It is well known that fish can bite, but the ability of certain fish species to defensively or aggressively incapacitate humans, predators and their prey through venom, electricity and sometimes random stabbings is certainly unsettling. Stonefish, lionfish, stargazers and needlefish are but a sampling of fish that may slice, stab or otherwise disable you through some of the most remarkable examples of natural weaponry that mimic scalpels, hypodermic needles and lances. In this list, we learn about the most unsettling ways well-armed fish might be out to get you in certain cases, or at least, how they may harm you if you are not careful to stay out of their way.
10. Stonefish, a Rocky Risk
One without reasonable friendliness might be called a cold fish, but being called a stonefish may be a worse insult. Stonefish resemble craggy, submerged rocks and possess piercing spines that inject deadly venom into anything or anyone stepping upon them. Since stonefish resemble rocks, one need not be careless to step on the stonefish, just walking in the wrong place at the wrong time. Stonefish possess deadly spines to protect them from a predatory attack, but are camouflaged to such a great level that humans do not get a “fair chance” to avoid stepping on the stonefish. Native to the coastal zones of the Indo-Pacific, Stonefish have 13 razor like spines concealed under ordinary looking dorsal projections that match the rest of the animal’s body wide camouflage.
The stonefish’s dorsal spines act like hypodermic needles, injecting venom that flows from ducts strategically placed to deliver maximum envenomation. The unnatural looking hollow spines have evolved a perfect, sharpened form to ensure tissue penetration and work in unison to give a disabling and potentially lethal dose to any victim coming into contact with the fish’s dorsal region. Fortunately, anti-venom formulas are not only available, but widely produced and frequently administered due to the pervasive risk of contact with a stonefish in warm water regions. Stonefish may weigh up to 5 pounds and exceed 1.3 feet in length. Five species of stonefish are known to science.
9. Nasty, Nasty Needlefish
Needlefish act like living lances and interact through an accidental approach in their deadly interactions with humans. Native to oceans worldwide with a length of over a meter depending on the species, needlefish are consumers of smaller fish, cephalopod molluscs and crustaceans. While needlefish do not purposely attach humans, their long, slender and bone reinforced “beaks” and rapid swimming speed have resulted in fatalities and serious, sometimes horrific injuries. Reaching a potential length of over 3 feet depending on species, needlefish have a disturbing habit of launching themselves out of the shallow water they inhabit whenever disturbed, often by lights or sound. Speeds of up 34 miles per hour have been reached.
Deaths have resulted from penetration of the human brain through the eye socket and stabbing through the heart. The phenomenon has been identified as a subject of medical interest and concern in an article by the European Association for Cranio-Maxillo-Facial Surgery describing the case of nasal cavity penetration by needlefish jaws where the injuries and penetration were far more extensive than the superficial appearance indicated. Surgical removal of the embedded needlefish jaws, which had broken off was required.
Named to suggest a life as ocean going astronomers, certain stargazers are armed and defended to the point of redundancy. Their twin defence system has two ways of inflicting human or animal unlucky enough to cross its path, even accidentally. Lying on the bottom of the ocean in temperate and tropical zones worldwide, stargazers are grotesque in appearance with a mouthful of teeth to capture their prey. Behind the opercles and above the pectoral fins are two sets of venomous spines which penetrate anything or anyone stepping on the stargazer, made more likely by its habit of burying itself in sand to conceal itself from prey.
If the spines do not make their mark, stargazers of the genus Astroscopus have a powerful but bizarre electrical organ that is made up of evolutionarily adapted eye muscles able to build up and deliver a potent electrical jolt to disable victims. The rotation of the eye musculature serves to attract the interest of the prey and then delivers a jolt at the same time. After being stunned by such a glance, prey can be more readily consumed. In other words, the saying “if looks could kill” comes true to a degree in this genus of stargazer. The other genus of electric stargazers, Uranoscopus, uses sonic waves through muscles to create electrical charges that can discourage predators from approaching or potentially disorient their prey. Stargazers are thus doubly equipped to defend against predators and uniquely adapted to capture unwary prey.
