Sand trout

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Robert O. Dahl

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Oct 20, 1996, 3:00:00 AM10/20/96
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While walking in a desert wash the other day. I ran across a dead specimen
of the sand trout (Salmo dessicata.) It was the first one I'd seen in many
years. For those of you from outside the Southwest, our native desert
sand trout has developed an ingenious method of surviving in an
environment where streambeds are dry most of the year. The fish emerges
from beneath the sand during flashfloods and feeds on detritus and insects
caught and carried by the water. When the waters recede, the clever sand
trout buries itself in places where the wet sand has settled with a
quicksand-like consistancy, and secretes a mucus material that completely
surrounds it, similar to the survival strategy the spadefoot toad. This
mucus layer dries and hardens, forming a watertight seal in which the fish
is encapsulated. When the next flooding occurs, the capsule dissolves and
the trout swims once more. Their method of reproduction is even more
fascinating, but I will save that for another time.

Cheers,

Robert

--
Robert O. Dahl
ot...@azstarnet.com
rd...@bio2.edu (work)
http://www.azstarnet.com/~ottar

David Sewell

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Oct 20, 1996, 3:00:00 AM10/20/96
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In article <ottar-20109...@news.azstarnet.com>,

Robert O. Dahl <ot...@azstarnet.com> wrote:
>While walking in a desert wash the other day. I ran across a dead specimen
>of the sand trout (Salmo dessicata.) It was the first one I'd seen in many
>years. For those of you from outside the Southwest, our native desert
>sand trout has developed an ingenious method of surviving in an
>environment where streambeds are dry most of the year. The fish emerges
>from beneath the sand during flashfloods and feeds on detritus and insects
>caught and carried by the water. [...]

Robert, what you're calling a "sand trout" here is actually the fish
usually known by the common name "flood trout" (Salmo torrentis)
because, as you correctly note, they are usually seen soon after the
peak of flash floods when they feed and mate. Most of the remaining
population has retreated south along the Santa Cruz to where the
water flows more regularly, since they require a minimum of something
like a month of water and around Tucson they don't get that any
more.

Salmo dessicata is the species that evolved to produce silicon-like
secretions that actually allow it to glide or "swim" through dry sand,
with most of its body just below the surface and only the dorsal
fin visible. In the old days its main predator was the roadrunner,
since roadrunners would streak along the washes and snatch the fins
to pull the fish up. The sand trout, in turn, had developed a
keen sensitivity to vibration and could often dive several inches
to elude the roadrunner.

Their numbers were severely diminished in the 19th century by horseback
travel in the washes--they'd dive to elude the first one, but often
be crushed by a following horse when they surfaced for air (sand
trout gills can't operate more than two inches below the surface--
too much sand pressure). And motorized traffic has driven them to
near extinction, not so much from being run over, as from exhaustion
and energy depletion in areas where the constant rumble of cars
continually triggers their diving reflex. (The only ones I've ever
seen were in washes way up in the foothills, away from roads.)

--
David Sewell * ds...@packrat.aml.arizona.edu | "Where the earth is dry, the
Dep't of Geosciences, Univ. of Arizona | soul is wisest and best."
WWW: http://packrat.aml.arizona.edu/~dsew/ | --Heraclitus

David Sewell

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Oct 21, 1996, 3:00:00 AM10/21/96
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In article <ottar-20109...@news.azstarnet.com>,
Robert O. Dahl <ot...@azstarnet.com> wrote:
>While walking in a desert wash the other day. I ran across a dead specimen
>of the sand trout (Salmo dessicata.) It was the first one I'd seen in many
>years. For those of you from outside the Southwest, our native desert
>sand trout has developed an ingenious method of surviving in an
>environment where streambeds are dry most of the year. The fish emerges
>from beneath the sand during flashfloods and feeds on detritus and insects
>caught and carried by the water. [...]

Robert, what you're calling a "sand trout" here is actually the fish
usually known by the common name "flood trout" (Salmo torrentis)
because, as you correctly note, they are usually seen soon after the
peak of flash floods when they feed and mate. Most of the remaining
population has retreated south along the Santa Cruz to where the
water flows more regularly, since they require a minimum of something
like a month of water and around Tucson they don't get that any
more.

