Another question on feeding

Hi all,

Can anyone help me with this: I've been unexpectantly given the job of
fish-feeder during a holiday, and the owners aren't reachable. Now I have
little knowledge about fish, and how to take care of them. Can anyone
identify the 2 types of fish swimming in this tank (see url's below), and
give me some clues as to how much to feed them? Today I took some food
between my fingers, and 'crushed' the food into the tank. I did that about
4 - 5 times.

http://www.xs4all.nl/~lindir/vis1.JPG
http://www.xs4all.nl/~lindir/vis2.JPG

Any help is much appreciated, especially by those fish. ;)

[coolchinchilla]

JP wrote:
> Can anyone help me with this: I've been unexpectantly given the job of
> fish-feeder during a holiday, and the owners aren't reachable. Now I have
> little knowledge about fish, and how to take care of them. Can anyone
> identify the 2 types of fish swimming in this tank (see url's below)

One important thing to know about feeding fish is that it is more
dangerous to feed them too much rather than too little. Uneaten
food decays and turns into ammonia which is very toxic to fish. So
always err on the side of too little. A fish can go a day or two
without food with minimal ill-effects so don't be afraid to be miserly.

> give me some clues as to how much to feed them? Today I took some food
> between my fingers, and 'crushed' the food into the tank. I did that about
> 4 - 5 times.

I think they look like African cichlids. I have a tank with 10
cichlids and I give them about 1 teaspoon or so of dry flakes once
per day.

Generally you need to feed them what they consume in 3-5 minutes.
Next time put in one teaspoon (one generous pinch of food) and look
at your watch. If they've eaten it all in 2 minutes or less, put in
another teaspoon. Oh yea, no need to crumble the flakes, they eat
'em big or little.

> Any help is much appreciated, especially by those fish. ;)

Remember LESS is BETTER in regards to food.

Good luck. I hope you can enjoy these fish as well as feed 'em. :-)

coolchinchilla

[Elaine T]

JP wrote:
> Hi all,
>
> Can anyone help me with this: I've been unexpectantly given the job of
> fish-feeder during a holiday, and the owners aren't reachable. Now I have
> little knowledge about fish, and how to take care of them. Can anyone
> identify the 2 types of fish swimming in this tank (see url's below), and
> give me some clues as to how much to feed them? Today I took some food
> between my fingers, and 'crushed' the food into the tank. I did that about
> 4 - 5 times.
>
> http://www.xs4all.nl/~lindir/vis1.JPG
> http://www.xs4all.nl/~lindir/vis2.JPG
>
> Any help is much appreciated, especially by those fish. ;)
>
>
As Coolchinchilla said, less is more. I agree that they're cichlids but
I'm also not sure which species. Those big, fat chichlids are in no
danger of starvation, but they'll likely try to fool you into thinking
otherwise. When you approach the tank, I bet you see a mad dash for
food, as if the fish have been starved for *months*.

I usually let a tank aggressive feeders eat for maybe 30 seconds;
sometimes less. So...put a small pinch of food in the tank and start
timing. If it's gone sooner, keep adding food, as long as they can eat
it in the rest of the 30 seconds. By the end of the 30 seconds, you
want no food left. That may be somewhat less than their usual owner
feeds, but it's better to go easy and keep the water good and clean.
Also, the fish will be fine fed once a day, or even every other day.

Good luck, and have fun watching them some!

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com

[Scott Far Thunder]

the large black and grey ones are convict cichlids..look to be all male from
the pictures - females have red/orange tinged abdomen..not sure about the
white guys. If the convicts are all indeed all males, you may need to make
separate "drops areas" in the tank to ensure everybody gets a fighting
chance at the food. IME convicts like most cichlids appear ravenous and can
be aggressive feeders; subdominant males and the smaller white cichlids may
be unwilling/unable to swim into a throng of feeding convicts. They'll eat
whole flakes, no reason to "crumble" them up
HTH

lila pilamaya

[Scott Far Thunder]

white guys may be pink convicts? same story as the other post.


