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Puffer fish is known for having a anti-predation defense mechanism of having toxin-exuding spikes.
Are there predators which evolved specifically to prey on puffer fish? (presumably, by evolving immunity to the toxin)?
I know that sharks eat them, but I doubt sharks evolved to be immune specifically to puffer fish toxin, since their evolutionary development preceded puffer fish's.
Wikipedia has some revealing information here:
Not all puffers are necessarily poisonous; Takifugu oblongus, for example, is a fugu puffer that is not poisonous, and toxin level varies wildly even in fish that are. A puffer's neurotoxin is not necessarily as toxic to other animals as it is to humans, and puffers are eaten routinely by some species of fish, such as lizardfish and tiger sharks. Also, Japanese fish farmers have grown nonpoisonous puffers by controlling their diet.
It seems that susceptibility to tetrodotoxin varies a lot from one animal to another, and so some natural variation might allow a reasonable amount of predation to occur. I also wonder whether the variation in the amount of toxin in the fish implies that the fish are often depleted.
There are cases of animals who have evolved a resistance to Tetrodotoxin, but for the most part its may the predators you are thinking of. The toxin is synthesized by a symbiotic bacteria and is found not only in fugu but also blue-ringed octopus, rough-skinned newts and some sea slugs. These animals probably all began with enough intrinsically low sensitivity to the toxin to take on the symbiont and probably evolved to be completely insensitive. To find a predator that would have co-evolved a similar resistance you would look for a predator that particularly favors the envenomed animal. In the case of the rough skinned newt, its suspected that the common garter snake is an example of such co-evolution. Others may be out there to discover - its probably difficult to watch marine animals to know what their typical predators are.
Are there predators evolved to eat puffer fish? - Biology
Science note, avian dinosaurs are birds, non-avian dinosaurs are what regular, reasonable people call dinosaurs. They went extinct when a comet or asteroid hit earth about 66 million years ago. I will call non-avian dinosaurs, simply dinosaurs for the rest of this webpage.
Of course, it would be far easier for scientists to bring back the woolly mammoth than the dinosaurs, so as long as you do not see any really hairy elephants you are very safe. Nevertheless, just in case, here is my advice, based on the experience of my friends and relatives, and the standard advice of the experts on how to avoid being eaten by today's predators.
Predatory Dinosaurs Like Today's Predators?
If so, encounters with dinosaurs might be much less dramatic than Jurassic Park-Jurassic World movies suggest. There are about a million warm blooded predators in the United States and Canada that are large enough when full grown to eat an adult human. There are also over a third of billion humans in the United States and Canada who frequently hike around in the wild with no protection against these predators. Yet only three to four people per year are eaten in the average year.
Coyotes are too small to eat adults, but not little children and surely these coyotes have many opportunities to attack and kill little children, but only one child has died this way in the last several decades. Lots of dogs and cats, probably millions, but only one child.
So if dinosaurs acted like our present predators close encounters between dinosaurs and humans might be much less bloody than the movies.
Given, as I said above, there are about a million mammalian predators in the United States and Canada that when full grown can kill an adult human and millions of coyotes, tens of thousands of which live in cities, that could kill our little children it might be useful to understand how to avoid be eaten by them while we wait for the unlikely event of a dinosaur attack.
Apparently bears are concerned with dental hygiene. Which I guess is understandable given that they do not have dental insurance and it would be difficult to collect enough berries and insect grubs to pay a dentist. Perhaps Smokey the Bear has a new slogan, "Only you can prevent tooth decay." So if they actually do create a real world Jurassic Park you should bring toothpaste just to be safe. A close friend of mine who frequently goes camping and has friends that do also confirms that the bears love toothpaste.
My close friend also confirms that the bears are getting cozy. One of her best friends, whom I also know, was having breakfast while camping with her family. A bear invited itself to their breakfast and in the process brushed up against her. She was so flustered she spilled coffee on the bear. The bear took it well. There was no lawsuit, surprising for California, and the bear did not even growl. The bear was mellow, it ate breakfast and left.
As mentioned above bears love toothpaste, but they are also fond of paintballs used in paintball wars. There is a Canadian resort called Whistler that has lots of bears and paintball wars. The paintballs are made so that the wildlife like to eat them. That is the clean up plan. When the horn sounds to start the paintball war the bears consider it a dinner bell. Children shoot each other with paintballs, bears eat paintballs but not the children. Apparently the Russian cartoon "Masha and the Bear" is more realistic than Jurassic Park/World.
Do not run is perhaps the most common advice for dealing with predators, and no doubt good advice based on a lot of experience. But while the advice is good, the reasoning that is given to justify it makes little sense.
It is argued that running activates the hunting instinct of the predator. I suspect that hunting instinct of a predator is activated by hunger and is usually active. Our objective is to activate the don't eat anything that you do not know is safe to eat instinct. If the predator is going to survive long enough to reproduce this has to be a powerful instinct and this is what keeps us safe.
If an animal does not run it is usually dangerous to eat, for example, rattlesnakes, cobras, and other venomous snakes. In the wild standing your ground is a sign that you are not safe to eat. As the bear has never eaten a human before, we would have killed it if it had, bears very rarely will want to risk eating a human who stands their ground.
Give Predators Space
The bear may have seen the situation as similar to what we have seen on nature documentaries. Predators growl and threaten one another as the try to control the carcass of an animal one of them killed. The bear may have been saying, this is my garbage can, get your own. I am speculating on this, but it seems safe to say that, while you do not want to run away it is best to give bears and no doubt predatory dinosaurs their space. Three or four feet is too close.
Nevertheless, in our national parks campers and bears seem to coexist in surprising proximity, as the experiences of my relative and friends illustrate. This seems to be a growing trend, but if we go back far enough there was an even cozier relationship. People used to feed black bears by hand, with nothing between them and the bears. This resulted in occasional mauling, and was suppressed because it was dangerous for the campers. But most of time the humans were not mauled because the feeding persisted for quite some time.
In spite of this, I do not recommend feeding large predators by hand with no protection. Black bears are not teddy bears, and predatory dinosaurs were not Barney the dinosaur.
Don't Do Anything Dangerous to Escape
Actually bears frequently charge, but rarely actually attack. After all, only three or four people are killed by large mammal predators in the United States and Canada in the typical year. So jumping off a cliff into water of unknown depth is not a good bet. When you face a predatory dinosaur do not assume that an attack is certain. Do not do anything very dangerous to escape.
