However, yes, they can hear your voice.
They can associate sounds with action, though. For example, if you are to say your betta fish's name – let us call him George – each time you sprinkle food in his aquarium, he will eventually associate the sound of “George” with food.
But can fish hear? Fish don't have ears that we can see, but they do have ear parts inside their heads. They pick up sounds in the water through their bodies and in their internal ear, according to the National Wildlife Federation.
Fish can develop an association between something they like, being fed, with the person who feeds them. The more you interact with your betta fish, the more likely they will be to recognize you. It's normal for betta fish to swim to the front of the tank when an owner comes up to it.
When sound vibrations pass through a fish, the differences in vibrations between the dense otoliths and the sensory hair cells is detected by the auditory nerves. In some fishes the gas bladder (sometimes called the swim bladder) aids in hearing by transmitting vibrations to the inner ear.
But barely, unless you are shouting. Sounds that are created above water typically do not carry enough force to penetrate the surface tension of the water, so talking on the boat or loud noise may not affect fish as much as your fellow anglers may want you to think. Your voice is unlikely to spook or scare fish away.
Nerves, brain structure, brain chemistry and behaviour – all evidence indicates that, to varying degrees, fish can feel pain, fear and psychological stress.
According to Balcombe, some fish (though certainly not all) do actually enjoy being touched by humans.
Fish-keepers sometimes see their pets 'glass surfing' – swimming repeatedly up and down the glass of the tank. This could be the aquatic equivalent of the pacing of a captive tiger that's bored from a lack of stimulation. But the fish could also be stressed from an overcrowded or unfamiliar tank.
Groupers are not the only fish that enjoy being petted, it seems. According to videos on YouTube, other species of fish that appear to like the interaction include koi, cichlid and discus fish.
Speaking to your fish also helps to strengthen your bond and helps you spend more time with them, which makes you a better fishkeeper.
Can your pet fish recognize your face? A new study says, Yes, it probably can. Researchers studying archerfish found the fish can tell a familiar human face from dozens of new faces with surprising accuracy.
Fish are attracted to certain sounds and vibrations and not to others. Certain types of music and sounds repel fish while others interest them. Music and other sounds can define the change in the way fish behave in the water, including their eating and swimming patterns.
Now, in a study described last November in Animal Behaviour, they have demonstrated that the fish can recognize the same face turned to the side by 30, 60 and 90 degrees—a nontrivial task.
The cerebral cortex and limbic system are absent in fish. Cerebral cortex, which is what permits other animals to cry.
While fish do not sleep in the same way that land mammals sleep, most fish do rest. Research shows that fish may reduce their activity and metabolism while remaining alert to danger. Some fish float in place, some wedge themselves into a secure spot in the mud or coral, and some even locate a suitable nest.
Tapping on fish tank glass scares fish simply because it bewilders and disorients them. They have no idea what's going on, and all of a sudden they hear an overwhelming tapping sound that's completely puzzling to them.
The same noise level in the air could lead to serious hearing damage over time. And fish have it even worse: since the sound pressure is four times higher under water than it is in the air, a good portion of deaths in public aquarium can be traced back to repeated tapping on the glass.
As well as getting water through osmosis, saltwater fish need to purposefully drink water in order to get enough into their systems. Where their freshwater counterparts direct all of the water that comes into their mouths out through their gills, saltwater fish direct some into their digestive tract.
Male kissers will occasionally challenge each other; however, the "kissing" itself is never fatal, but the constant bullying can stress the other fish to death. They often do in fact kill other fish by sucking the mucus off their skin as food, which opens the victim fish up to infections.
“Fish do feel pain. It's likely different from what humans feel, but it is still a kind of pain.” At the anatomical level, fish have neurons known as nociceptors, which detect potential harm, such as high temperatures, intense pressure, and caustic chemicals.
You probably already know that if your aquarium environment does not live up to the standards of your fish they are unlikely to thrive. You may be surprised to learn, however, that an environment that is too cramped or dull can actually cause your fish to become angry.
In captivity, it's strongly recommended that they should be kept at least in pairs, to provide companionship. If you watch fish in a tank, you'll see that they regularly engage with other fish. It's thought that solitary fish, much like solitary humans, may begin to suffer from depression and lethargy.
Fish living in the deep sea manage to navigate in complete darkness. It's not strictly 'seeing' but fish have rows of pressure-sensitive organs running down each side of their body called the lateral line, which allows them to sense nearby animals from the pressure changes in the water.