<JP> wrote in message ...
> Hi all,
>
> Can anyone help me with this: I've been unexpectantly given the job of
> fish-feeder during a holiday, and the owners aren't reachable. Now I have
> little knowledge about fish, and how to take care of them. Can anyone
> identify the 2 types of fish swimming in this tank (see url's below), and
> give me some clues as to how much to feed them? Today I took some food
> between my fingers, and 'crushed' the food into the tank. I did that about
> 4 - 5 times.
>
> http://www.xs4all.nl/~lindir/vis1.JPG
> http://www.xs4all.nl/~lindir/vis2.JPG
>
> Any help is much appreciated, especially by those fish. ;)
>

[Derek Benson]

On Tue, 12 Jul 2005 17:32:58 +0200, <JP> wrote:

>Hi all,
>
>Can anyone help me with this: I've been unexpectantly given the job of
>fish-feeder during a holiday, and the owners aren't reachable. Now I have
>little knowledge about fish, and how to take care of them. Can anyone
>identify the 2 types of fish swimming in this tank (see url's below), and
>give me some clues as to how much to feed them? Today I took some food
>between my fingers, and 'crushed' the food into the tank. I did that about
>4 - 5 times.
>
>http://www.xs4all.nl/~lindir/vis1.JPG
>http://www.xs4all.nl/~lindir/vis2.JPG
>
>Any help is much appreciated, especially by those fish. ;)
>
They are Convict cichlids and White convicts as was mentioned. Feed
them as much as they can eat in about 2 minutes, twice a day or three
times a day. If there comes a day when you are there only once, so you
can feed them only once, do not increase the food amount so they're
eating for six minutes; still give them about 2 minute's worth of
food. I've owned a lot of Convict cichlids as I've bred them a number
of times.

-Derek

[Elaine T]

Derek Benson wrote:
> On Tue, 12 Jul 2005 17:32:58 +0200, <JP> wrote:
>
>
>>Hi all,
>>
>>Can anyone help me with this: I've been unexpectantly given the job of
>>fish-feeder during a holiday, and the owners aren't reachable. Now I have
>>little knowledge about fish, and how to take care of them. Can anyone
>>identify the 2 types of fish swimming in this tank (see url's below), and
>>give me some clues as to how much to feed them? Today I took some food
>>between my fingers, and 'crushed' the food into the tank. I did that about
>>4 - 5 times.
>>
>>http://www.xs4all.nl/~lindir/vis1.JPG
>>http://www.xs4all.nl/~lindir/vis2.JPG
>>
>>Any help is much appreciated, especially by those fish. ;)
>>
>
> They are Convict cichlids and White convicts as was mentioned. Feed
> them as much as they can eat in about 2 minutes, twice a day or three
> times a day. If there comes a day when you are there only once, so you
> can feed them only once, do not increase the food amount so they're
> eating for six minutes; still give them about 2 minute's worth of
> food. I've owned a lot of Convict cichlids as I've bred them a number
> of times.
>
> -Derek

Wow - that sounds like a lot of food! I've never kept convicts, though.

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com

[Derek Benson]

On Thu, 14 Jul 2005 23:32:59 GMT, Elaine T >
wrote:

>Derek Benson wrote:

>> They are Convict cichlids and White convicts as was mentioned. Feed
>> them as much as they can eat in about 2 minutes, twice a day or three
>> times a day. If there comes a day when you are there only once, so you
>> can feed them only once, do not increase the food amount so they're
>> eating for six minutes; still give them about 2 minute's worth of
>> food. I've owned a lot of Convict cichlids as I've bred them a number
>> of times.
>>
>> -Derek
>
>Wow - that sounds like a lot of food! I've never kept convicts, though.

Peter Hunnam writes in his book The Living Aquarium that fish should
be fed once or twice daily, the feeding period to last between 2 and 5
minutes with no food left uneaten in the tank at the end.

