Why do we say that fish is brain food? If this were true, why wouldn't the fish  smart enough to avoid capture
356703
It's not the fish that are smart, their brains are relatively small, but the Omega 3 fatty acids and the iodine that their flesh is rich in are the substances that human brains can use to function better. Fish live in an environment where, to survive, they have to eat other fish and they themselves run the risk of being eaten 24 hours a day. This is why they swim in shoals so that larger, predator, fish will avoid them as the shape they see gives them the impression that the shoal itself, is a big fish waiting to eat them.
349380
We don't know that humans are the only creatures that can think deeper.  There's evidence that whales are quite intelligent.  Not to mention there's an awful lot of universe out there to contimplate.
434011
Fish eats seaweads and some fish eats fish.  What kind of proof u need just dive and u will see the proof
1171485
This is all a question of perspective. Many organisms are predator and prey at the same time. A bass eats a minnow and is thus a predator, but the bass is eaten by an osprey or a human and is thus also prey. There are only a few organisms at the very bottom of the food chain (like plants) that are almost exclusively prey, and a very few organisms at the top of the food chain (like humans, lions, and osprey) that are primarily predators and rarely prey.\n\nBiochemically, most organisms are actually very similar, with the exception of those organisms that are only prey and have specializations for making their own food from inorganic sources (for example, photosynthesis and chemosynthesis). When life first formed, all organisms that existed could make all the nutrients they needed by some sort of autotrophy (photosynthesis is an example of autotrophy). However, some organisms found that they could do better by taking the molecules that other organisms produced (by eating them) rather than making their own. Thus, the first predators were created.\n\nOrganisms that used this strategy accumulated many specializations that made them better predators. Mobility, vision, and teeth are all adaptations that help a predator take organic molecules produced by others. Many sorts of behaviors also make a better predator—stalking behavior is a good example. The neuronal circuitry in the nervous systems of predators enables the behaviors. These adaptations took hundreds of millions of years to evolve.\n\nThe first predators, the ones living in the soup that spawned life, probably did nothing more complex than bump into their prey (they were only single celled and did not have anything like a multicellular brain). In the time since then, though, as organisms achieved multicellularity and increased complexity, they have become increasingly sophisticated in the behaviors they use to gather food from prey.
1065310
Sensory and nervous system\nFishes have well-developed nervous systems that organize around a central brain, that is divided into different parts. The most anterior, or front, end of the brain are the olfactory bulbs, which are involved in the fish's sense of smell. Unlike most vertebrates, the cerebrum of the fish primarily processes the sense of smell rather than being responsible for all voluntary actions. The optic lobes process information from the eyes. The cerebellum coordinates body movements while the medulla oblongata controls the functions of internal organs. Most fishes possess highly developed sense organs. Nearly all daylight fish have well-developed eyes that have color vision that is at least good as a human's. Many fish also have specialized cells known as chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears in their heads, many fish may not hear sounds very well. However, most fishes have sensitive receptors that form the lateral line system. The lateral line system allows for many fish to detect gentle currents and vibrations, as well as to sense the motion of other nearby fish and prey. Some fishes, such as catfish and sharks, have organs that detect low levels electric current. Other fishes, like the electric eel, can produce their own electricity.
145200
right.. Reasoning superseeds thinking.  Reasoning is a higher cognative brain function.  Dogs and cats can think, but not quite reason.  If a dog is hungry and has access to food, they will eat it. It's not really a choice for them.  A hungry person can save the food for later and be totally comfortable not eating because they understand... through reasoning, they are not going to starve, they can eat in awhile and everything will be just fine.\n\nA hungry dog's thought process is pretty much stuck on.... food food i need food im hungry must eat food gemme food.\n\nknow what i mean?  jellybean
390242
Everything that lives on or in land or water or the sky is intelligent enough to have survived till now against a plethora of predators. The future will let us know if man is intelligent enough to survive the most dangerous predator of them all - MAN Himself!
462727
Porpoises (I assume you mean small cetaceans) hunt their food with natural sonar (like bats), and it's sensitive enough for them to distinguish between healthy fish and sick fish (or, presumably, dead fish). So they're not likely to go for a baited hook.\n\nBut the question is, why would you want to catch them?
866553
Worms don't really have much in the way of a brain or nervous system, so I doubt they mind.  As far as other animals, I used to be against it but I've become rather desensitized to it... Many more animals are killed to become food or fur, or killed for sport... I have to deal with killing mice on a regular basis to feed snakes... They are low on the food chain for a reason.  A few humanely euthanized rats here and there for students to learn is a small price to pay.  As a bio student, there really is no replacement for learning first hand on the real thing.  My favorite dissection was a fetal pig in high school... Very interesting.  The only time I took offense was a mink dissection, and that is because the school was actually getting the minks from fur farms and paying for them, so our experiments were fueling the fur trade...
595821
smart fish, stupid person.  he obviously is doing something that prevents you from catching him.
