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Re: Nothos





Tim Addis wrote:

snipalot...

> & in conclusion with the input of more learned than I came to the
> conclusion, from people who have been to the habitats, that no salt has been
> measured in Notho' habitats (although it is not unlikely that trace elements
> might be detected from coastal habitats).

AFAIK, Brian Watters has reported that many Nothos are from fairly hard
water. That means fairly high tds (total dissolved solids). Osmotically,
that's about the same as salinity. [Some are from softer or highly variable
water, tho.]

>    Why do we put an alien substance into our Notho' tanks ? Is Velvet a
> problem in the wild ? I don't know.

Fish tend to be very sensitive to osmotic regulation conditions. Salt raises
tds and lowers osmotic pressure difference across the walls of gills and
skin. That in turn helps some fish ward off a host of problems, including
"velvet." Most Nothos would appear to be in this group.

>    Who first brainwashed us into keeping salt with Notho's ? I don't know
> this either. It was probably used to cure a Velvet problem !

The use of salt as a tonic or stress reducer goes back to even before when I
started keeping fish. ;-) My first experience with Nothos wasn't until the
late 50s, but we knew then to use salt for any fish that showed skin
distress or "shimmys." Nothos got it just like the Mollies and Guppies. [In
most *other* areas, tho, we didn't know diddly about keeping Killifish.]

>    I have explored the possibilities of keeping Notho's in a natural state
> (i.e. without salt) & the responses would suggest that peat is OK in hard
> water but not in soft. The fact that Wright kept them OK in soft water just
> re-enforces the need to debate the issue.

I didn't keep them in acid, unbuffered water, though. Only a few Aphyos,
Amazon fish and my wild Bettas seem to react well to those conditions. Mine
was medium soft and neutral to slighly alkaline. The tds was still probably
above 200, so no osmotic distress was likely.

>    I don't know if silver sand is in-hospitable to Oodinium cysts or not . I
> soak peat rather than boil it (& before you mention it either way makes no
> difference on the occurrance of velvet - my own personal findings) & I get a
> pH reading of 3.5 which should burn up quite a lot of bugs.

The antibacterial action is, apparently, pH independent. It works very well
at pH = 7.5. The 3.5 you mention must be in the extract or in totally
unbuffered water. Most of my Nothos would quickly turn belly up if I put
them in it. [OTOH, my Bettas, Corys and Apistos would cheerfully breed in
it.]

>   I didn't formulate this on my own - it's what I recieved from members of
> the BKA. Maybe it's not something that can be set in stone but there must be
> something in it for so many members to participate in the discussion.
>    Feeding brine shrimp in tanks containing peat could be a contributary
> factor to the start of Velvet (may be) I'm not leading anyone into a debate
> here but where does a debate start ?

There once was an aquamyth that velvet was *carried* by BS eggs. Not true,
but the improper use and high bacteria they can bring ('specially if poorly
rinsed) can create conditions for velvet to find an opening to get in, as
the fish get stressed or infected.

General Rule: All rich foods, used for conditioning, produce excess ammonia
when eaten. If the ammonia isn't used up by plants and filter or reduced by
water changes, the rich food will get blamed for everything the fish show as
distress symptoms from living in a sewer. Witness the tubifex and blackworm
mythology.

Fish gills are permanently damaged by as little as 0.1 ppm of ammonia! That
makes velvet infection truly easy. [BTW, I don't even have a test kit that
will reliably read that low a level of ammonia.]

>    'A fishroom with any turnover is bound to be exposed to Oodinium' well
> maybe but I kept a fish room going for many years Oodinium free until I
> started keeping Notho's.It's all grist to the mill.

I, too, find some fish far more likely to get velvet than others. Some of
the west African fish are moderately likely victims, too. As I recall, I
have had it hit small Fundulopanchax and Aphyos that I thought originally
come from quite soft "rainforest" waters. Salt helps them avoid infection,
too. I later found they were coastal fish and possibly no one had ever even
measured their water!

I don't think I have any species that I can be sure will not get velvet if
the water quality gets too bad. It is a sign of a deteriorating tank, quite
often. "There's no such thing as too many water changes," to quote Oleg.

> 
>    Thanks for the input Wright. I'm sure we can provoke a response here.

If this one doesn't work,Tim, I'll whip out some really outrageous stuff. [I
need to get more asbestos on my flame shield, first.]

Summarizing, I would say your evidence fits mine, but my reasoning is based
on tds and osmotic pressure. Some fish, like Amazon cichlids and tetras, or
wild Bettas, have developed very robust osmotic regulators to keep
ultra-low-tds waters from penetrating and bursting cells as it tries to
dilute their body fluids. Other species, like Nothos are not so well
protected, so we need to help them along with a little increase in tds. Salt
does this without tinkering with buffering or pH. The actual hardness is
probably quite immaterial. 

A bit of Carbonate "hardness" keeps the peat from crashing the pH. It serves
as a buffer. If you are cursed with truly soft, low tds water. Use some
baking soda instead of all salt, for Nothos, to raise both the tds and the
buffering.

Wright

-- 
Wright Huntley, Fremont CA, USA, 510 494-8679  huntleyone at home dot com

      To all gun-control advocates: Please just place a sign
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