Salmo dessicata is the species that evolved to produce silicone-like

David Wright

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Oct 21, 1996, 3:00:00 AM10/21/96
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ds...@packrat.aml.arizona.edu (David Sewell) wrote:


>Salmo dessicata is the species that evolved to produce silicon-like


>secretions that actually allow it to glide or "swim" through dry sand,
>with most of its body just below the surface and only the dorsal
>fin visible. In the old days its main predator was the roadrunner,
>since roadrunners would streak along the washes and snatch the fins
>to pull the fish up. The sand trout, in turn, had developed a
>keen sensitivity to vibration and could often dive several inches
>to elude the roadrunner.

<snip>

> (The only ones I've ever
>seen were in washes way up in the foothills, away from roads.)

I was a graduate student in zoology at the U of A in the early '60s. I
often did field work with a friend who worked on the behavior of
pallid bats, Antrozous pallidus. These bats begin flying just before
total darkness and they fly in arroyos where they feed on low-flying
insects. Sometimes they land to grab an insect.

One evening we were stretched out at the edge of an arroyo and saw a
pallid bat land and immediately start to wave its wings to try to
escape something. It was dragged under the sand. When we got to the
bottom, we found that a sand trout had grabbed it and pulled it under,
and that the sand trout had curled its tail to secure its purchase.
While we were in the arroyo, another trout jumped up and grabbed an
insect and made a distinctive plop as it hit the sand. There must have
been a school of them in that arroyo because I heard the plopping that
night till I fell asleep in my sleeping bag.

David


Jim Peavler

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Oct 21, 1996, 3:00:00 AM10/21/96
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David Sewell correctly identified the Salmo dessicata:
*****

Salmo dessicata is the species that evolved to produce silicon-like
secretions that actually allow it to glide or "swim" through dry sand,
with most of its body just below the surface and only the dorsal
fin visible. In the old days its main predator was the roadrunner,
since roadrunners would streak along the washes and snatch the fins
to pull the fish up. The sand trout, in turn, had developed a
keen sensitivity to vibration and could often dive several inches
to elude the roadrunner.
*******

He is correct that this amazing fish has become quite rare. There are
still small schools of them in some of the arroyos that lie to the
west of and drain into the Rio Puerco of New Mexico. Many people are
surprised that they are found at this high an elevation.

They can be caught on live bait, if you are very careful. A small
whiptail or skink is usually pretty good bait, but you must use a
slack line (not too slack, or the trout will hit your skink and turn
it loose before you can set the hook). If your line inhibits the
movement of the live bait even a little, the salmo dessicata dives.

This manner of fishing is quite difficult, so naturally many of us
members of the Fly Fishers Federation have been working on a
hand-tied lure that will work. So far we have not succeeded. If any of
you out there have developed a pattern with which you have had any
success, we would love to hear about it.

Jim Peavler
VIVA New Mexico!
http://www.viva.com/nm/

Robert O. Dahl

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Oct 21, 1996, 3:00:00 AM10/21/96
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My sincere thanks to Dave Sewell, David Wright and Jim Peavier for sharing
their own personal observations on both the sand AND flood trout. It is
only relatively recently through an internet newsgroup such as this that
such a number of disparate observations of a shy and rare creature could
be collected in very short order. I had considered myself privy to what I
thought was extremely esoteric knowledge until you gentlemen pulled the
rug out from under my smugness and provided witness to the fact that these
shy species have been more widely observed than I had ever imagined.

I am humbled by your knowledge,

RO

Marcos J Montes

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Oct 22, 1996, 3:00:00 AM10/22/96
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Jim Peavler wrote:
>
> They can be caught on live bait, if you are very careful. A small
> whiptail or skink is usually pretty good bait, but you must use a
> slack line (not too slack, or the trout will hit your skink and turn
> it loose before you can set the hook). If your line inhibits the
> movement of the live bait even a little, the salmo dessicata dives.
>
> This manner of fishing is quite difficult, so naturally many of us
> members of the Fly Fishers Federation have been working on a hand-tied
> lure that will work. So far we have not succeeded. If any of you out
> there have developed a pattern with which you have had any success, we
> would love to hear about it.
>
> Jim Peavler
> VIVA New Mexico!
> http://www.viva.com/nm/


Surely this fish must be on the endagered species list?