Out in the Woods, Under the Sea
Environment and Experience
If the predator had grown up in Jurassic Park or Jurassic World and mostly ate sheep, goats, and cattle, it might be very familiar with humans but it would never have eaten them. So from the predator's point of view humans are around all the time and the humans are not particularly afraid of them, so humans are probably not safe to eat. As argued above, if an animal does not run away it usually has some way to defend itself.
Easy to Catch, Deadly to Eat
But even animals that are not toxic can be dangerous to eat. There are porcupines that have quills that can work their way into a predator and kill it. Even skunks could be dangerous. The stench they leave on a predator could warn potential prey and make it difficult for the predator to hunt. By the time the stench wears off the predator might die of starvation.
So there are a lot of animals that might look like defenseless prey, but that are quite dangerous to large predatory mammals. Eating anything that moves would almost always kill the predator long before it was able to reproduce. As surviving and reproducing is what evolution is all about large predators on land have evolved to be selective and careful.
The same can be said for animals in the ocean, it is estimated that ten percent of all species of fish in the ocean are poisonous, it is probably higher than ten percent for the invertebrates. So on both land and sea the predators need to avoid eating prey they are not familiar with. If a predatory fish, whale, or seal sees something that it is unfamiliar with and furthermore it looks weird and swims slowly it is probably toxic or otherwise dangerous to eat. Lucky for us, we fit that description perfectly.
The Exception Proves the Rule
Don't Trust the Crocs
Heart Attacks Kill More Than Bears
So a key safety tip, perhaps the most important safety tip is do not do anything dangerous or avoid anything healthy because of a completely unrealistic fear of predatory dinosaurs, or a largely unrealistic fear of today's large predators. Large mammal predators only eat on average one out of every hundred million Americans and Canadians in an average year.
The people who wish to introduce bears, particularly grizzlies complain about these jokes, claiming they are not funny. Actually, they are funny, but humor is not necessarily a good guide to safety.
A better response might be to compare human bells with a rattlesnake's rattle. By making noise including wearing bells we are warning the bear that we are dangerous, just as a rattlesnake warns potential predators to eat something else. By making noise you make your presence obvious, which is something that defenseless prey would avoid. The noise warns the bear that you are dangerous to eat, which you are because humans will usually kill the offending bear and any other bear or potential predator in the area.
It has been suggested that perhaps instead of bells we should carry rattles that sound like rattlesnake rattles. Perhaps. This would be an interesting experiment for the experts and then possibly an interesting business opportunity for some businessman. If it worked on the bears and mountain lions it would have the advantage that people could easily understand why it worked and would be more likely to use it.
As a teen I went to a camp, which had a farm next to it. We were chatting with the farmer's wife and she said that in one of the last few nights a mountain lion had attacked their horse. They came out and scared the cat off. It occurs to me that even with an umbrella I would not look as large as a horse.
On the other hand the umbrella would look weird to the predator, sort of like a puffer fish blowing its self up. It is generally argued that puffer fish blow themselves up so they will be too big for the predator to eat. I figured that the real reason that puffer fish puff up was to warn predators that they are very poisonous to eat. I later saw a video that started with the standard explanation about being too big, but they added my explanation, the poison warning.
Opening that umbrella while you stand your ground may make you look weird and weird things that stand their ground are often poisonous, venomous, or otherwise dangerous to eat, like puffer fish, or cobras spreading their hood.
Why Its Counter Intuitive
As our strategy of warning predators from bears to sharks seems to work well there is a fair chance that it would work with dinosaurs too. In our movies we are using dinosaurs not because they would be more dangerous but because we know that today's predators are pretty tame so to create exciting fantasy we have to use yesterday's, or perhaps I should say yesterera's predators, to keep up the excitment. Here are some other biology pages. In many of these pages I use the same principles I have used concerning whales. For example, I use similar reasoning to explain why quetzalcoatlus, the giant pterosaur from the late cretaceous was the last of the pterosaurs. Biology Index
Are Puffer fish poisonous to touch or eat? Yes. Almost all pufferfishes contain tetrodotoxin, a substance that tastes fun to them and is often fatal to fish.
To humans, tetrodotoxin is deadly, 1,200 times more toxic than cyanide. There is one piece of toxin large enough to kill 5 adult humans and it has no antidote. This article will be finding the truth on is Puffer fish poisonous?
Are Puffer Fish Poisonous?
Tetrodontid is a family of primarily marine and estuarine fish sequences, most pufferfish species are poisonous and some are not. Not all puffer is necessarily toxic. Pufferfish are considered to be the second-largest poisonous spine in the world. (First prize goes to Colombia’s tiny gold poison frog).
Fugu fish Japan is a deadly puffer fish served in Japan. The Japanese eat 10,000 tons of fish every year but it can cost $ 265 per kg.
Is lungfish poisoned by touch?
In most puffers, they are hidden until inflamed, while the porcupinefish has an outer spine that is always visible. In addition to this ability, many species of puffer fish carry tetrodotoxin, which is the deadliest poison found in a spinal cord. This toxin is 1200 times more deadly than cyanide.
What if you touch a puffer fish?
If a fisherman catches a puffer fish, they will never touch the spikes because they are extremely toxic to humans and animals. However, if an animal manages to eat puffer fish, it is often poisoned by spikes or by poison when the puffer comes out of the fish’s limbs after dying.
Can you eat a puffer fish?
Poison in a pufferfish is enough to wipe out 30 people, and no antidote is known, yet many eat it. Known as fugu fish in Japan, pufferfish meat is an extremely valuable food prepared by specially trained, licensed chefs.
Is puffer fish poisonous in Florida?
Almost all puffer fish contain tetrodotoxin, a substance that makes them taste bad and often deadly. To humans, tetrodotoxin is deadly, 1,200 times more toxic than cyanide. In Japan, the meat of some puffer fish is said to be a taste – Fugu is called ugu
Can a Puffer Fish Sting Kill You?
A hunter who manages to snatch a puffer before it is inflamed will not feel lucky for long. Almost all pufferfishes contain tetrodotoxin, a substance that tastes fun to them and is often fatal to fish. … One person has enough toxin in it to kill 30 adult humans and has no antidote.