7. The Lunging Lionfish
Lionfish look beautiful but have the potential to inflict serious wounds coupled with a painful dose of venom through the massive array of spines protruding from their back. Native to the South Pacific, Indian Ocean and Red Sea, lionfish have become an ecologically disastrous invasive species as well as a danger to humans off of the Eastern United States and Caribbean. The lionfish is an active predator that uses its pectoral fins coral small fish before engulfing them in its gaping mouth but without the primary use of the spines, which is for defense, lionfish would be an easy mark for higher level predators. Lionfish venom is highly neurotoxic and comes from a pair of grooves in the venom delivering spines, which are the ventral, anal and dorsal spines.
The protein-based venom contains a neuromuscular toxin and a neurotransmitter known as acetylcholine, which delivers a suite of nasty symptoms including pain, breathing problems, profuse sweating and difficulty in moving. While fatalities are rare, great care is required to handle the lionfish, or the sheathes surrounding the spines will be pressed down in combination with a puncturing action, delivering venom into the wound. Due to their invulnerability to predators, voracious appetite and high reproductive rate, a burgeoning population of lionfish deplete native species and are subject to extermination campaigns to save the coral reefs.
Tangs, or surgeonfish are must consider species in any account of fish that may harm humans or other predators in unconventional ways. Gorgeous and deceptively ordinary looking in their shape as fish, tangs are slim, relatively gentle bony fish that have an actual biological version of a folding pocket knife built into the side of their body near the caudal fin. Surgeonfish can inflict deep wounds through attacks on intruders into their territory or through retaliation upon being carelessly handled by humans or other animals through their sharp, streamlined spines that swing out and deliver slicing injuries to the flesh.
Such wounds may require urgent medical attention and are capable of causing lasting damage to tendons, muscles and nerves. When not being used to defend the surgeonfish, the spines, which form the shape of a blade rather than a spine will lie flat, only to spring out in response to disturbance. An incredible variety of body types and alien looking forms are present among the ranks of blade tailed fish species, including the aptly named unicorn fishes, which boast a bizarre forehead projection, slim, brilliantly colored surgeonfish and the bizarre sailfin tang, with vastly oversized fins surrounding the concealed blade.
5. Venomous Sharks
Venomous sharks might seem to be too much, or at least a concept from science fiction. But Jaws was not as well armed as its smaller cousins, the various species of spiny dogfish, some of which are not only armed with razor sharp teeth but also boast venomous spines. The spines will pierce the flesh of careless predators, protecting the small and ungainly looking sharks from attacks by larger marine animals. The spiny dogfish species are among the most familiar sharks and yet, the possession of venomous defense systems is one of their lesser known defining traits. Looking like miniature tiger sharks, spiny dogfish overcome their small size by hunting in canine like packs, potentially numbering over several hundred strong. Through teamwork, the mini sharks overcome prey up to three times their own size, but remain vulnerable to the bites of larger predators.
Their need for protection is made sure to be met by their possession of sharp, venom bearing spines located just in front of their dorsal fin, which make for a nasty mouthful should a predator attempt to capture a dogfish as its next meal. In addition to dogfish, the bullhead sharks have venomous spines that make them a formidable and memorable target to predators. Despite their defences, dogfish are vulnerable to humans who can potentially overfish them to startling declines, exacerbated in part by the fact that these sharks have some of the longest gestation periods among sharks, or any animal for that matter, reaching 24 months, despite their small size.
4. Clown Loach
The Clown Loach could be called the king of loaches, for this heavily built loach dwarfs many other loach species at up to 12 inches, with a dorsally tall body shape and brilliant yellow and black stripes that make it a prime love affair of the aquarium hobbyist. The native of Asian streams and wetlands is also a dangerous fish, with nasty, knife-like blades made of fish bone that swing out from just below the eye sockets, appropriately termed “subocular spines”. Clown loaches, like many spined, venomous or otherwise spike equipped fish are gentle algae and shrimp eaters, using their soft mouths to forage in the substrate, but reacting in an instant to ensure their safety from potential aggressors.