-Derek

[Elaine T]

Derek Benson wrote:
> On Thu, 14 Jul 2005 23:32:59 GMT, Elaine T >
> wrote:
>
>
>>Derek Benson wrote:
>
>
>>>They are Convict cichlids and White convicts as was mentioned. Feed
>>>them as much as they can eat in about 2 minutes, twice a day or three
>>>times a day. If there comes a day when you are there only once, so you
>>>can feed them only once, do not increase the food amount so they're
>>>eating for six minutes; still give them about 2 minute's worth of
>>>food. I've owned a lot of Convict cichlids as I've bred them a number
>>>of times.
>>>
>>>-Derek
>>
>>Wow - that sounds like a lot of food! I've never kept convicts, though.
>
>
> Peter Hunnam writes in his book The Living Aquarium that fish should
> be fed once or twice daily, the feeding period to last between 2 and 5
> minutes with no food left uneaten in the tank at the end.
>
> -Derek

Interesting. Thanks! I've been wondering if I'm a bit stingy with the
food. I'm going to time my feedings and see where I fall. I know for
sure that none of my fish get to eat for 5 minutes! Can you imagine how
much koi would eat in that time? ;-)

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com

[Gill Passman]

"Elaine T" > wrote in message
...
> Derek Benson wrote:
> > On Thu, 14 Jul 2005 23:32:59 GMT, Elaine T >
> > wrote:
> >
> >
> >>Derek Benson wrote:
> >
> >
> >>>They are Convict cichlids and White convicts as was mentioned. Feed
> >>>them as much as they can eat in about 2 minutes, twice a day or three
> >>>times a day. If there comes a day when you are there only once, so you
> >>>can feed them only once, do not increase the food amount so they're
> >>>eating for six minutes; still give them about 2 minute's worth of
> >>>food. I've owned a lot of Convict cichlids as I've bred them a number
> >>>of times.
> >>>
> >>>-Derek
> >>
> >>Wow - that sounds like a lot of food! I've never kept convicts, though.
> >
> >
> > Peter Hunnam writes in his book The Living Aquarium that fish should
> > be fed once or twice daily, the feeding period to last between 2 and 5
> > minutes with no food left uneaten in the tank at the end.
> >
> > -Derek
>
> Interesting. Thanks! I've been wondering if I'm a bit stingy with the
> food. I'm going to time my feedings and see where I fall. I know for
> sure that none of my fish get to eat for 5 minutes! Can you imagine how
> much koi would eat in that time? ;-)
>
> --
> Elaine T __
> http://eethomp.com/fish.html <'__><
> rec.aquaria.* FAQ http://faq.thekrib.com

I also think I might be a little stingy with the food - I feed twice a day
but it is usually gone within 30 secs - 1 minute maximum. However all the
fish look healthy and happy - with some very sad exceptions where the fish
have been algae eaters and would not accept any additional food - 2 ottos
and very sadly one Pl*c last night from my son's 30 gall :-( - lights out
policy to reduce heat has massacared the algae....I actually find it hard to
understand how a fish will just not eat rather than accepting alternatives
knowing that it will result in death - I would have thought that nature
would have given them a more tuned survival mechanism - anything better than
nothing....

Another thought that comes to mind is some mammals and especially humans
will over eat - so why assume that fish won't do the same. Obesity is a
large problem in Western Society and I'm not convinced that it is all down
to the wrong food - quantity perhaps rather than quality. The more you feed
someone/something then the larger the stomach capacity....

Gill

[Elaine T]