517409
Fishes have well-developed nervous systems that organize around a central brain, that is divided into different parts. The most anterior, or front, end of the brain are the olfactory bulbs, which are involved in the fish's sense of smell. Unlike most vertebrates, the cerebrum of the fish is primarily processes the sense of smell rather than being responsible for all voluntary actions. The optic lobes process information from the eyes. The cerebellum coordinates body movements while the medulla oblongata controls the functions of internal organs. Most fishes possess highly developed sense organs. Nearly all daylight fish have well-developed eyes that have color vision that is at least good as a human's. Many fish also have specialized cells known as chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears in their heads, many fish may not hear sounds very well. However, most fishes have sensitive receptors that form the lateral line system. The lateral line system allows for many fish to detect gentle currents and vibrations, as well as to sense the motion of other nearby fish and prey. Some fishes, such as catfish and sharks, have organs that detect low levels electric current. Other fishes, like the electric eel, can produce their own electricity.
290587
Goldfish do rest. Sleeping is a concept that is different for the various species of life in our world. Many species do not require the type of sleep that humans require. Fish do REST but, if you are wondering if they run into a cave and float aimlessly while they sleep? No, fish do not sleep. They will slow down their metabolism and REST in a safe corner of their world. Also, fish activity becomes slower in the evening and when water temperatures drop when they are in safe places.\n\nAND:\n\nMost all fish spend time in an energy-saving state that can be called "rest", and we might even call their behavior "sleep", though it is probably \n\ndifferent than "sleep" in most land animals. Many fish, like Bass and perch, rest on or under logs at night. Coral reef fish active in the day, hide and rest \n\nin crevices and cracks in the reef to avoid being eaten at night. The resting behavior of fish is very different from their behavior the rest of the day. Many \n\nminnows, for example, which are very active in schools during the day, scatter and remain motionless in shallow water at night. Many fish "rest" or \n\n"sleep" during the day and are active at night instead, but almost all fish sleep. There are some animals that never stop swimming, like many species of\n\n\nshark, however, they HAVE to keep moving to push water through their mouths in order to breathe, and they may still sleep while moving,\n\n\nwe just don't know yet.
421757
Pain is a fairly universal defense mechanism of life forms. It is nothing but the message (along neural cells) to the rest of the body (or at least the closest node in the nervous system) that something is wrong, so that the body can react by sending repair and defence agents. \n\nFish are vertebrates, and all vertebrates have a brain which coordinates most of their bodily functions. Mammals aren't that different from fish in this regard. Fish have more different sensory organs than mammals, all of which are coordinated in the brain.\n\nThere are also autonomous neural systems in vertebrate bodies. The intestines are a complex, self-regulating neural system with only little communication with the brain.\n\nIt is perfectly possible to make a fish "drunk" (i.e. reduce coordination of neural activity) by exposing it to chemicals. What levels of alcohol are required for it to act as a neurotoxic substance may differ from air-breathers, since the respiratory organs may be a better conductor for alcohol into the blood than the intestinal organs. Or in other words, think of inhalable alcohol.
1114474
Here's something to think about.\n\n"A herd of buffalo can only move as fast as the slowest buffalo. And when the herd is hunted, it is the slowest and weakest ones at the back that are killed first. This natural selection is good for the herd as a whole, because the general speed and health of the whole group keeps improving by the regular killing of the weakest members."\n\n"In much the same way, the human brain can only operate as fast as the slowest brain cells. Excessive intake of alcohol, as we know, kills brain cells. But naturally it attacks the slowest and weakest brain cells first."\n\n"In this way, regular consumption of beer eliminates the weaker brain cells, making the brain a faster and more efficient machine. That's why you always feel smarter after a few beers."
117408
Jelly fish don't have brains either yet they are capable of actions that to a human observer seem to be caused by thinking. Likewise cells act and do not have a brain. The DNA inside it contains instructions for what to do. Also insects only have a ganglia, no real brain, which just handles motor skills only, not thought. So how do they do it? In actuality they are not thinking and then doing, just doing based on instinct. An observer may notice a small pause in the actions of say a jellyfish that to a human supposes thinking about what to do. Not so. The external stimuli isn't correct yet for the action to be taken is all, and when it is correct, it acts. Clams also have no brains. Nor a Venus fly-trap yet when a fly lands there it closes the trap. It's simply cause and effect.
809981
I was thinking this question only yesterday! How strange! I'd like to know the answer to this one too. I thought Tuna were smaller than Dolphins, so they can't escape through holes in the net.
1080986
I can't say with any degree of certainty that fish are completely unphased by this experience, but for the most part the holes you make in their mouths by practicising "catch & release" will heal.  They will not affect the fishes ability to eat.  Whether a fish gets over the stress is hard to say!\n\nJust be sure to hold any fish you re-release under the water for a bit, moving it back & forth to get water running over its gills again. \n\nFish have very rudimentary nervous systems, so do not really experience "pain" the way a chicken or a gerbil might.