2006-07-11 05:54:27 · 12 answers · asked by Anonymous in Science & Mathematics ➔ Biology
Robjharley had a good post. Here are some things to note about some of the other posts.
Both fish and mammals have hearts.
Mammals always (with one exception) give birth to live young. Fish give birth to either live young or eggs, though even when they give birth to live young, their reproductive physiology is different from mammals.
Fish have gills and can live in the water all the time, mammals have lungs and must breathe air. Even marine mammals can drown in water. If a dolphin doesn't reach air frequently, he'll drown and die.
Most mammals, like the dolphin, are warm-blooded and maintain a constant body temperature no matter what their environment is. Fish are poikilothermic - their body temperature fluctuates with the temperature of their environment.
Mammals are always vertebrates (have a hard skeleton on the inside). Fish can either be vertebrates or not. Sharks have cartilage instead of a bony skeleton.
Mammals nurse their live young with milk. Mammals also have hair. Even dolphins have hair - just not a lot of it!
2006-07-11 14:23:42 · answer #1 · answered by sugarpine25 3 · 0⤊ 0⤋
Are Sharks Mammals
2016-10-28 17:41:12 · answer #2 · answered by ? 4 · 0⤊ 0⤋
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are dolphines and sharks considered mammals?
2016-02-05 19:54:07 · answer #3 · answered by ? 4 · 0⤊ 0⤋
Dolphins are mammals evolved from a land predator. It breathes air, has live young and can regulate it's body temperature (the warm/cold blooded idea isn't completely accurate as many reptiles can do this as well.)
Sharks are fish that first appeared some 200 million years ago. They have excellent smell and are pretty sentient for fish. Some species give live births and can regulate their body temperature.
Source: various Nature Documentaries
2006-07-15 07:55:10 · answer #4 · answered by jedisaurus 3 · 0⤊ 0⤋
My 12 year old son, a protege' of discovery channel says:
A shark is a fish because it moves it's tail left and right to move in the water.
A dolphin is a mammal with warm blood and a heart. It can move it's tail up and down.
He says a whole bunch of other details but this is the listeners condensed version!
2006-07-11 06:00:28 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Dolphins are mammals and sharks are fish.
Mammals give birth to live young and fish in general lay eggs.
2006-07-11 05:59:19 · answer #6 · answered by nickirae1 1 · 0⤊ 0⤋
Dolphins (the playful kind that like to giggle and whatnot) are mammals. They have lungs and are warm blooded.
Sharks and the sportfishy Dolphins are fish; These animals are gilled and cold blooded.
2006-07-11 05:57:49 · answer #7 · answered by MeteoMike 2 · 0⤊ 0⤋
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No. The main defining characteristic of mammals is mammary glands - the glands which produce milk to feed the young, and which give mammals their name. If an animal has mammary glands, it is a mammal, and if it doesn't, it isn't. There is no shark that has mammary glands - whoever told you some sharks nurse their young is seriously misinformed. Live birth does not make something a mammal. There are numerous non-mammals that give birth to live young, such as various snakes and lizards, and some mammals which lay eggs - the monotremes (the duck-billed platypus and echidnas).
2016-03-27 05:27:06 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Dolphins yes, sharks no.
Dolphins breath with lungs, sharks have gills and are cold-blooded
2006-07-11 06:01:12 · answer #9 · answered by robjharley 2 · 0⤊ 0⤋
Dolphins are mammals...they have lungs and are warm-blooded
Sharks are not...they have gills and are cold blooded
2006-07-11 05:58:56 · answer #10 · answered by PhizZingFree 4 · 0⤊ 0⤋