I am truly impressed by the knowledge of the members of this NG on
this obscure subject. I thought I was somewhat familiar with the
denizens
of the southwest (lived in Las Cruces for 22 yrs), but I have never
heard of sand trout, or read any information whatsoever about these
animals.

Is there some particular source of information about these animals that
can be found in libraries, etc?

Marcos

--
Treat the earth well; it was not given to us by |Dr. Marcos Montes
our parents: it was loaned to by our children.
|mon...@neptune.nrl.navy.mil
-Kenyan Proverb
|mar...@mensch.stanford.edu
~~~~~~~~~~~~~~~~~~~|URL: http://cssa.stanford.edu/~marcos
|~~~~~~~~~~~~~~~~~~~~

Robert O. Dahl

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Oct 25, 1996, 3:00:00 AM10/25/96
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> Jim Peavler wrote:
> >
> > They can be caught on live bait, if you are very careful. A small
> > whiptail or skink is usually pretty good bait, but you must use a
> > slack line (not too slack, or the trout will hit your skink and turn
> > it loose before you can set the hook). If your line inhibits the
> > movement of the live bait even a little, the salmo dessicata dives.
> >
> > This manner of fishing is quite difficult, so naturally many of us
> > members of the Fly Fishers Federation have been working on a hand-tied
> > lure that will work. So far we have not succeeded. If any of you out
> > there have developed a pattern with which you have had any success, we
> > would love to hear about it.
> >
> > Jim Peavler
> > VIVA New Mexico!
> > http://www.viva.com/nm/
>
>

Jim,

Herter's catalog had a sure-fire pattern at one time, As I recall it was "
Herter's go-deeper, extra-action sand runt spook" The body was tied from
genuine wild-caught Eastern Madagasgarian Lemur chest hair with a wart
hog hackle.

Robert

hol...@nmt.edu

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Oct 26, 1996, 3:00:00 AM10/26/96
to

A small endangered fish, the silvery minnow, has been a thorn in the sides
of farmers here in the Rio Grande Valley who sometimes suck the river
dry to irrigate crops. Some local "experts" here have claimed that the fish
is able to burrow into the mud and quiescently survive until the rains come,
like the spadefoot toad. Wildlife biologists say otherwise.


David Sewell

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Oct 26, 1996, 3:00:00 AM10/26/96
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In article <326D0635...@nrl.navy.mil>,

Marcos J Montes <marcos...@nrl.navy.mil> wrote:
>Surely this fish must be on the endagered species list?
>
>I am truly impressed by the knowledge of the members of this NG on
>this obscure subject. I thought I was somewhat familiar with the
>denizens
>of the southwest (lived in Las Cruces for 22 yrs), but I have never
>heard of sand trout, or read any information whatsoever about these
>animals.
>
>Is there some particular source of information about these animals that
>can be found in libraries, etc?

I'm not certain, but you might try:

AUTHOR Meine, Franklin Julius, 1896-1968.
TITLE Tall tales of the Southwest;
SERIES Americana deserta.
PUBLISHER New York, A.A. Knopf, 1930.

Dr. James M. Peavler

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Oct 29, 1996, 3:00:00 AM10/29/96
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>Herter's catalog had a sure-fire pattern at one time, As I recall it was "
>Herter's go-deeper, extra-action sand runt spook" The body was tied from
>genuine wild-caught Eastern Madagasgarian Lemur chest hair with a wart
>hog hackle.
>
>Robert

Wow! That sounds like it ought to do it! Do you happen to know of it was
weighted, or was it a surface lure? I still have some wart-hog necks I used
for tying lures for the basalt bass of central Idaho.


Jim Peavler
Scientific Computing Consulting
Computer Sciences Corporation
Phillips Laboratory

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