Rocco Moretti wrote:
> Elaine T wrote:
>
>> Derek Benson wrote:
>
>
>>> Peter Hunnam writes in his book The Living Aquarium that fish should
>>> be fed once or twice daily, the feeding period to last between 2 and 5
>>> minutes with no food left uneaten in the tank at the end.
>>>
>>> -Derek
>>
>>
>>
>> Interesting. Thanks! I've been wondering if I'm a bit stingy with
>> the food. I'm going to time my feedings and see where I fall. I know
>> for sure that none of my fish get to eat for 5 minutes! Can you
>> imagine how much koi would eat in that time? ;-)
>
>
> How do you deal with the timing method and a mixed tank? If I use flake
> food, the tetras (greedy buggers) eat it all before any get to the
> bottom, even if keep adding food for the two minutes - none makes it
> down to the corys. I have sinking pellets, but timing them doesn't work
> too well, as they take >2 minutes to soften enough for the corys to
> really get at them.
>
Good question. IMO catfish and sinking pellets are a completely
different story. When I used to keep cories, I think maybe I put in
half of a Hikari wafer for my three at lights out. I mostly keep
loaches now, and they learn to eat flake from the surface and in
midwater with the tetras. I need the loaches hunting snails so I don't
use any sinking food.

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com

[Derek Benson]

On Fri, 15 Jul 2005 14:17:16 -0500, Rocco Moretti
> wrote:

>Elaine T wrote:
>> Derek Benson wrote:
>
>>> Peter Hunnam writes in his book The Living Aquarium that fish should
>>> be fed once or twice daily, the feeding period to last between 2 and 5
>>> minutes with no food left uneaten in the tank at the end.
>>>
>>> -Derek
>>
>> Interesting. Thanks! I've been wondering if I'm a bit stingy with the
>> food. I'm going to time my feedings and see where I fall. I know for
>> sure that none of my fish get to eat for 5 minutes! Can you imagine how
>> much koi would eat in that time? ;-)
>
>How do you deal with the timing method and a mixed tank? If I use flake
>food, the tetras (greedy buggers) eat it all before any get to the
>bottom, even if keep adding food for the two minutes - none makes it
>down to the corys. I have sinking pellets, but timing them doesn't work
>too well, as they take >2 minutes to soften enough for the corys to
>really get at them.

If you're putting in a little flake food, it's gone in 20 seconds, so
you do a little more, gone in 20 seconds, them you add a little more,
etc., what you should do is put it all in at the start, all at once.
You do this by looking at the amount of flake spreading on the water,
simply judge the amount to put in. The more flake put in at the start,
the better chance that some of it is going to sink down past the other
fish to the corys. It's no problem to make this judgement with a
little practice with your specific fish, without putting in way too
much.

Otherwise you might try putting the pellets in water in a spoon for a
couple minutes so they soak up water and soften, then dump them in the
tank.

-Derek

[NetMax]

"Gill Passman" <gillspamattaylorpassmanspam.co.uk> wrote in message
.. .
>
> "Elaine T" > wrote in message
> ...
>> Derek Benson wrote:
>> > On Thu, 14 Jul 2005 23:32:59 GMT, Elaine T >
>> > wrote:
>> >
>> >
>> >>Derek Benson wrote:
>> >
>> >
>> >>>They are Convict cichlids and White convicts as was mentioned. Feed
>> >>>them as much as they can eat in about 2 minutes, twice a day or
>> >>>three
>> >>>times a day. If there comes a day when you are there only once, so
>> >>>you
>> >>>can feed them only once, do not increase the food amount so they're
>> >>>eating for six minutes; still give them about 2 minute's worth of
>> >>>food. I've owned a lot of Convict cichlids as I've bred them a
>> >>>number
>> >>>of times.
>> >>>
>> >>>-Derek
>> >>
>> >>Wow - that sounds like a lot of food! I've never kept convicts,
>> >>though.
>> >
>> >
>> > Peter Hunnam writes in his book The Living Aquarium that fish should
>> > be fed once or twice daily, the feeding period to last between 2 and
>> > 5
>> > minutes with no food left uneaten in the tank at the end.
>> >
>> > -Derek
>>
>> Interesting. Thanks! I've been wondering if I'm a bit stingy with
>> the
>> food. I'm going to time my feedings and see where I fall. I know for
>> sure that none of my fish get to eat for 5 minutes! Can you imagine
>> how
>> much koi would eat in that time? ;-)
>>
>> --
>> Elaine T __
>> http://eethomp.com/fish.html <'__><
>> rec.aquaria.* FAQ http://faq.thekrib.com
>
> I also think I might be a little stingy with the food - I feed twice a
> day
> but it is usually gone within 30 secs - 1 minute maximum. However all
> the
> fish look healthy and happy - with some very sad exceptions where the
> fish
> have been algae eaters and would not accept any additional food - 2
> ottos
> and very sadly one Pl*c last night from my son's 30 gall :-( - lights
> out
> policy to reduce heat has massacared the algae....I actually find it
> hard to
> understand how a fish will just not eat rather than accepting
> alternatives
> knowing that it will result in death - I would have thought that nature
> would have given them a more tuned survival mechanism - anything better
> than
> nothing....
>
> Another thought that comes to mind is some mammals and especially
> humans
> will over eat - so why assume that fish won't do the same. Obesity is a
> large problem in Western Society and I'm not convinced that it is all
> down
> to the wrong food - quantity perhaps rather than quality. The more you
> feed
> someone/something then the larger the stomach capacity....
>
> Gill


