Helmut:

Have had 3 Cypraea tigris that I have gotten through dealers here in NM
over the years.  You want:

1) Oxygenated water, so your pump with oxygen should do.  A more stable
environment would be a "natural" reef-type system (layered substrate which
will support dinitrification from ammonia all the way to nitrogen gas) or
an artificial system with dinitrification since you do not want the
nitrates to build up - deadly to most invertebrates.  Living at 5000 ft in
Albuquerque limits my access to fresh seawater so I do everything
artificially - that is why I have created an "artificial" reef system in my
tank.  Another small submersible water pump in th system will keep the
water moving so you do not have any  areas of low oxygen in the system.

2) Cypraea tigris, as has been mentioned loves algae.  Since I try to
suppress algae growth with my living corals in my tank, I but dehydrated
compressed algae (red, brown and green) and he loves it all (pet store).

3) Need adequately support of Ca/Sr so he can make new shell (most of mine
were not full-grown when I got them) material and keep up the beautiful
luster.  Putting just quartz peebles will not do this.  Either you need to
artificially add Ca/Sr to the system, change the "fresh" seawater often, or
the easiest is to get a substrate of crushed aragonitic sand on the bottom
(with your seawater above) and it will "buffer" the Ca and Sr
concentrations in the seawater to the correct concentrations for the
Cypraea.  DO NOT USE CALCITE OR CRUSHED ROCK FROM ANY GEOLOGIC FORMATION,
THE CONCENTRATIONS OF CA AND SR WILL BE TOO LOW - GO TO YOUR LOCAL PET
STORE!!!

4)  Not sure what else you have in the tank, might have to make some
adjustments.

5)  Keep at 72 - 78 degrees F.  Use a heater is necessary.  Careful with
the heater, put it along a wall and not in a corner.  Lost a 3 year old
when he got caught between the heater and the corner when the heater came
on - fried cypraea!!!  Not very smart creatures.

Paul

P.S.  Write off line if you need more info.

At 02:48 AM 5/1/00 -0400, you wrote:
>Dear Conchlers,
>
>maybe once I will have an aquarium with living Cypraeas, sometimes to get
tigris in our pets shop. What is
>the minimum they need, how large should be the tank for 2  tigris. Are
they difficult to keep. What do they
>need: corals, stones, eg for crawling around. What do they eat. Could
anybody give me some informations.
>thanks in advance
>Helmut from Innsbruck
>
>Helmut "Helix" Nisters
>Franz-Fischer-Str. 46
>A-6020 Innsbruck / Austria / Innsbruck
>phone and fax: 0043 / 512 / 57 32 14
>
>e-mail: [log in to unmask]
>web:    www.netwing.at/nisters/
>           (please visit it and sign guestbook)
>
>office:
>Natural History Department of the
>Tiroler Landesmuseum Ferdinandeum Innsbruck
>Feldstrasse 11 a
>A-6020 Innsbruck / Austria / Europe
>phone: 0043 / 512 / 58 72 86 - 37
>
>