is either a Weedy scorpionfish (Rhinopias frondosa) or an Eschmeyer’s scorpionfish (Rhinopias eschmeyeri), and at present there is dissent between experts as to which this one truly is. Because of the variability of both colour and body form a specimen would be needed to be properly examined in order to to come to an informed decision.

The Weedy scorpionfish (Rhinopias frondosa) is found in a variety of colours, but this intense purple colouring is particularly unusual. A pinky- mauve is a more usual colour form. This frondosa was found in close association with the red specimen, further complicating the positive identification of that fish.

Right, find the fish! You need to locate the eyes (just above the centre of the picture), then travel downwards to find the arc-shaped lip of the mouth. There is nothing more in the picture which will identify the Stone fish (Synanceia verrucosa) as it lies unseen within a rocky niche, deadly poisonous dorsal spines ready to deal with anything crazy enough to try and attack or disturb it.

This scorpionfish is another controversial specimen, which at first was thought to be most certainly a form of the Ambon scorpionfish. But the clear “windows” in the pectoral fins (seen here widely spread) are not typical of that species. However, in all other visual respects it would be accepted as Pteroidichthys amboinensis, and it most probably is! The Weedy scorpionfish is one of the sea’s weirdest creatures! The strongly upturned mouth has the same voracious appearance as those of the other species in this genus. It also gently rocks back and forth in the same manner. The body outline is broken with many lumps, bumps, and cili, and together with its ability to assume appropriate colours it is perfectly concealed, blending with its immediate surroundings.

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