Why feed fish? (rhetorical question) I think that most of the energy
people get from eating goes towards temperature regulation and
locomotion. Fish keep their internal temperature close to the ambient
water, so relatively little energy is required for that, and most fish
are 100% buoyant to the ambient water so relatively little energy is used
getting around. They really don't need as much food as most people
think (using themselves for comparison).

With less food, the water, gravel and filters will stay cleaner. Taken
to an extreme, the fish will have less reserve energy, colors not as
bright and may become aggressive towards tank-mates (could be an early
issue with a tank of convicts).

One of the most critical and hardest things to teach new employees at the
pet shop was how much (and what) to feed the fish. In a commercial tank,
you want to be closer to the overfeeding extreme, as you want fast
growth, fast color recovery, good energy reserves for fighting diseases,
and can compensate for the extra pollution by overfiltering and massive
frequent water changes.

In the home tank (lower filtration, less disease vectors, and no
employees to do your maintenance ;~), I think you want to be closer to
the underfeeding extreme, but use a greater variety of foods to
compensate for any potential nutrient deficiencies. jmo
--
www.NetMax.tk

[Dr Engelbert Buxbaum]

<JP> wrote:


> give me some clues as to how much to feed them? Today I took some food
> between my fingers, and 'crushed' the food into the tank. I did that about
> 4 - 5 times.

As a general rule a fishs stomach is about the size of its eyes. That
limits the amount of food they can consume in one go. Excess food will
decompose and foul the water. Remember that fish are cold-blooded and
don't need to spend a lot of energy on maintaining their body
temperature like us mammals do. So, as others have said, give as much
food as can be consumed in a few minutes and don't sweat it.

[NetMax]

"Dr Engelbert Buxbaum" > wrote in message
...
> <JP> wrote:
>
>
>> give me some clues as to how much to feed them? Today I took some food
>> between my fingers, and 'crushed' the food into the tank. I did that
>> about
>> 4 - 5 times.
>
> As a general rule a fishs stomach is about the size of its eyes. That
> limits the amount of food they can consume in one go. Excess food will
> decompose and foul the water. Remember that fish are cold-blooded and
> don't need to spend a lot of energy on maintaining their body
> temperature like us mammals do. So, as others have said, give as much
> food as can be consumed in a few minutes and don't sweat it.


A technicality I've been corrected on in the past is that fish are not
classified as cold-blooded, but as poikilothermic ectotherms (which I
presume to mean that they do have some ability to regulate their
temperature, so are not true 'cold-bloods'). My point is only educational
trivia, and not critiquing of course.
--
www.NetMax.tk

[Rocco Moretti]

NetMax wrote:

> A technicality I've been corrected on in the past is that fish are not
> classified as cold-blooded, but as poikilothermic ectotherms (which I
> presume to mean that they do have some ability to regulate their
> temperature, so are not true 'cold-bloods'). My point is only educational
> trivia, and not critiquing of course.

