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.
Aquarium fish don't exactly see in pitch-black darkness. But they can, of course, use their lateral line system to search for prey or find food to nibble on even in the dark. If your tank's inhabitants are nocturnal feeders, you can safely feed them just after turning off your aquarium's lights.
Fish don't like the dark because when there is no light to see, they dart around the tank, colliding with the walls, ornaments and can even become tangled in the plants. Fish need light to determine whether it is night or day, and they're scared of the sudden switch from darkness to light.
Aquarium fish can sense their environment in the dark using their lateral lines, but most species can't “see” in the dark, and all species need a light/dark cycle. While fish see — and sleep — differently than we do, they can still perceive waves of light underwater, and light is still important to their well-being.
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.
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.
Nerves, brain structure, brain chemistry and behaviour – all evidence indicates that, to varying degrees, fish can feel pain, fear and psychological stress.
Fish do not need light at night. A period of darkness is necessary for the fish to sleep. Also, leaving the lights on all night could cause algae to rapidly grow and take over your aquarium. That for sure is an unwanted and ugly looking result.
Fish are not as reliant on light as plants. In general, aquarium owners can use incandescent, fluorescent, or LED lights for fish but should be aware of the heat issues that incandescent lights cause.
Keep in mind that not all fish will like the same light and dark periods. Fish will sleep and having a slow increase in light is better than a sudden switch. Some species will like to “sleep in” and hide out in their caves for awhile until their eyes adjust.
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.
The cerebral cortex and limbic system are absent in fish. Cerebral cortex, which is what permits other animals to cry.
Researchers studying archerfish found the fish can tell a familiar human face from dozens of new faces with surprising accuracy. This is a big, big deal. It's the first time fish have demonstrated this ability.
Aquarium fish do not need light and it is best that you turn it off during the night. Leaving the light on can cause stress to fish as they need a period of darkness to sleep. Too much light will cause algae to rapidly grow and make your tank look dirty. So the short answer is no, do not leave your lights on.
Any light under the water, no matter what the color, will attract fish. When lights are placed under the water, they reflect off particles in the water.
It's more fun and comfortable. The moon phase and the tides play a huge role but many fish species are active at night. Fish become more active when there's light and that means it'll be easier for them to find a bait. That's why anglers claim that it's not a good idea to fish the day following a full moon.
Cool color lights like purple, blue, red, and green are the best choices for betta fish. They tend to give the fish the sensation of their natural habitat as well as keep them calm and relaxed.
FULL RGB SPECTRUM
This is our go-to spectrum and we HIGHLY recommend this spectrum for most freshwater aquariums. Nothing brings out the vivid colors and enhances your tank like a full, rich RGB (Red,Green,Blue) spectrum of light. It not only makes your fish pop in color, it also won't promote algae growth.
Begin by feeding the fish the amount you usually do, and see if they eat all the food within four or five minutes. Gradually reduce the amount of food you give the fish until they finish the feeding in the appropriate amount of time. If there is ever food left in the tank, remove uneaten food with a net or siphon.
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.
When choosing a light source for night fishing, the best color to use and attract fish is green or a mixture of green and white. These colors can penetrate around 70 to 75 feet deep underwater.
How long should I keep my aquarium lights on? To provide animals and plants the lighting they need, 10 to 12 hours a day is sufficient. Installing a timer or purchasing a unit with integrated timing can make lighting easier––just set it and forget it.
Surprisingly, science has found that fish are capable of recognizing their owner's face, even if the owner is standing by the tank with other people. Fish can develop an association between something they like, being fed, with the person who feeds them.
According to Balcombe, some fish (though certainly not all) do actually enjoy being touched by humans.
Fish have nerves, just like cats, dogs, and humans, so they can feel pain. Hooked fish endure not only physical pain but also terror. When they're removed from their natural environment, they start to suffocate. Just imagine the horrible feeling you'd experience if you were trapped underwater.