How do you die from puffer fish?
Fugate’s internal organs, especially in the liver, ovaries, eyes, and skin, contain severe amounts of tetrodotoxin. Poison, a sodium channel blocker, paralyzes the muscles while the victim is fully aware The poisoned victim is unable to breathe and eventually dies of shortness of breath.
Which part of puffer fish is toxic?
Other concerns are fish poisoning. Tetrodotoxin is found in several of the silver-cheeked toadfish organs, including the ovary and liver. When purified, this powerful neurotoxin can kill an adult man by dosing at about two milligrams.
Can you die from a puffer fish?
And make no mistake, people are killed by fungus poison. About five people make puffer fish their last meal a year, and many more become seriously ill. This is not a pleasant way. Tetrodotoxin, the poison, is actually produced by bacteria that allow fish to colonize different parts.
Can a puffer fish bite you?
Mushroom meat is not a community fish, they must be kept alone because they are carnivorous. “They can either eat small amounts of other fish or if they are too big to eat, they will bite on other fish’s wings,” he said.
How long does it take to kill you?
After eating the poison, it will take less than sixty minutes to get your respiratory treatment, which is your only hope of surviving the effects of this powerful poison. How long does it take you to kill poison fish? Anywhere from twenty minutes to twenty-four hours.
Some interesting information about pufferfish and their toxins
Pufferfishes are a common sight here in Koufos I don’t think I’m going to dive here without seeing at least one and usually several. There are two commonly encountered pufferfish: guanofail pufferfish (Aerothron melligris) and porcupine pufferfish, in which two species are found locally – Longspine Porkkeepinfish (Dydon holocanthus) and Spot-fin Porcupinefish.
Guinephol pufferfish have two different color shapes, which can occur at different stages of life, but we do not know when or why color changes occur.
One is white-stained purple-black, the other is bright yellow, often with black spots (the fish is also known as the golden pufferfish). There is also a tropical stage, where the fish may have yellow patches with black spots with white spots.
Pufferfishes have been named for their ability to stretch their stomachs, swallowing a large amount of water (or sometimes air) very quickly, causing their bodies to swell to their usual size manifold as a defense against predators.
Most species also have a spine. In most puffers, they are hidden until inflamed, while the porcupinefish has an outer spine that is always visible. Either way, when the fish are inflamed, it turns itself into an agile and overwhelming thing that no predator can easily swallow.
In addition to this ability, many species of pufferfish carry tetrodotoxin, which is the deadliest poison found in a vertebrate region. This toxin is 1200 times more deadly than cyanide.
The amount of toxin in a fish varies by species, but in some cases, one fish carries enough to kill up to 30 adult humans.
This toxin is produced by bacteria that live in the gut and eat pufferfish in certain foods A puffer grown in the aquarium will lack toxin. The toxin is found in fish liver, intestines, and ovaries and in some cases on the skin.
Keep in mind that this is a poison, not a poison, which means that the fish does not apply poison through its spine or bite but if given a cage, the fish is extremely toxic.
Although toxins do not live in the meat itself, even small amounts of contamination from the organs or skin can prove fatal. Despite this (or perhaps because of it), Pfefferfi is considered a taste in Japan, where it is known as Fugu. Properly prepared, it causes some discomfort to the lips and tongue and probably seems to have a feeling of ecstasy.
Although regulations vary across Japan, chefs have to be trained anywhere from two years to three years and undergo rigorous testing to be able to prepare and serve Fugu.
Even though there are laws regarding the making and serving of fugu, people sometimes eat and die. However, death is not the only possible outcome: Fungus can cause a variety of unpleasant symptoms, and at the right dose, it can lead to a paralytic disease that is similar to death.
In this case, the pulse of the victim and the breathing speed are reduced, the pupils become stable and dilated and the consciousness may change. This state may result in death or permanent brain damage due to hypoxia.
While in this state many old accounts of Japan have been declared dead. Stories tell of awareness throughout the human experience and heard of declaring themselves dead and crying to their relatives.
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In some cases, the account says that the person came out of the paralysis of the corpse on his way to the tomb, burial, or buried. When someone dies of poisoning in Fugu, it is customary for a family to wake up or wait a few days before cremation.
Wade Davis, an anthropological plant with a Ph.D. at Harvard, describes the process by which a person was buried alive with powder, along with pufferfish, other toxic elements, would be buried alive, then excavated and resurrected by a goat, and fed by a continuous stratum of Datura.
Food, not ‘zombie moss’ in Haiti The plant, which is known hyalusinajenika can induce the psychotic conditions. This process, with the belief in Haiti about the couple, allowed the goer to enslave and control the people for his own gain.
Although there has been much controversy among scientists over Davis’ methods and conclusions, the details of how tetrodotoxin is used in this process certainly seem to be in the field of possibility and should not be excluded.
It also seems that humans are not the only animals to use this tetrodotoxin or to enjoy its effects. Dolphins have been seen chewing slowly and getting closer to pufferfish and seem to have become addicted to it.
In this video, they are seen doing just that. Although there are no studies showing the precise effects of tetrodotoxin on dolphin brains, they seem to be enjoying themselves!
I hope, this article on are all Puffer or Fugu fish poisonous to touch and eat- was found useful to you.
Amazingly, the meat of some pufferfish is considered a delicacy. Called fugu in Japan, it is extremely expensive and only prepared by trained, licensed chefs who know that one bad cut means almost certain death for a customer. In fact, many such deaths occur annually.
There are more than 120 species of pufferfish worldwide. Most are found in tropical and subtropical ocean waters, but some species live in brackish and even fresh water. They have long, tapered bodies with bulbous heads. Some wear wild markings and colors to advertise their toxicity, while others have more muted or cryptic coloring to blend in with their environment.
They range in size from the 1-inch-long dwarf or pygmy puffer to the freshwater giant puffer, which can grow to more than 2 feet in length. They are scaleless fish and usually have rough to spiky skin. All have four teeth that are fused together into a beak-like form.
The diet of the pufferfish includes mostly invertebrates and algae. Large specimens will even crack open and eat clams, mussels, and shellfish with their hard beaks. Poisonous puffers are believed to synthesize their deadly toxin from the bacteria in the animals they eat.
