fish, any of approximately 34,000 species of vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world. Living species range from the primitive jawless lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes.
How many fish species are there in the world?
Summary. There are more than 35,000 identified and described fish species in the world.
Are fish considered creatures?
Fishes are a group of animals that are completely aquatic vertebrates that have gills, scales, swim bladders to float, most produce eggs, and are ectothermic.
Do fish have feelings?
Fish have emotions, social needs, and intelligence. Meet scientists exploring the inner lives of our aquatic friends.
Is Octopus a fish?
Yes, a mollusk — like your common garden snail. To be more specific, an octopus belongs to a unique class of mollusks known as cephalopods. … To put it in simpler terms, this why an octopus has no bones — no skeleton — it is an invertebrate. A fish has a backbone and a skeleton — it is a vertebrate.
Do fishes fart?
Most fish do use air to inflate and deflate their bladder to maintain buoyancy which is expelled either through their mouth or gills which can be mistaken for a fart. … Experts say that the digestive gases of fish are consolidated with their feces and expelled in gelatinous tubes which fish sometimes eat again (eew…
Do fishes pee?
Freshwater fish will passively intake water from their environment and then, as their insides are saltier than their surroundings, will excrete a diluted urine. … Fish have kidneys which produce urine containing ammonium, phosphorus, urea, and nitrous waste.
Which fish is the best for health?
- Alaskan salmon. There’s a debate about whether wild salmon or farmed salmon is the better option. …
- Cod. This flaky white fish is a great source of phosphorus, niacin, and vitamin B-12. …
- Herring. A fatty fish similar to sardines, herring is especially good smoked. …
- Mahi-mahi. …
- Mackerel. …
- Perch. …
- Rainbow trout. …
- Sardines.
Is a shark a fish or a mammal?
Sharks are fish. They live in water, and use their gills to filter oxygen from the water. Sharks are a special type of fish known because their body is made out of cartilage instead of bones like other fish.
Do vegetarians eat fish?
Vegetarians do not eat the flesh of animals. … Some vegetarians, known as lacto-ovo-vegetarians, eat certain animal products, such as eggs, milk, and cheese. Still, they do not eat fish. If vegetarians include fish and seafood in their diets but still avoid the flesh of other animals, they’re considered pescatarians.
Is a fish an mammal?
Fish are not mammals because most of them are not warmblooded, though some sharks and species of tuna are exceptions. They do not have limbs, fingers, toes, fur, or hair, and most of them can’t breathe air, though the lungfish and the snakehead are also exceptions.
Why are fish not real?
That’s according to a group of scientists nicknamed cladists for their support of a scientific classification system of species based on clades. … A clade is a fancy term for all of and only the modern species descended via evolution from a specific common ancestor.
What is fish in genetics?
Fluorescence in situ hybridization (FISH) provides researchers with a way to visualize and map the genetic material in an individual’s cells, including specific genes or portions of genes. This may be used for understanding a variety of chromosomal abnormalities and other genetic mutations.
Is a starfish a fish?
Sea stars, commonly called, “starfish,” are not fish.
They do not have gills, scales, or fins. … Tube feet also help sea stars hold their prey. Sea stars are related to sand dollars, sea urchins, and sea cucumbers, all of which are echinoderms, meaning that they have five-point radial symmetry.
Do fishes cry?
Fish yawn, cough, and even burp. … “Since fishes lack the parts of the brain that set us apart from the fishes — the cerebral cortex — I doubt very much that fishes engage in anything like crying,” Webster told LiveScience. “And certainly they produce no tears, since their eyes are constantly bathed in a watery medium.”
Do fish get thirsty?
The answer is still no; as they live in water they probably don’t take it in as a conscious response to seek out and drink water. Thirst is usually defined as a need or desire to drink water. It is unlikely that fish are responding to such a driving force.
Do fish poop out of their mouths?
You may be wondering how fish poop and pee, when there is no visible anus or opening apart from their mouth. … How do Fish poop and pee? Fish pee and poo through their gills and skin. Some also pee and poop through a small opening known as a pore, located at the body’s rear end.
Do mermaids fart?
Mermaids’ Mammalian Anatomy Farts
Based on the direction of the tail movement—mammals move their tails up and down while fish move their tails back and forth—mermaids are mammals and would have the internal digestive track of a mammal. Since nearly all mammals fart, then mermaids would fart, too.
Can spiders fart?
This happens a number of times, as spider digestive systems can only handle liquids—which means no lumps! … Since the stercoral sac contains bacteria, which helps break down the spider’s food, it seems likely that gas is produced during this process, and therefore there is certainly the possibility that spiders do fart.
Do fish get bored in tanks?
Just like any other pet, fish can become bored, too. … The key is to play off of what fish already do naturally. Adding things into their tanks that will occupy them and hone their natural instincts is a sure-fire way to have healthier happier fish that are more interesting to watch.
Is it wrong to eat octopus?
Countries that eat the most octopus are Korea, Japan and Mediterranean countries where they are considered a delicacy. … Octopus farming is cruel and immoral and this barbaric practice is condemned by both animal rights activists and many scientists.
Is octopus healthy to eat?
Heart Health
Octopus is an excellent source of omega-3 fatty acids, “good fats” linked to a range of heart-healthy benefits. Omega-3s can lower your blood pressure and slow the buildup of plaque in your arteries, reducing stress on the heart.
Why is whale a mammal and not a fish?
Mammals all are warm-blooded animals, they breathe air, have hair, and moms feed their babies milk from mammary glands. Whales actually do all of these things! Whales are warm blooded, which means they keep a high body temperature that does not change in the cold water. … So whales are indeed mammals and not fish!