Wikipedia indicates that "poikilothermic ectotherms" *are* the same as
"cold blooded" (http://en.wikipedia.org/wiki/Cold-blooded)

On the "warm blooded" page (http://en.wikipedia.org/wiki/Warm-blooded)
they mention that Tuna and Swordfish are able to regulate temperature
above ambient by heat exchange mechanisms.

[NetMax]

"Rocco Moretti" > wrote in message
...
> NetMax wrote:
>
>> A technicality I've been corrected on in the past is that fish are not
>> classified as cold-blooded, but as poikilothermic ectotherms (which I
>> presume to mean that they do have some ability to regulate their
>> temperature, so are not true 'cold-bloods'). My point is only
>> educational trivia, and not critiquing of course.
>
> Wikipedia indicates that "poikilothermic ectotherms" *are* the same as
> "cold blooded" (http://en.wikipedia.org/wiki/Cold-blooded)
>
> On the "warm blooded" page (http://en.wikipedia.org/wiki/Warm-blooded)
> they mention that Tuna and Swordfish are able to regulate temperature
> above ambient by heat exchange mechanisms.

I wish I could debate the point, but I'd rather you thought I was wrong,
than open my mouth further to confirm it ;~).
--
www.NetMax.tk

[Rocco Moretti]

NetMax wrote:
> "Rocco Moretti" > wrote in message
> ...
>
>>NetMax wrote:
>>
>>
>>>A technicality I've been corrected on in the past is that fish are not
>>>classified as cold-blooded, but as poikilothermic ectotherms (which I
>>>presume to mean that they do have some ability to regulate their
>>>temperature, so are not true 'cold-bloods'). My point is only
>>>educational trivia, and not critiquing of course.
>>
>>Wikipedia indicates that "poikilothermic ectotherms" *are* the same as
>>"cold blooded" (http://en.wikipedia.org/wiki/Cold-blooded)
>>
>>On the "warm blooded" page (http://en.wikipedia.org/wiki/Warm-blooded)
>>they mention that Tuna and Swordfish are able to regulate temperature
>>above ambient by heat exchange mechanisms.
>
>
> I wish I could debate the point, but I'd rather you thought I was wrong,
> than open my mouth further to confirm it ;~).

I know less than you do. I only point out the Wikipedia links 'cause I
never heard of "poikilothermic ectotherms" before, and those articles
seem reasonably informative (for others who have never heard them either).

At the very least, we can probably agree that fish can be more
interesting than many people may first think.

[Elaine T]

Rocco Moretti wrote:
> NetMax wrote:
>
>> "Rocco Moretti" > wrote in message
>> ...
>>
>>> NetMax wrote:
>>>
>>>
>>>> A technicality I've been corrected on in the past is that fish are
>>>> not classified as cold-blooded, but as poikilothermic ectotherms
>>>> (which I presume to mean that they do have some ability to regulate
>>>> their temperature, so are not true 'cold-bloods'). My point is only
>>>> educational trivia, and not critiquing of course.
>>>
>>>
>>> Wikipedia indicates that "poikilothermic ectotherms" *are* the same
>>> as "cold blooded" (http://en.wikipedia.org/wiki/Cold-blooded)
>>>
>>> On the "warm blooded" page
>>> (http://en.wikipedia.org/wiki/Warm-blooded) they mention that Tuna
>>> and Swordfish are able to regulate temperature above ambient by heat
>>> exchange mechanisms.
>>
>>
>>
>> I wish I could debate the point, but I'd rather you thought I was
>> wrong, than open my mouth further to confirm it ;~).
>
>
> I know less than you do. I only point out the Wikipedia links 'cause I
> never heard of "poikilothermic ectotherms" before, and those articles
> seem reasonably informative (for others who have never heard them either).
>
> At the very least, we can probably agree that fish can be more
> interesting than many people may first think.

NetMax is right. Here's a good link that explains it better.
http://www.straightdope.com/mailbag/mwarmblood.html Poikilotherms
experience a lot of fluctuation in body temps, while homeotherms hold
temps at a steady level. Endotherms generate their own heat while
ectotherms match the temperature of their environment. Most ectotherms,
including fish, are poikilothermic. However, there are some critters
like desert lizards which are homeothermic ectotherms - they maintain a
constant daytime body temperature through basking.