Leap onto land saves fish from being eaten
Fish on the South Pacific island of Rarotonga have evolved the ability to survive out of water and leap about on the rocky shoreline because this helps them escape predators in the ocean, a ground-breaking new study shows.
"Avoiding predators might be an explanation of why some animals move from their ancestral homes into starkly different environments, but evidence for this is rare because it is difficult to collect," says study first author Dr Terry Ord of UNSW Sydney.
"Our study of blennies on Rarotonga is the first to examine the pressures driving fish out of the water. There obviously have to be some major benefits for fish to make the dramatic shift onto land. Otherwise, why would they do it?
"It turns out the aquatic environment is a nasty place for blennies, full of enemies wanting to eat these small fish. But life is less hostile on the rocks, with birds their main worry," he says.
The study, by scientists at UNSW and the Australian National University, is published in The American Naturalist.
Rarotonga in the Cook Islands provides an extraordinary opportunity to study fish evolution in action because four species of blennies have independently emerged from the water to spend various amounts of time times on land.
The researchers observed the behaviour of three of these amphibious species, which divide their time between the water, the rock shelf in the intertidal zone, and the exposed land above the high tide mark.
"At low tide most of the blennies were on the rock shelf in the intertidal zone. Those remaining in the water actively avoided areas where there were predators, such as flounders, trevallies, wrasses and moray eels," says Dr Ord.
"As the tide came in and the rock shelf became submerged, most of the blennies moved to higher ground, above the high tide mark, apparently to avoid being eaten by the aquatic predators coming in with the rising water."
The team also created 250 replica blennies out of plasticine, and placed them in the water and on land above the high tide mark.
"There were far more attacks on the model fish from predators in the ocean than predators on the shore, showing there are obvious benefits for blennies in becoming fish out of water and colonising the land," says Dr Ord.
Other reasons fish might move onto land could be to find new sources of food, to escape competition for resources, or to escape adverse fluctuations in water conditions.
Predator fish pose a bigger threat to young coral than we thought
You are free to share this article under the Attribution 4.0 International license.
Young corals are more vulnerable to predators like pufferfish and parrotfish than previously believed, a new study shows.
The finding holds true whether a coral colony finds itself alone on the reef or surrounded by others of its kind.
You might not think an animal made out of stone would have much to worry about in the way of predators, and that’s largely what scientists had thought about coral.
“I think it just turns out that this coral is so tasty that predators simply mowed everything down.”
Although corallivores like parrotfish and pufferfish are well known to biologists, their impact on coral growth and survival was believed to be small compared to factors like heatwaves, ocean acidification, and competition from algae.
In their new work, researchers wanted to examine how corals can reemerge following large disturbances like cyclones and marine heatwaves, which periodically devastate the reefs of Mo’orea, French Polynesia, where they conducted their study.
“Mo’orea is prone to big heat shocks, storm waves, cyclones, and predatory sea star outbreaks,” says coauthor Adrian Stier, an associate professor in the ecology evolution and marine biology department at the University of California, Santa Barbara, and an advisor for Kai Kopecky a doctoral student and lead author of the paper in the journal Coral Reefs.
“It just wipes the slate clean in terms of coral death. And sometimes, just a few years later, you can swim around and see thriving life,” says Stier. “We’re still really curious about what allows these ecosystems to bounce back.”
Coral predators shape colonies
Scientists had implicated predators in shaping coral population dynamics, but there hadn’t really been many direct studies.
“People who study coral reefs have thought a lot about the supply of new babies coming from elsewhere, or limitation by the amount of nutrients, or competition with algae as important drivers of coral recovery,” Stier says. “But there hasn’t been as much done on the importance of predators as a limiting factor.”
After reviewing the literature on coral growth, mortality, and predation, Kopecky decided to focus on the effects predation and density had on young coral colonies.
He planted small nubbins of Pacific staghorn coral at various locations on the reef either alone, in a group of four, or in a group of eight. Metal cages protected some of these groups, while others were left exposed. For the unprotected coral, Kopecky sought to determine whether high density increased or decreased predation on the staghorn. For the protected groups, he was curious how density influenced coral growth.
The researchers found that protection was key to these small corals’ futures. After 30 days out on the reef, nearly all of the unprotected nubbins had been completely consumed. In fact, density had virtually no effect on this outcome.
‘Popcorn chicken’ of the reef
The researchers let the experiment run for an entire year. When they returned, virtually none of the unprotected specimens remained. On the other hand, the caged corals had outgrown their accommodations by year’s end.
“The corals that were protected grew all the way into the upper corners of the cages and were poking little branches out,” Kopecky recalls. “They formed a cube of coral inside the cages, whereas the ones that were exposed to predators were just barely hanging on.”
Coral are not typically fast-growing organisms, but staghorn coral grows quickly, giving it a competitive edge following disturbances that remove large amounts of coral. According to Kai, however, staghorn coral are like the popcorn chicken of the reef: irresistible to a hungry corallivore.
The protected corals grew so quickly that Kai had to adopt a different way to measure them, because at a certain point the nubbins fused, and he could no longer unscrew their base plates to measure them in the lab.
So, if there’s no protection in numbers for these tasty staghorns, how do they ever survive their infancy?
The corals benefit from the protection of fish like the Dusky farmerfish, which farms algae on the reef. These farmer fish doggedly defend their territories, offering protection to any small coral that happens to settle in their range, Kopecky says.
And while algae and coral are often considered archenemies—with the former able to outcompete the later—by munching on their crops, the farmer fish keep the algae in check. This enables the coral to get through the stage where they’re vulnerable to predation.
In fact, researchers rarely see staghorn corals in large colonies absent the protection of these fishy farmers, Kopecky says.
The authors thought density would have some effect on predation. “I think it just turns out that this coral is so tasty that predators simply mowed everything down,” Stier says.
The team is considering running a similar experiment with cauliflower coral, which is more robust and slower-growing than the staghorn. Hopefully it’s also slightly less scrumptious, as well.
“When these pufferfish eat enough, you can see their bellies weighted down by the coral rocks that are in their stomachs,” Stier says. “I mean, they’re oddly shaped fish to begin with they’re already having a hard time swimming without that ballast, but this makes it extra tricky.”
“It really is a cartoonish dynamic,” Kopecky says.
