Are fish deaf?

[dohpin]

I have a tank of tropical fish. I wonder if they can hear. I hope someone
would tell me. Thank you.

[jduprie]

well, I guess it depends on what you mean by deaf. Fish do have "ears", and
an auditory nerve, but they're not really wha we would think of as ears. The
don't have the little bones, eardrum etc that most land animals have.
Land animals have all that stuff to act as amplifiers - the energy that
sound waves have in air is very low (comapred to what they carry in water),
so we need to be able to detect the tiniest waves. Fish (and a lot of other
marine critters) don't need all that - water is a very efficient energy
transfer media (compared to air), so they (fish) don't need as much "help"
to detect sound waves. (actually, they're just waves of energy - we inerpret
them as sound, but read on...). So, do they "hear" or not..... Imagine
you're at a big rock concert, and you're standing right infront of the giant
stack of bass speakers. You can hear the bass, but you can also feel it. If
you were deaf, you'd still be able to feel the bass rythm. Thats kind of
what fish get. They have a series of specialized cells (that are almost
identical to the sensory cells (called hair cells) in our ears. the big
difference is that we interpret the energy as sound only. Fish can use it
for a lot more. They can detect another fish swimming by - not because it
makes any noise, but because the waves made by its fins in the water can be
detected by the hair cells. If you look carefully at the head of a fish,
you'l see a series of lines, and probably one going along the body too.
Thats called the lateral line system, and its where al of these hair cells
are. Its been a long time since I studied this, but I *think* the
innervation for the lateral line is the auditory nerve (same nerve as our
ears). The cell types are the same, they operate the same way
physiologically, etc.....

So do fish hear? depends on what you mean by hearing....

hope this helps

--JD


"dohpin" > wrote in message
...
> I have a tank of tropical fish. I wonder if they can hear. I hope someone
> would tell me. Thank you.
>
>

[Dave Engle]

"jduprie" > wrote in message
news:_UEDb.63831$8y1.251251@attbi_s52...
> hope this helps

I don't know if you helped the original poster, but I found it
extremely interesting. Thanks!
--
~~~~~~~~~~~~~~~~~~~~~~~~
CingularDuality
TacticalGamer.com Administration
http://www.TacticalGamer.com

[dohpin]

Yes, it did help. Thanks a lot, jd!

"Dave Engle" > ¼¶¼g©ó¶l¥ó
...
> "jduprie" > wrote in message
> news:_UEDb.63831$8y1.251251@attbi_s52...
> > hope this helps
>
> I don't know if you helped the original poster, but I found it
> extremely interesting. Thanks!
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~
> CingularDuality
> TacticalGamer.com Administration
> http://www.TacticalGamer.com
>
>

[Tedd Jacobs]

"jduprie" wrote...
> well, I guess it depends on what you mean by deaf.

<snip>

well done!

is that why i'm not supposed to do this...

*tap* *tap* *tap*
"here fishy fishy fishy"
*tap* *tap* *tap*...

;-)

[jduprie]

Hmmm.. that would be it. Imagine standing in front of The Who's entire amp
and PA gig, set up in a parabolic arc, with you at teh focus. Now imagine
its cranked all the way up, and somebody starts a hard rythm on the bass
drum. (of course, they're also saying "here Tedd, Here Tedd"....

After you pick yourself up from the floor (and your eardrums stop bleeding)
you'll understand why the fish all spaz when you tap the glass......


('course I can rememeber when I willingly paid lots of money to sit in front
of their stacks for hours ata time....)

-_JD

"Tedd Jacobs" > wrote in message
...
>
> "jduprie" wrote...
> > well, I guess it depends on what you mean by deaf.
>
> <snip>
>
> well done!
>
> is that why i'm not supposed to do this...
>
> *tap* *tap* *tap*
> "here fishy fishy fishy"
> *tap* *tap* *tap*...
>
> ;-)
>
>