From poisonous marine creatures to fish that pack a powerful bite, here are 9 small fish
that do serious damage: Number 9 Boxfish
Boxfishes may be small but that doesn’t mean they’re easy prey.
In fact, few marine predators can actually eat adult boxfishes.
This is because, whenever threatened, these fish can secrete toxins from their skin which
act as a chemical defense mechanism.
The mucus secreted from the skin of some members of the boxfish family contains pahutoxin,
a water-soluble, crystalline chemical toxin.
This is unique among known fish poisons and can break down or destroy red blood cells.
When the toxic mucus is released, it dissolves quickly negatively affecting fish in the surrounding
area.
Pahutoxin can be deadly for various biological systems and even other boxfishes aren’t
immune to it.
Number 8 Acanthuridae The Acanthuridae family contains more than
86 extant species of unicornfish, tangs and surgeonfish.
Many of them are brightly colored and therefore a popular addition to aquariums all over the
world.
These marine fish typically inhabit tropical seas and they’re most common around coral
reefs.
Most Acanthuridae species are small with lengths of 6 to 15.5 inches.
One distinctive feature of the family makes these fishes quite dangerous.
On either side of the tail, they have scalpel-like spines which are extremely sharp.
These naturally-evolved switchblades can act as a defense mechanism against potential intruders.
Some species have additional features that make them even more dangerous.
The striped surgeonfish, for example, must be handled with extra care as its caudal spine
is venomous.
Number 7 Red Lionfish Lionfish are known as fish that can do serious
damage because of their venomous fin rays that deliver painful puncture wounds.
The venom is quite potent and, on rare occasions, can be fatal for humans.
These fish are easily recognizable by their zebra-like stripes, enlarged pectoral fins
and elongated dorsal fin spines.
Whenever the lionfish feels threatened it will spread and present its fins before attacking
with the dorsal spines.
One common species is the red lionfish, which grows about 12 inches long and features red,
white and brown stripes on its body.
The red lionfish has been designated as an invasive species in the Mediterranean Sea,
Caribbean Sea and the West Atlantic Ocean.
The lack of natural predators has enabled the red lionfish to basically decimate local
reef fishes in the regions it inhabits.
For humans the symptoms of lionfish envenomation include extreme pain in the affected area,
nausea, dizziness, headaches, fever or breathing difficulties.
In rare cases it can cause temporary paralysis of the limbs, heart failure and even bath.
Number 6 Piranha No list of dangerous fish is complete without
the blood thirsty piranha.
There are over 60 piranha species found in river systems ranging from northern Argentina
to Colombia.
Piranhas have deep bodies, saw-edged bellies, blunt heads, incredibly strong jaws and razor-sharp
interlocking teeth.
Most species rarely exceed 2 feet in length.
During the dry season, when the water is low, groups of piranhas called shoals converge
in feeding frenzies to take on large prey.
These groups can sometimes consist of more than 100 piranhas each charging in to tear
a chunk of flesh off their prey.
Piranhas are also known to be attracted to blood in the water.
Attacks on humans have occurred most notably in Brazil, Bolivia and Argentina.
In 2011, a drunken teenage boy from the town of Rosario del Yalta, in Bolivia, jumped out
of a canoe into a piranha infested river.
The teen was almost eaten alive and later died from excessive bleeding.
Number 5 Pufferfish Also known as blowfish or balloonfish, pufferfish
are among the most poisonous vertebrates in the world.
There are around 90 species in the Tetraodontidae family and most of them are small to medium
in size.
They’re found in warm and temperate regions around the world, usually in the sea but also
in brackish or fresh water, in some cases.
They’ve several defense mechanisms.
Pufferfish have excellent eyesight and can use their tail fins as rudders to generate
sudden bursts of speed.
Their best known adaptation for survival is its ability to fill its highly elastic stomach
with air or water until the entire fish becomes almost spherical in shape.
Pufferfish have sharp spines all over their body and these become visible when it’s
inflated.
Predators that catch the pufferfish before or during inflation may choke to bath.
However, the most important defense mechanism is the tetrodotoxin, or TTX, which can be
present in its liver, ovaries, intestines or skin.
For people, this neurotoxin can be deadly.