Staghorn coral is widely used in reef restoration efforts, especially in the Caribbean where this and a related species (elkhorn coral) are endangered. In fact, before joining UC Santa Barbara, Kopecky spent several months working as a coral restoration technician on the US Virgin Islands.
“I had an opportunity to see coral restoration in action, but also see some of the limitations associated with it,” Kopecky says. “And then I was able to go and conduct research, like this experiment, that can feed back into and inform how restoration might be improved.”
Getting outplanted coral nubbins through this vulnerable life stage presents a major bottleneck to restoration efforts, Kopecky says. He has already received feedback on the study from people engaged in coral reef restoration expressing how relevant his findings are to their work.
“When you protect these young, vulnerable corals from predators, the amount of growth is substantially higher than when they’re not protected,” Kopecky says. “It’s clear that coral predators can really shape whether young corals actually reach the size where they’re no longer vulnerable to predation.”
Staying out of sight Edit
Animals may avoid becoming prey by living out of sight of predators, whether in caves, burrows, or by being nocturnal.     Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. This is a behavioral form of detection avoidance called crypsis used by animals to either avoid predation or to enhance prey hunting. Predation risk has long been recognized as critical in shaping behavioral decisions. For example, this predation risk is of prime importance in determining the time of evening emergence in echolocating bats. Although early access during brighter times permits easier foraging, it also leads to a higher predation risk from bat hawks and bat falcons. This results in an optimum evening emergence time that is a compromise between the conflicting demands. 
Another nocturnal adaptation can be seen in kangaroo rats. They forage in relatively open habitats, and reduce their activity outside their nest burrows in response to moonlight. During a full moon, they shift their activity towards areas of relatively dense cover to compensate for the extra brightness. 
Camouflage uses any combination of materials, coloration, or illumination for concealment to make the organism hard to detect by sight. It is common in both terrestrial and marine animals. Camouflage can be achieved in many different ways, such as through resemblance to surroundings, disruptive coloration, shadow elimination by countershading or counter-illumination, self-decoration, cryptic behavior, or changeable skin patterns and colour.   Animals such as the flat-tail horned lizard of North America have evolved to eliminate their shadow and blend in with the ground. The bodies of these lizards are flattened, and their sides thin towards the edge. This body form, along with the white scales fringed along their sides, allows the lizards to effectively hide their shadows. In addition, these lizards hide any remaining shadows by pressing their bodies to the ground. 
Animals can hide in plain sight by masquerading as inedible objects. For example, the potoo, a South American bird, habitually perches on a tree, convincingly resembling a broken stump of a branch,  while a butterfly, Kallima, looks just like a dead leaf. 
Apostatic selection Edit
Another way to remain unattacked in plain sight is to look different from other members of the same species. Predators such as tits selectively hunt for abundant types of insect, ignoring less common types that were present, forming search images of the desired prey. This creates a mechanism for negative frequency-dependent selection, apostatic selection. 
Many species make use of behavioral strategies to deter predators. 
Startling the predator Edit
Many weakly-defended animals, including moths, butterflies, mantises, phasmids, and cephalopods such as octopuses, make use of patterns of threatening or startling behaviour, such as suddenly displaying conspicuous eyespots, so as to scare off or momentarily distract a predator, thus giving the prey animal an opportunity to escape. In the absence of toxins or other defences, this is essentially bluffing, in contrast to aposematism which involves honest signals.   
Pursuit-deterrent signals Edit
Pursuit-deterrent signals are behavioral signals used by prey that convince predators not to pursue them. For example, gazelles stot, jumping high with stiff legs and an arched back. This is thought to signal to predators that they have a high level of fitness and can outrun the predator. As a result, predators may choose to pursue a different prey that is less likely to outrun them.  White-tailed deer and other prey mammals flag with conspicuous (often black and white) tail markings when alarmed, informing the predator that it has been detected.  Warning calls given by birds such as the Eurasian jay are similarly honest signals, benefiting both predator and prey: the predator is informed that it has been detected and might as well save time and energy by giving up the chase, while the prey is protected from attack.  
Playing dead Edit
Another pursuit-deterrent signal is thanatosis or playing dead. Thanatosis is a form of bluff in which an animal mimics its own dead body, feigning death to avoid being attacked by predators seeking live prey. Thanatosis can also be used by the predator in order to lure prey into approaching.  An example of this is seen in white-tailed deer fawns, which experience a drop in heart rate in response to approaching predators. This response, referred to as "alarm bradycardia", causes the fawn's heart rate to drop from 155 to 38 beats per minute within one beat of the heart. This drop in heart rate can last up to two minutes, causing the fawn to experience a depressed breathing rate and decrease in movement, called tonic immobility. Tonic immobility is a reflex response that causes the fawn to enter a low body position that simulates the position of a dead corpse. Upon discovery of the fawn, the predator loses interest in the "dead" prey. Other symptoms of alarm bradycardia, such as salivation, urination, and defecation, can also cause the predator to lose interest. 
Marine molluscs such as sea hares, cuttlefish, squid and octopuses give themselves a last chance to escape by distracting their attackers. To do this, they eject a mixture of chemicals, which may mimic food or otherwise confuse predators.   In response to a predator, animals in these groups release ink, creating a cloud, and opaline, affecting the predator's feeding senses, causing it to attack the cloud.  
Distraction displays attract the attention of predators away from an object, typically the nest or young, that is being protected.  Distraction displays are performed by some species of birds, which may feign a broken wing while hopping about on the ground, and by some species of fish. 
Mimicry and aposematism Edit
Mimicry occurs when an organism (the mimic) simulates signal properties of another organism (the model) to confuse a third organism. This results in the mimic gaining protection, food, and mating advantages.  There are two classical types of defensive mimicry: Batesian and Müllerian. Both involve aposematic coloration, or warning signals, to avoid being attacked by a predator.  
In Batesian mimicry, a palatable, harmless prey species mimics the appearance of another species that is noxious to predators, thus reducing the mimic's risk of attack.  This form of mimicry is seen in many insects. The idea behind Batesian mimicry is that predators that have tried to eat the unpalatable species learn to associate its colors and markings with an unpleasant taste. This results in the predator learning to avoid species displaying similar colours and markings, including Batesian mimics, which are in effect parasitic on the chemical or other defences of the unprofitable models.   Some species of octopus can mimic a selection of other animals by changing their skin color, skin pattern and body motion. When a damselfish attacks an octopus, the octopus mimics a banded sea-snake.  The model chosen varies with the octopus's predator and habitat.  Most of these octopuses use Batesian mimicry, selecting an organism repulsive to predators as a model.  