Sharpened and sprung in an instant, the blades can prevent a predatory strike to the loach’s head from succeeding if deployed in time. The blades are anchored in fleshy webbing, and curve backwards, sickle-like and resemble thin, exceptionally sharp fangs protruding from below the loach’s eyes. But the defence mechanism that evolved to cut into the mouth of fish and predatory birds can also lend a nasty gash to the hand of the aquarist careless enough to touch the fish. Clown loaches grow quickly, and the larger the fish, the bigger the blade. Adding to the risk of injury is the fact that clown loaches have two blades, one on each eye socket, allowing them to inflict double damage simultaneously once activated.
3. The Wily Weeverfish
Not restricted to exotic locations, but found even in the shallow waters around the British Isles, weaverfish are small, look innocent but pack debilitating and potentially disabling venom in their dorsal fin spines and also the gill region spines. Measuring only 6 inches or less in length, the weaverfish conceals itself in the sand, lunging forward to capture passing prey. The light color of the weaverfish blends well with sand, while the scientific name element “viperens” alludes to the venomous characteristics of these bottom dwellers. The only body parts showing on a buried weaverfish may be its defensive spines and face, hiding the fish from prey but increasing the risk that an unwitting “threat,” especially a human may tread upon it.
Methods of avoiding envenomation that have been suggested include walking in a shuffling pattern, which may scare off weeverfish and allow the bather to avoid treading on their spines. Weeverfish have caused large numbers of swimmers to suffer the effects of venom injection, leading to a wide range of serious symptoms and potential complications. Massive swelling and temporary paralysis of affected lasting up to two weeks are common results of a weaverfish sting. Additionally, there is a risk of infection with gangrene and also respiratory failure stemming from infection occurring in rare cases. Loss of pregnancy as the result of a sting has also been reported in a medical publication.
2. Three-Spined Stickleback
The three-spined stickleback averages at about the size of a tadpole and resembles a minnow. Residing in shallow pools, weedy stream margins, lakes and even shorelines, the three-spined stickleback is a “tiddler” that might be mistaken for a minnow by small children scooping with a net. And that is precisely the danger posed by this fish, which have sharp, bony spines protruding in rows of three from their backs and one sticking out sideways from each pelvic fin. Three-spined sticklebacks present a nasty surprise to predators as well as humans, given that their spines flip outwards when the stickleback is provoked or alarmed. If a predator tries to attack a stickleback, it may not only get poked, it may get a mouthful of spines instead of an easy meal.
Furthermore, the stickleback’s body is lightly armoured to afford further protection against consumption. A careless squeeze may cause injury from the spines directly, which could break off after being embedded in the flesh, or give a painful cut. The two pelvic spines can be locked firmly into place in a highly mechanical switching motion. Infection, especially in organically polluted water is another potential risk posed by stickleback stabbings. While small and not likely to be seriously dangerous, sticklebacks are an example that the most unassuming and small animals may pose a danger to humans and should be handled with due care. Furthermore, stickleback spines are not only sharp, they can lock into place once extended to protect against attack and inflict greater damage by puncture upon contact with a potential predator.
1. Bullhead Catfish
Bullheads are a reason to watch your feet and gather the contents of your fishing net with great care, even in seemingly mundane locals such as a Canadian lake. Equipped with venomous spines, bullheads are small members of the catfish family that blend in perfectly with muddy bottoms but can deliver a potent and painful sting should they be stepped on or just handled carelessly. The spines in their dorsal and pectoral fins act as hypodermic needles through which venom can be delivered, causing pain that exceeds that of a bee sting and potentially lasts over a week with swelling and irritation to follow.
Surprisingly, bullheads pose a threat to humans even at their youngest age, with centimeter long fry being able to deliver a nasty sting. Touching a swarm of baby bullheads by putting one’s hand into the group out of curiosity could lead to the delivery of multiple painful, venomous stings. Like many venomous fish, the mundane appearance of the bullhead as being small and dull in color, there is no visual warning that may cause an inexperienced person to recognize it as venomous. The bullhead is a popular food fish despite having venomous spines, as eating the fish is not harmful as long as one can get past the capture process without getting stabbed. The risks posed by bullhead spines has led to their receipt of some peculiar nicknames, including “horned pout” and “barbotte”.