Re: [Killietalk] At least one Notho does (sometimes) live in (partial)marine water

[Brian Watters <bwatters at shaw_ca>]

Bruce J. Turner wrote:

>
> In response to Bob Goldstein's note re nothos and marine water,
> my memory bank (the
> one in my head, composed of neurons) recalls one definite mention
> of a notho in salt
> water.  That notho is N. elongatus, which is from the area just north of
> Mombassa, Kenya.
> This quite attractive species was probably more widespread in the region
> before the
> human population impacted it, and may well have been resonsible for
> Boulenger's records
> of "F. guentheri" from the Mombassa area.  In modern times it has been
> collected at least
> three times, once by J. Leakey in the 60's (L.S.B. Leakey knew of this
> population, as did
> several other Kenyan aquarists), once subsequently by Dean Fanara
> and at least
> once by Wildekamp & colleagues.  Fanara definitely knew of a population
> living in the Mombassa
> estuary region that was collected in water that was mostly
> marine, but I can't remember if
> he collected it himself or a friend collected it for him.  He was not
> particularly surprised by
> this record, for he suspected that some habitats might be (or
> have been) close to waters
> under tidal influence.  I also remember that Dean thought that
> the fish in this population
> were marginally less elongate than other populations he knew about.
>

Bruce, just for the record, there have been many more collections of this
species than those that you list. As you say, Leakey was the first and he
was followed by Fanara, Walpole, et al., Holler (x2), Willert et al. (x2),
Arch Martin, Allan and Barbara Brown, Sadler, Fick (x4, at least), Watters
et al. (x6). And there may be more. At least 18 of these collections were in
the post-Fanara era. Incidentally, also for the record, Wildekamp has never
collected N. elongatus.

Most N. elongatus localities are somewhat inland from the immediate coastal
region and, therefore, not subject to any marine influence. Habitat water
conditions that I have measured vary from 130 ppm to 500 ppm TDS. So,
generally quite hard but not salty. I would think that it is simply
fortuitous that some habitats may be close enough to the sea to receive the
odd influx of marine water.

> More speculatively, I would guess that there would be some
> populations of N. orthonotus in
> the Zambezi estuary area that regularly come under marine
> influence.
>

Again, that is certainly possible but generally this is not the case. In
2004 we found one location of N. orthonotus where salt water influx almost
certainly was responsible for an elevated TDS value.

I do not disagree with you that some Nothos can be found in habitats that
receive the odd influx of salt water but this is not the norm and salt in
the water is certainly not a requirement for this genus in the wild.

Whether or not you add salt when maintaining these fish in captivity depends
on your water supply. I know people who have relatively soft water, do not
add salt and never have a problem with velvet. At my previous location in
Regina I had hard water and even then I had to add pickling salt (one
teaspoonful per gallon) to prevent velvet. At my new location I have VERY
soft water and all I have done is add some Seachem Equilibrium to raise the
TDS to about 200 ppm (I have NOT added any other salt as I did before) and
the fish are fine, with no sign of velvet - so far.
________________________________________
Brian Watters
6141 Parkwood Drive
Nanaimo, British Columbia V9T 6A2, Canada
Tel: (250) 760-0564
E-mail: bwatters at shaw_ca

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