In Müllerian mimicry, two or more aposematic forms share the same warning signals,   as in viceroy and monarch butterflies. Birds avoid eating both species because their wing patterns honestly signal their unpleasant taste. 
Defensive structures Edit
Many animals are protected against predators with armour in the form of hard shells (such as most molluscs), leathery or scaly skin (as in reptiles), or tough chitinous exoskeletons (as in arthropods). 
A spine is a sharp, needle-like structure used to inflict pain on predators. An example of this seen in nature is in the Sohal surgeonfish. These fish have a sharp scalpel-like spine on the front of each of their tail fins, able to inflict deep wounds. The area around the spines is often brightly colored to advertise the defensive capability  predators often avoid the Sohal surgeonfish.  Defensive spines may be detachable, barbed or poisonous. Porcupine spines are long, stiff, break at the tip, and are barbed to stick into a would-be predator. In contrast, the hedgehog's short spines, which are modified hairs,  readily bend, and are barbed into the body, so they are not easily lost they may be jabbed at an attacker. 
Many species of slug caterpillar, Limacodidae, have numerous protuberances and stinging spines along their dorsal surfaces. Species that possess these stinging spines suffer less predation than larvae that lack them, and a predator, the paper wasp, chooses larvae without spines when given a choice. 
Group living can decrease the risk of predation to the individual in a variety of ways,  as described below.
Dilution effect Edit
A dilution effect is seen when animals living in a group "dilute" their risk of attack, each individual being just one of many in the group. George C. Williams and W.D. Hamilton proposed that group living evolved because it provides benefits to the individual rather than to the group as a whole, which becomes more conspicuous as it becomes larger. One common example is the shoaling of fish. Experiments provide direct evidence for the decrease in individual attack rate seen with group living, for example in Camargue horses in Southern France. The horse-fly often attacks these horses, sucking blood and carrying diseases. When the flies are most numerous, the horses gather in large groups, and individuals are indeed attacked less frequently.  Water striders are insects that live on the surface of fresh water, and are attacked from beneath by predatory fish. Experiments varying the group size of the water striders showed that the attack rate per individual water strider decreases as group size increases. 
Selfish herd Edit
The selfish herd theory was proposed by W.D. Hamilton to explain why animals seek central positions in a group.  The theory's central idea is to reduce the individual's domain of danger. A domain of danger is the area within the group in which the individual is more likely to be attacked by a predator. The center of the group has the lowest domain of danger, so animals are predicted to strive constantly to gain this position. Testing Hamilton's selfish herd effect, Alta De Vos and Justin O'Rainn (2010) studied brown fur seal predation from great white sharks. Using decoy seals, the researchers varied the distance between the decoys to produce different domains of danger. The seals with a greater domain of danger had an increased risk of shark attack. 
Predator satiation Edit
A radical strategy for avoiding predators which may otherwise kill a large majority of the emerging stage of a population is to emerge very rarely, at irregular intervals. Predators with a life-cycle of one or a few years are unable to reproduce rapidly enough in response to such an emergence. Predators may feast on the emerging population, but are unable to consume more than a fraction of the brief surfeit of prey. Periodical cicadas, which emerge at intervals of 13 or 17 years, are often used as an example of this predator satiation, though other explanations of their unusual life-cycle have been proposed. 
Alarm calls Edit
Animals that live in groups often give alarm calls that give warning of an attack. For example, vervet monkeys give different calls depending on the nature of the attack: for an eagle, a disyllabic cough for a leopard or other cat, a loud bark for a python or other snake, a "chutter". The monkeys hearing these calls respond defensively, but differently in each case: to the eagle call, they look up and run into cover to the leopard call, they run up into the trees to the snake call, they stand on two legs and look around for snakes, and on seeing the snake, they sometimes mob it. Similar calls are found in other species of monkey, while birds also give different calls that elicit different responses. 
Improved vigilance Edit
In the improved vigilance effect, groups are able to detect predators sooner than solitary individuals.  For many predators, success depends on surprise. If the prey is alerted early in an attack, they have an improved chance of escape. For example, wood pigeon flocks are preyed upon by goshawks. Goshawks are less successful when attacking larger flocks of wood pigeons than they are when attacking smaller flocks. This is because the larger the flock size, the more likely it is that one bird will notice the hawk sooner and fly away. Once one pigeon flies off in alarm, the rest of the pigeons follow.  Wild ostriches in Tsavo National Park in Kenya feed either alone or in groups of up to four birds. They are subject to predation by lions. As the ostrich group size increases, the frequency at which each individual raises its head to look for predators decreases. Because ostriches are able to run at speeds that exceed those of lions for great distances, lions try to attack an ostrich when its head is down. By grouping, the ostriches present the lions with greater difficulty in determining how long the ostriches' heads stay down. Thus, although individual vigilance decreases, the overall vigilance of the group increases. 
Predator confusion Edit
Individuals living in large groups may be safer from attack because the predator may be confused by the large group size. As the group moves, the predator has greater difficulty targeting an individual prey animal. The zebra has been suggested by the zoologist Martin Stevens and his colleagues as an example of this. When stationary, a single zebra stands out because of its large size. To reduce the risk of attack, zebras often travel in herds. The striped patterns of all the zebras in the herd may confuse the predator, making it harder for the predator to focus in on an individual zebra. Furthermore, when moving rapidly, the zebra stripes create a confusing, flickering motion dazzle effect in the eye of the predator. 
Defensive structures such as spines may be used both to ward off attack as already mentioned, and if need be to fight back against a predator.  Methods of fighting back include chemical defences,  mobbing,  defensive regurgitation,  and suicidal altruism. 
Chemical defences Edit
Many prey animals, and to defend against seed predation also seeds of plants,  make use of poisonous chemicals for self-defence.   These may be concentrated in surface structures such as spines or glands, giving an attacker a taste of the chemicals before it actually bites or swallows the prey animal: many toxins are bitter-tasting.  A last-ditch defence is for the animal's flesh itself to be toxic, as in the puffer fish, danaid butterflies and burnet moths. Many insects acquire toxins from their food plants Danaus caterpillars accumulate toxic cardenolides from milkweeds (Asclepiadaceae). 
