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Re: freshwater reefs

On Wed, 8 Sep 1999, Charley Bay wrote:

> 	A good while back there was discussion on this list
> 	of "freshwater reefs" that emphasized large species
> 	diversity.  Usually, this implies invertebrates.

As far as planted tanks are concerned we are probably already
overemphasising the diversity among plants and fish, and underemphasizing
other aspects.

In many freshwater bodies the predominant invertebrates
are insects.  I asked a few months back about maintaining insects in the
aquarium and that prompted a short discussion.  It seems that few insects
can be maintained in an entirely aquatic setting.

> 	I'm starting to get fairly serious about taxonomy of
> 	aquatic invertebrates. (I don't know what Thayer has
> 	yet, though.)  While I think it's unlikely that any
> 	freshwater tank can approach the "typical" diversity
> 	of a marine reef (we don't have the nutrient or
> 	compound suspension that allows for higher margins
> 	of life diversity as that found in marine systems), it
> 	still seems to me that you can have an awful lot of
> 	activity in a 10g tank that may or may not have fish.

Keep in mind that most freshwater environments are very closely related to
the adjacent terrestrial environment.  In the case of small water bodies
the two are not separate environments at all and if you were to count all
the species in that environment then I wouldn't be at all surprised to
find that the species diversity of the freshwater setting exceeded that of
the tropical reef.  But can you maintain that in a tank?  Do you want a
paludarium big enough to house a raccoon?  A heron?

Even without adding the terrestrial half (2/3?) of the ecosystem, the
"African Pond" tank described in "Dynamic Aquaria" had a pretty
substantial diversity.

> 	The following site on Benthic Macroinvertebrates
> 	talking about indicator species in water quality (hosted
> 	by the EPA) may be interesting to some on this list.
> http://ceisntsv.was.epa.gov/atlas/bioindicators/benthosclean.html

Benthic inverts have been used as environmental indicators for some time.
You may be able to find someone at nearby universities or elsewhere with
the state or federal agencies who has first-hand experience in the field,
and possibly even first-hand experience maintaining some of the inverts in
captivity.  In New Mexico I think the man to talk to is Rick Smartt at the
New Mexico Museum of Natural History.

> 	Of course, the primary problem is that many aquatic
> 	critters don't live their entire lifecycle in a tank, and
> 	often we don't want the adults flying around the room.
> 	A sealed paludarium may help, or we may just limit
> 	ourselves to some snails, mussels, isopods, or other
> 	critters that more-or-less stay in the tank (don't fly
> 	away).  The aquatic Sowbugs (Crustacea Isopoda)
> 	look interesting to me (and a few others with which
> 	I'm going to experiment).

And in their adult phase some of the insects will probably need a
different form of food then they did as larvae, and you may not be able to
provide that food or feel comfortable providing it.  Of course, I suppose
you could ask house guests into the room with your freshwater reef and
close the door behind them until the mosquitos, midges and flies have all
had their fill.  That would probably cut down on the number of visitors,
as well.

I visited the butterfly emporium in Westminster last winter and noticed
that they also had a display of aquatic insects.  You might contact them
for more details about maintaining aquatic insects in captivity.

>	Even though some species
> 	may be used by the EPA as an, "indicator of poorer
> 	water quality" doesn't mean they won't proliferate in
> 	our tanks (we can select for or against predators).

Probably you would need to at least start with "poor quality" indicators.
Freshwater aquariums usually are very seriously polluted when compared to
high quality aquatic environments.  If you learn well enough to maintain
that group then perhaps you could move on to more demanding communities.

> 	For the most part, I think control won't be a significant
> 	problem (as long as we achieve tank containment)
> 	because the proper fish can pretty much devastate
> 	any critters I've put in any of my tanks.  Believe it or
> 	not, I don't even think duckweed (Lemna minor) is a
> 	problem anymore.  I just have to remember to pull out
> 	my Carassius auratus before the stuff is all gone.

I take the reverse approach.  I net the duckweed out (not the fish) and
feed it to my daughter's goldfish in a different tank.

> 	Is anyone else thinking about this?

I have given it quite a bit of thought, and for some time now.  The
barrier I run into -- a taller barrier for me than the technical problems
of how to do it and what to maintain -- is a simple aesthetic problem.  I
keep planted tanks because they're beautiful.  After years of
contemplating the issues and options I decided that a reasonably accurate
freshwater reef will never be as attractive as a well maintained planted
tank.  Even a marine reef tank (IMHO) is attractive mostly because of its
novelty and pales in comparison to a well conceived and maintained aquatic

Roger Miller
In Albuquerque, with no shortage of opinions.