Poisoning symptoms include vomiting, dizziness as well as numbing and prickling over the
body.
It’s followed by decreased blood pressure, rapid heart rate and muscle paralysis.
As the diaphragm muscle becomes paralyzed, the victim stops breathing.
Number 4 Stonefish The stonefish is one of the most venomous
fish known to man.
These creatures live in mud flats and estuaries among rocks or coral formations in the coastal
regions of the Indo-Pacific.
The stonefish draws its name from its appearance which seamlessly blends with the fish’s
surrounding environment.
They’ve thick bodies with large heads and mouths and bumpy skin covered with wart-like
lumps and fleshy flaps.
When resting, unmoving on the sea floor, it’s very difficult to detect.
Swimmers who don’t notice these creatures may inadvertently step on them, which can
trigger a painful and even deadly sting.
Glands which are located at the bottom of the fish’s dorsal fin spines secrete potent
neurotoxins.
As the swimmer steps on it, the fish may inject a quantity of venom that’s proportional
to the pressure applied to it.
Stings may also occur on beaches, as these fish can live out of water for up to 24 hours.
An additional defensive feature was revealed by a 2018 study.
According to the report, stonefish can extend a lachrymal saber, which is a sharp specialized
spine, whenever they feel threatened.
If left untreated, the sting of a stonefish can be fatal.
Hot water and vinegar should be applied to the affected area, followed by immediate treatment
with anti-venom.
Number 3 Stargazer The stargazer has been called ‘the meanest
thing in creation’.
In addition to their terrifying appearance, some species can deliver venom as well as
electric shocks.
Stargazers draw their name from the fact that their eyes are placed on top of their heads,
as if they’re ‘looking at the stars’.
They can be found all over the world in deep and shallow salt waters.
Stargazers have massive heads, large upward-facing mouths and their bodies can grow to almost
3ft, for the giant stargazer.
Their killing technique relies on ambush and they have weapons in their arsenal that can
cause some serious damage.
Stargazers camouflage themselves in the sand and leap upwards to ambush prey.
Some species have a worm-shaped lure, that grows out of the floors of their mouths and
which they can wiggle in order to attract prey.
Above their pectoral fins, stargazers have two large venomous spines.
Stargazer species from the Astroscopus or Uranoscopus genera can also deliver electric
shocks, in addition to venom.
All these vicious adaptations are why stargazers are sometimes known locally as the ‘mother-in-law
fish’.
Number 2 Candiru Also known as the toothpick or vampire fish,
this parasitic catfish is native to the Amazon Basin and found in Ecuador, Peru, Colombia,
Brazil and Bolivia.
The smaller candiru species are known for their tendency of invading and parasitizing
the human urethra.
Once it enters the passage, the candiru erects the short spines on its gill covers and may
cause inflammation, bleeding and even bath to its victim.
One report from the 1800s, talks about a Brazilian physician who examined several male patients
whose penises had been amputated following parasitism by candiru.
In 1891, naturalist Paul Le Cointe describes an incident involving a candiru that became
lodged in the vaginal canal of its victim.
Le Cointe removed the candiru himself.
First he pushed it forward to disengage its spikes and then turned it around and took
it out head first.
One of the most persistent reports about the candiru defies the laws of simple fluid physics.
Some locals from the Amazon Basin claim that it’s dangerous to urinate in rivers known
for the presence of candiru.
It is said that the fish can jump out of the water and ascend the length of the you're
in column to enter the urethra.
Even though fluid mechanics makes this impossible, it remains one of the most common myths regarding
the candiru.
Number 1 Sheepshead This deep-bodied flat fish is commonly found
on the Gulf and the Atlantic coasts of North America.
The sheepshead has a silver body with 5 to 7 broad, dark vertical bands.
It has a short mouth, finely serrated scales and sharp dorsal spines.
The sheepshead can reach 35 inches in length and weigh more than 25 pounds, although such
proportions are rare.
The most unusual aspect about this species is its dentition which is eerily similar to
that of human beings.
Its front teeth resemble human incisors while its back teeth look like human molars.
This dental pattern enables the sheepshead to crush and grind its prey.
It can chew through heavily-armored prey like echinoderms, oysters or barnacles.
The sheepshead is also quite cunning as it’s known to steal bait from fishing hooks.