Some prey animals are able to eject noxious materials to deter predators actively. The bombardier beetle has specialized glands on the tip of its abdomen that allows it to direct a toxic spray towards predators. The spray is generated explosively through oxidation of hydroquinones and is sprayed at a temperature of 100 °C.  Armoured crickets similarly release blood at their joints when threatened (autohaemorrhaging).  Several species of grasshopper including Poecilocerus pictus,  Parasanaa donovani,  Aularches miliaris,  and Tegra novaehollandiae secrete noxious liquids when threatened, sometimes ejecting these forcefully.  Spitting cobras accurately squirt venom from their fangs at the eyes of potential predators,  striking their target eight times out of ten, and causing severe pain.  Termite soldiers in the Nasutitermitinae have a fontanellar gun, a gland on the front of their head which can secrete and shoot an accurate jet of resinous terpenes "many centimeters". The material is sticky and toxic to other insects. One of the terpenes in the secretion, pinene, functions as an alarm pheromone.  Seeds deter predation with combinations of toxic non-protein amino acids, cyanogenic glycosides, protease and amylase inhibitors, and phytohemaglutinins. 
A few vertebrate species such as the Texas horned lizard are able to shoot squirts of blood from their eyes, by rapidly increasing the blood pressure within the eye sockets, if threatened. Because an individual may lose up to 53% of blood in a single squirt,  this is only used against persistent predators like foxes, wolves and coyotes (Canidae), as a last defence.  Canids often drop horned lizards after being squirted, and attempt to wipe or shake the blood out of their mouths, suggesting that the fluid has a foul taste  they choose other lizards if given the choice,  suggesting a learned aversion towards horned lizards as prey. 
The slime glands along the body of the hagfish secrete enormous amounts of mucus when it is provoked or stressed. The gelatinous slime has dramatic effects on the flow and viscosity of water, rapidly clogging the gills of any fish that attempt to capture hagfish predators typically release the hagfish within seconds (pictured above). Common predators of hagfish include seabirds, pinnipeds and cetaceans, but few fish, suggesting that predatory fish avoid hagfish as prey. 
Communal defence Edit
In communal defence, prey groups actively defend themselves by grouping together, and sometimes by attacking or mobbing a predator, rather than allowing themselves to be passive victims of predation. Mobbing is the harassing of a predator by many prey animals. Mobbing is usually done to protect the young in social colonies. For example, red colobus monkeys exhibit mobbing when threatened by chimpanzees, a common predator. The male red colobus monkeys group together and place themselves between predators and the group's females and juveniles. The males jump together and actively bite the chimpanzees.  Fieldfares are birds which may nest either solitarily or in colonies. Within colonies, fieldfares mob and defecate on approaching predators, shown experimentally to reduce predation levels. 
Defensive regurgitation Edit
Some birds and insects use defensive regurgitation to ward off predators. The northern fulmar vomits a bright orange, oily substance called stomach oil when threatened.  The stomach oil is made from their aquatic diets. It causes the predator's feathers to mat, leading to the loss of flying ability and the loss of water repellency.  This is especially dangerous for aquatic birds because their water repellent feathers protect them from hypothermia when diving for food. 
European roller chicks vomit a bright orange, foul smelling liquid when they sense danger. This repels prospective predators and may alert their parents to danger: they respond by delaying their return. 
Numerous insects utilize defensive regurgitation. The eastern tent caterpillar regurgitates a droplet of digestive fluid to repel attacking ants.  Similarly, larvae of the noctuid moth regurgitate when disturbed by ants. The vomit of noctuid moths has repellent and irritant properties that help to deter predator attacks. 
Suicidal altruism Edit
An unusual type of predator deterrence is observed in the Malaysian exploding ant. Social hymenoptera rely on altruism to protect the entire colony, so the self-destructive acts benefit all individuals in the colony.  When a worker ant's leg is grasped, it suicidally expels the contents of its hypertrophied submandibular glands,  expelling corrosive irritant compounds and adhesives onto the predator. These prevent predation and serve as a signal to other enemy ants to stop predation of the rest of the colony. 
The normal reaction of a prey animal to an attacking predator is to flee by any available means, whether flying, gliding,  falling, swimming, running, jumping, burrowing  or rolling,  according to the animal's capabilities.  Escape paths are often erratic, making it difficult for the predator to predict which way the prey will go next: for example, birds such as snipe, ptarmigan and black-headed gulls evade fast raptors such as peregrine falcons with zigzagging or jinking flight.  In the tropical rain forests of Southeast Asia in particular, many vertebrates escape predators by falling and gliding.  Among the insects, many moths turn sharply, fall, or perform a powered dive in response to the sonar clicks of bats.  Among fish, the stickleback follows a zigzagging path, often doubling back erratically, when chased by a fish-eating merganser duck. 
Some animals are capable of autotomy (self-amputation), shedding one of their own appendages in a last-ditch attempt to elude a predator's grasp or to distract the predator and thereby allow escape. The lost body part may be regenerated later. Certain sea slugs discard stinging papillae arthropods such as crabs can sacrifice a claw, which can be regrown over several successive moults among vertebrates, many geckos and other lizards shed their tails when attacked: the tail goes on writhing for a while, distracting the predator, and giving the lizard time to escape a smaller tail slowly regrows. 
Aristotle recorded observations (around 350 BC) of the antipredator behaviour of cephalopods in his History of Animals, including the use of ink as a distraction, camouflage, and signalling. 
In 1940, Hugh Cott wrote a compendious study of camouflage, mimicry, and aposematism, Adaptive Coloration in Animals. 
By the 21st century, adaptation to life in cities had markedly reduced the antipredator responses of animals such as rats and pigeons similar changes are observed in captive and domesticated animals. 
The puffer fish, also called blowfish, swellfish, globefish, balloonfish, bubblefish are fish making up the family Tetraodontidae, within the order Tetraodontiformes.
They are named for their ability to inflate themselves to several times their normal size by swallowing water or air when threatened the same adaptation is found in the closely related porcupinefish, which have large conspicuous spines (unlike the small, almost sandpaper-like spines of puffer fish).
The scientific name, Tetraodon, refers to the fact that they have four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and mollusks, their natural prey.
