Re: NANFA-- do fish get goiters?

Todd Crail (
Tue, 21 Jan 2003 12:53:29 -0500

Now my interest is really peaked. My feeding response for Geoff was more
based on "If that's the problem, then this should fix it". I had a faint
recollection of the endostyle from Developmental Biology, but I was very
unsure about any of that (and too lazy to grab my book :). At any rate,
here's where I'm going next...

I did my daily 4:00am wake up and the lightbulb went on over my head,
exploded, and then I went back to sleep ;)

Marine systems are *rich* in Iodine, and the organisms that live there
utilize this thru the food chain by phytoplankton utilizing it, zooplankton
eating the phyto, and then forward and up. There's no way to avoid it in
biopathways for these critters. It doesn't suprise me that trouble arose
in animals that live in Iodine enhanced systems would need extra, and how
they're the ones who show trouble first (ie we're not replicating their true
food chain). Some/Most? pupfish are living in water holes where water comes
in and doesn't go out regularly... It makes sense that they would have an
Iodine rich diet available from the food chains that errupt in these

So that makes sense to me... What I wonder is... How freshwater organisms
have dealt with leaving the marine systems and the consequential loss of
Iodine in their diet, due to the majority of it getting swept away? *Or*
perhaps we've not recognized how essential lower levels of Iodine and other
nutrients biofixed by phytoplankton and algaes are in their diet.

Question 1) Anyone familiar with any studies on the inorganic nutrition of
freshwater organisms, or even better, how freshwater organisms have dealt
with lower levels of available inorganic nutrients?

Question 2) Am I making a faulty assumption that these nutrients aren't
*as* available in freshwater systems as they are in marine systems?

Now, thinking back, I used to have lots of problems with dropsy and TB like
symptoms (bloating and sores). I used to feed freshwater fish a staple of
flake and bloodworms. Once I had the shop, I began dumping excess
"expensive" marine food into the freshwater fish so it wasn't wasted... When
I saw how much more vibrant the animal's color became, well, I started using
that unless I had a horribly busy day and had to just do a "drive by
feeding" with flake or pellets.

As a result of this (and I didn't realize this until just now) I *haven't*
had problems of this manner ever since. I didn't see it in the thousands of
fish that I held at the shop (which I recognize is a short term keeping), I
haven't seen it in my Rainbowfish or Loaches that I've kept since then for 3
years (thier color has *exploded* recently now that I've been feeding the
better foods), the natives are too soon to tell. However, what is
observeable so far is, these natives were in vibrant color at 76 degrees
(they look the same at 63 now). I would never had expected to see darters
in full color (the rainbow darters would seriously go full nuptial
brightness 3 times a week, redside dace were always *red sided*) at those

Okay so that's all good and nice that it's fairly simple and only marginally
more expensive to get easy fish to shine with krill, plankton, and high
grade brine, not to mention proportional growth (they're bigger, but not
fatter). What's the next step...?

3) I wonder if making this type of nutrition available to suckers and such
would help in the causes of keeping them more healthy in our aquaria? And
I'm also thinking they're all water soluable, could it hurt to have an
overabundance of these inorganic nutrients?

Wether they're predatory or not, a hogsucker, as an example, is getting
algae and phyto as they route thru the sand and gravel looking for
invertebrate prey. Maybe this is something we've overlooked? And I wonder
how receptive they are to eating nori on a stick, which would give them a
nice shot of what they may need once a day. Nori is that green algae stuff
that you get your sushi wrapped in. If this turns your stomach (it turns my
stomach, yumyum! :), you can go to an asian market, stay at the counter, and
just ask for it. It comes in nicely packaged, unassumptive sheets :)

At any rate, it's cheap and I think I'm going to run over to the market
today to see if the stonerollers will much on it. In my marine experiences,
it was *amazing* to see that even *obligate piscavores* would eat the nori
from a clip or roll. I don't know why it never occurred to me that it *may*
be a great supplement to freshwater organisms.

Things to think about I guess.

And thus ends my lunch time rant for January 21st, 2003. :)


----- Original Message -----
From: "Bruce Stallsmith" <>
To: <>
Sent: Monday, January 20, 2003 4:40 PM
Subject: Re: NANFA-- do fish get goiters?

> Yeah, the equivalent structure in fishes to a thyroid is in the midventral
> gill area. If you look at so-called "primitive" chordates like Amphioxus
> the agnathans like lampreys, they have a structure called an endostyle
> developed into the thyroid in tetrapods like us.
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