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com

[Dr Engelbert Buxbaum]

NetMax wrote:

> "Dr Engelbert Buxbaum" > wrote in message
> ...
> > Remember that fish are cold-blooded and
> > don't need to spend a lot of energy on maintaining their body
> > temperature like us mammals do.
>
> A technicality I've been corrected on in the past is that fish are not
> classified as cold-blooded, but as poikilothermic ectotherms (which I
> presume to mean that they do have some ability to regulate their
> temperature, so are not true 'cold-bloods'). My point is only educational
> trivia, and not critiquing of course.
>

The expression "cold-blooded" is outdated because technically incorrect:
their blood is not generally cold, but follows the temperature of their
environment (ecto = outside). So if the water is warm, the fish
(including its blood) will be too. That is what those foreign terms
(derived from Greek) refer too. Mammals and birds are different, they
actively regulate their temperature and keep it at a constant value,
independent of the environment.

However justified these phrases may be in a scientific paper I find that
in a discussion with lay-persons the old expressions cold- and
warm-blooded are good enough.

[NetMax]

"Dr Engelbert Buxbaum" > wrote in message
...
> NetMax wrote:
>
>> "Dr Engelbert Buxbaum" > wrote in message
>> ...
>> > Remember that fish are cold-blooded and
>> > don't need to spend a lot of energy on maintaining their body
>> > temperature like us mammals do.
>>
>> A technicality I've been corrected on in the past is that fish are not
>> classified as cold-blooded, but as poikilothermic ectotherms (which I
>> presume to mean that they do have some ability to regulate their
>> temperature, so are not true 'cold-bloods'). My point is only
>> educational
>> trivia, and not critiquing of course.
>>
>
> The expression "cold-blooded" is outdated because technically incorrect:
> their blood is not generally cold, but follows the temperature of their
> environment (ecto = outside). So if the water is warm, the fish
> (including its blood) will be too. That is what those foreign terms
> (derived from Greek) refer too. Mammals and birds are different, they
> actively regulate their temperature and keep it at a constant value,
> independent of the environment.
>
> However justified these phrases may be in a scientific paper I find that
> in a discussion with lay-persons the old expressions cold- and
> warm-blooded are good enough.


Agreed, however these trips into the technical arenas are IMO entertaining
too. In regards to 'cold-blooded', my reference was not the wordage, but
because I thought that tropical fish have some ability to heat their blood,
while true cold-blooded creatures cannot. After several days of the water
temperature being different from usual, their blood then adjusts to the new
ambient. This buffers their internal organs from the effects of spending
several hours at different depths (and temperatures) while foraging.
However when I looked again, I couldn't find the scientific data to support
this, so I might be mistaken.
--
www.NetMax.tk

[Dr Engelbert Buxbaum]

NetMax wrote:


> Agreed, however these trips into the technical arenas are IMO entertaining
> too.

Definetly ;-)

> In regards to 'cold-blooded', my reference was not the wordage, but
> because I thought that tropical fish have some ability to heat their blood,
> while true cold-blooded creatures cannot. After several days of the water
> temperature being different from usual, their blood then adjusts to the new
> ambient. This buffers their internal organs from the effects of spending
> several hours at different depths (and temperatures) while foraging.
> However when I looked again, I couldn't find the scientific data to support
> this, so I might be mistaken.

Never heard of that story either. Something like that happens in insects
when they "pump" with their wings on a cold morning, so that the waste
heat warms them up enough for flying. But in aquatic organisms the high
heat conductivity of water would probably make that inefficient.

Very large cold-blooded animals can keep an elevated body temperature
simply because the increased volume/surface ratio, the metabolic heat in
the body can no longer be radiated to the environment completely
(gigantothermia). This is discussed for certain carnivorous dinos, to
explain their apparent agility. But it is certainly not important for
our charges ;-)