The eyes and internal organs of most puffer fish are highly toxic, but nevertheless the meat is considered a delicacy in Japan and Korea.
Tetrodotoxin, a chemical present in the pufferfish, is a powerful neurotoxin that can cause death in nearly 60% of the humans that ingest it.
A human only has to ingest a few milligrams for a fatal reaction to the toxin to occur.
How bacterial predators evolved to kill other bacteria without harming themselves
A joint study by the labs of Dr Andrew Lovering and Prof Liz Sockett, at the Universities of Birmingham and Nottingham, has shown how predatory bacteria protect themselves from the weapons they use in their bacterial killing pathway.
The research, published in Nature Communications, offers insights into early steps in the evolution of bacterial predators and will help to inform new ways of combatting antimicrobial resistance.
A useful predatory bacterium called Bdellovibrio bacteriovorus eats other bacteria (including important pathogens of humans, animals and crops).
It attacks them from inside out using enzymes (called DD-endopeptidases) that first loosen the cell walls of prey bacteria and then cause them to round up like a pufferfish, providing space as a temporary home for the predator.
However, Bdellovibrio also have similar cell walls so why don't they fall victim of their own attack?
The project, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), found that the bacterium uses an ankyrin-type protein called Bd3460 as a shield. It binds to the tip of the enzyme weapons, nullifying their action until they are safely secreted out of the Bdellovibrio and into the prey bacteria.
Dr. Andrew Lovering and Ian Cadby at the University of Birmingham determined the structure of the ankyrin protein using X-ray crystallography and found that that it attaches to two DD-endopeptidase weapons to temporarily deactivate them.
"When I first showed this to Liz, she hit the nail on the head by describing it as a decorative "quiff" on top of the endopeptidase" said Dr Lovering. "This covers up the active site of the enzymes that are used to cut cell walls and offers protection to the Bdellovibrio until these weapons are excreted into the prey."
Carey Lambert, Rob Till and Prof Liz Sockett at The University of Nottingham confirmed the antidote protein's use when the gene responsible for its production was deleted.
Prof Liz Sockett said: "When the Bd3460 gene responsible for antidote production was deleted, the Bdellovibrio had no way of protecting itself from its own weapons. When it attacked harmful bacteria with its cell-wall-damaging enzymes it also felt the effects.
"The Bdellovibrio bacteria lacking the Bd3460 gene tried to invade the bacteria but suddenly rounded up like pufferfish and couldn't complete the invasion -- the fatter predator cell could not enter the prey cell."
This is the first paper to discover a 'self-protection' protein in predatory bacteria.
Prof Liz Sockett added, "Most bacteria are not predatory and so understanding these mechanisms gives us a glimpse of how predation evolved. In this case it seems that the Bd3460 gene was transferred into ancestors of Bdellovibrio, probably when they were beginning to develop as predators."
Commenting on the potential impact of the study, Dr Andrew Lovering added: "If we are to use Bdellovibrio as a therapeutic in the future, we need to understand the mechanisms underpinning prey killing and be sure that any self-protective genes couldn't be acquired by pathogens, causing resistance. Brilliantly, Liz and Carey have demonstrated this did not happen with the bd3460 antidote protein, and Ian and I showed how the mechanism works on predator enzymes only -- this is a great inter-university collaboration."
What's inside a puffer fish
Narrator: If there's one thing you know about puffer fish, it's that they can do this. When aggravated by a predator, they, you know, puff up. Some puffers, like the porcupine fish, become a bona fide spike ball, moving through the water seemingly out of control.
But if you peer inside a puffer, you'll learn that puffing up isn't the only trait that makes these fish one of the most threatening creatures in the sea.
Contrary to what it looks like, puffer fish are not like balloons. Because what's normally inside them isn't air. It's water.
Elizabeth Brainerd: What they do is they actually take water into their mouths in a big mouthful of water, and then they pump it down into their stomach.
Narrator: That's Elizabeth Brainerd, a biologist and puffer fish expert at Brown University.
Brainerd: And they do that anywhere 10 or 15 times, pump, pump, pump, pump, pump, pump, until they inflate completely, and then they hold it and they'll just be a big, spiny ball.
Narrator: And as you might expect, this requires some pretty sophisticated biology, starting with the stomach. It's made of dozens of tiny folds, kind of like an accordion. These folds are important because when the stomach fills up with water, it can expand without rupturing. And puffer fish expand a lot. Up to three times their size. That's like if an average human man could inflate his waist to a circumference of 3 meters.
But there is a drawback to these amazing skills. Brainerd suspects that puffer fish stomachs have actually lost the ability to digest food, which means their intestines have to do all the work.
Brainerd: You know, given the apparent importance of this defense mechanism, they've given up the advantages of having a stomach where some digestion can start.
Narrator: But the stomach? It's just one of many bizarre features inside a puffer. For example, they have specialized muscles that you won't find in most other fish. Some in their mouth, which pump all that water into their stomach some in their esophagus, to seal off their stomach like a drain plug once it's full and some in the base of their bellies, which contract to squeeze out water when they're ready to deflate. But what you won't find inside is even more bizarre.
Brainerd: There are a couple characters that are really helpful in their ability to puff up, and one of those is that they don't have any ribs, and another one is they don't have any pelvis.
Narrator: In other words, puffers are essentially missing bones. And that's a good thing, because otherwise they'd get in the way of inflation. In fact, according to Brainerd, if it weren't for these missing bones, puffer fish would probably have never evolved this way in the first place. And that would be a shame, since puffing up really is a good defense.
Consider one old study in which researchers watched birds go fishing. The birds caught 11 puffer fish, but they dropped nearly half of them because the fish started to inflate. But what's more surprising is that the birds left with empty beaks might have been the lucky ones.
Because puffers have another, more potent defense up their sleeves. Their bodies are laced with a neurotoxin called tetrodotoxin. It's up to 1,200 times more poisonous than cyanide. So poisonous that one puffer fish can kill 30 adult humans. So poisonous that puffers are reportedly the second most poisonous vertebrate in the world, which is why it's also surprising that us humans? We actually eat them. That's right. In Japan, puffer fish is actually a delicacy called fugu, which only trained chefs can prepare.
And considering that these fish are basically spike balls filled with poison and we're still serving them in restaurants, they must be seriously delicious.