Re: NANFA-- do fish get goiters?

Bruce Stallsmith (
Tue, 21 Jan 2003 13:08:33 -0500

I knew that talk of endostyles would separate those with a developmental /
vertebrate zoology background from everyone else... But, terrestrial leafy
green plants like spinach and kale contain reasonable amounts of
biologically available iodine. And both marine and freshwater phytoplankton
are (relatively) enriched in iodine, so that freshwater phytoplankters make
iodine available up through the food chain in most foodwebs. I don't have
specific numbers at hand for organic concentrations of iodine. From Wetzel's
_Limnology_, 3rd ed., there's a mention of iodine concentrations in natural
fresh waters as being 0.0018 mg/l, less even than bromine at 0.006 mg/l.
Hmm, this could result in a serious literature search...

--Bruce Stallsmith
Huntsville, AL, US of A

>From: "Todd Crail" <>
>To: <>
>Subject: Re: NANFA-- do fish get goiters?
>Date: 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
>food chain). Some/Most? pupfish are living in water holes where water
>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...
>I saw how much more vibrant the animal's color became, well, I started
>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
>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
>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
>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
>stomach, yumyum! :), you can go to an asian market, stay at the counter,
>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
>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
>be a great supplement to freshwater organisms.
>Things to think about I guess.
>And thus ends my lunch time rant for January 21st, 2003. :)
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