Is a shark a fish or a mammal?

A shark is a fish; it "breathes" its oxygen by passing water over its gills.

http://www.extremescience.com/BiggestFish.htm

Happy now ? :P

...Cheers bud :D

Originally posted by spyro2000
...Cheers bud :D


Was it one of those things that does your head in till you know the answer?


:loopy:

Originally posted by Mod2
Was it one of those things that does your head in till you know the answer?


:loopy:

lol it was actually. I was having a convo with a mate about animal fights (dont ask) and for some reason it came into conversation about fishes, and I couldnt remember if its a whale that is a fish or a shark, I knew it was one or the other

even more interestingly, it is an elesmobranch. Used to work at the London Aquarium...

Originally posted by lizzmobile
even more interestingly, it is an elesmobranch. Used to work at the London Aquarium...

er .... would that be elasmobranch? Used to work as a pedant....


I'll get my coat, then.

Originally posted by spyro2000
lol it was actually. I was having a convo with a mate about animal fights (dont ask) and for some reason it came into conversation about fishes, and I couldnt remember if its a whale that is a fish or a shark, I knew it was one or the other

this didn't involve a crocodile and a shark did it?:suspect:

i do know sharks cant stop moving or they drown

Originally posted by robbie
this didn't involve a crocodile and a shark did it?:suspect:

It didnt no. And how a croc and a shark could fight anyway is beyond me. :confused:

Originally posted by spyro2000
It didnt no. And how a croc and a shark could fight anyway is beyond me. :confused:

There are,of course,species of crocodile which live in the sea.I dont know if anyone saw it,but there was a program on the discovery channel featuring 'what if' fights between animals.One episode was about a sea croc Vs a great white-the great white won,but for me the croc was robbed:suspect:

after one day of democratic discussion through several home office departments we reckon that the Croc would win.

Originally posted by robbie
after one day of democratic discussion through several home office departments we reckon that the Croc would win.

I would agree,but the Shark has friends in high places....:D

Wouldn't the shark have friends in low places?

Huh, like most sharks do.
(yes, elasmobranch, typo :wink: )

Originally posted by melthebell
i do know sharks cant stop moving or they drown
some sharks.

Many common sharks rest on the seafloor, without dying.


And a shark is not a fish. No swim bladder, no gill covers, no bones - only cartilage, no spine, only a notochord.

Originally posted by Phanerothyme
some sharks.

Many common sharks rest on the seafloor, without dying.


And a shark is not a fish. No swim bladder, no gill covers, no bones - only cartilage, no spine, only a notochord.

Hey Phan, we've been here before. Wasn't this very subject one of the first arguments, sorry, discussions we ever had? ;)

It went something like this: There are more than one order of sharks. Sharks are found in the Class Chondrichthyes (cartilaginous fishes) and under the Subclass Elasmobranchii (sharklike fishes)

Will a boy ever be born who can swim faster than a shark?

Originally posted by mojoworking
Hey Phan, we've been here before. Wasn't this very subject one of the first arguments, sorry, discussions we ever had? ;)

It went something like this: There are more than one order of sharks. Sharks are found in the Class Chondrichthyes (cartilaginous fishes) and under the Subclass Elasmobranchii (sharklike fishes)

We never debated classes of chordates...it was simply a discussion of whether sharks need to swim to live.

I think we left it with you saying most sharks need to swim in order to survive. I would say most sharks don't.

I didn't have the figures on how many sharks (species or individuals) have this requirement, but I do know that some of the most common species of shark laze on the bottom without swimming forwards, so in terms of numbers I believe I am right.

In terms of species I''d like to see the figures before I agreed that indeed most species of sharks (i.e over 50% of species) need to swim in order to live. I suspect the opposite.


As far as sharks being fish - I concede that they are, but they are as different from true fish as squid or penguins or whales.

Animalia Chordata Osteichthyes - True Fish
Animalia Chordata Chondrichthyes - Sharks
Animalia Chordata Aves - Penguins
Animalia Chordata Mammalia - Whales

Fair enough, I am using the von Linné taxonomic term for birds, because taxonomy seems something of a mess where they are concerned. So yes, sharks are a kind of fish. And so are True Fish (like salmon), and Jawless Fish (hagfish).

Originally posted by sammyBoy
Will a boy ever be born who can swim faster than a shark?

Considering the fastest sharks can hit 50 mph, probably not.

Originally posted by Phanerothyme
We never debated classes of chordates...it was simply a discussion of whether sharks need to swim to live.

I think we left it .................................................. ..............................And so are True Fish (like salmon), and Jawless Fish (hagfish).


Never get just a yes/no answer from you phan.

Keep it up!:D like to learn something new everyday.

I was told a few weeks back that a shark is a marine mamal. I am not sure this is correct. i have always thought they are fish.

Originally posted by Phanerothyme
Animalia Chordata Osteichthyes - True Fish
Animalia Chordata Chondrichthyes - Sharks
Animalia Chordata Aves - Penguins
Animalia Chordata Mammalia - Whales
Wow, amazing - I never knew that. I presume the "animalia chordata" part means they're vertebrates, I was taught at school that there are only five classes of vertebrates: fish, amphibians, reptiles, birds and mammals. Does this mean there are six? Are there others I don't know about?

And is a shark really a vertebrate, if it's cartilaginous and hence doesn't have a back "bone"?

Kingdom Animalia has 35 phyla including:

Phylum Chordata: (3 Subphyla)

Subphylum Urochordata
Subphylum Cephalachordata
Subphylum Vertebrata (7 Classes)

Class Agnatha: Fish lacking jaws
Class Chondrichthyes: Cartilaginous fish
Class Osteichthyes: Bony fish
Class Amphibia: Amphibians, adapted to terrestrial and aquatic environments
Class Reptilia: Reptiles, descendants of amphibians adapted to living on land alone
Class Aves: The birds
Class Mammalia: The mammals, a diverse class with hair and mammary glands

The Class Chondrichthyes has two sub-classes, one being Elasmobranchia which contains the sharks.

ooh i'm lost

again :rolleyes:

Originally posted by sammyBoy
Will a boy ever be born who can swim faster than a shark?

“I could catch a monkey. If I was starving I could. I’d make poison darts out of the poison of the deadly frogs. One milligram of that poison can kill a monkey. Or a man. Prick yourself and you’d be dead within a day. Or longer. Different frogs, different times.”

Originally posted by cgksheff
Kingdom Animalia has 35 phyla including:

Phylum Chordata: (3 Subphyla)

Subphylum Urochordata
Subphylum Cephalachordata
Subphylum Vertebrata (7 Classes)

...


The Class Chondrichthyes has two sub-classes, one being Elasmobranchia which contains the sharks.

However, taxonomy is an art not a science :) I think they make it up as they go along from a sensible but flawed basis laid down by Carl von Linné

But sharks are definitely not mammals.