Date: Fri, 19 Feb 1999 13:02:43 +1100 From: "Ross Rowe" <firstname.lastname@example.org> To: email@example.com Message-Id: <aabcdefg501$foo@default> Subject: Re: Aldrovanda culture
I was very interested to read you culture notes. The red Aussie
forms sounds very interesting and I would be interested to learn of
a local source.
Ross Rowe Canberra Australia
>>> "Douglas W. Darnowski" <firstname.lastname@example.org> 19/02/1999
3:05:54 am >>> Regarding Aldrovanda culture, I have accidentally
found a large increase in growth when placing Japanese-form plants
in a tank with guppies, along with the usual rushes, Lemna, etc.
Whereas similarly grown plants without fish present have not
branched during the winter, these plants have grown vigorously
(increase averaged 3-5 growing points per original growing point
during 6-8 weeks). I had been hoping that the fry from the guppies
would be caught by the Aldrovanda, but the baby fish turned out to
be too large. (I have tried to raise Daphnia magna and a few other
crustaceans (using various techniques) as an appropriately-sized
prey species without great success. Any advice on that point?)
I do not yet know why this has occurred, but my first suspicion is
elevated CO2 due to respiration by the fish.
These plants are being kept at about 60F/15C night and 70F/21C day,
with 14h day/ 10h night. The fish have been well fed, so I assume
that inorganic nutrients are abundant (haven't yet tried to
measure). The plants have stopped producing large traps depite not
becoming fully dormant (or the fish have been eating the traps--I
haven't had a chance to observe this closely enough as the plants
are at home--my pay comes for working on soybean molecular and cell
biology). Perhaps increased nutrient levels are causing suppression
of carnivory, or perhaps this is partial dormancy.
The petioles are all much more robust than on leaves from plants,
and their color is lighter but not pale, as if more body color (e.g.
white flavonoid) is present. The stems seem to be less robust than
for plants cultivated otherwise.
This is anecdotal since it only concerns approx. 6 plants (Japanese
form; I am calling a single growing point not attached to another
enlarged growing point) in one tank, and I have started a similar
smaller tank for Australian red Aldrovanda. Once summer comes, I am
planning a more systematic experiment, with replicates and controls,
to determine the effect on Australian, Japanese, and Polish
Aldrovanda, to measure CO2 and nutrient levels, etc.
If this effect turns out to be consistent among the various
Aldrovanda clones in cultivation, it could be useful for increasing
material. Plants could then be returned to fish-free conditions for
resumption of trap production and carnivory.
Does anyone have similar experience with Aldrovanda and fish? Also,
is there an ichthyologist or someone who is a fish hobbyist who can
recommend a species of fish which would reproduce in captivity and
the fry of which would be of an appropriate size for Aldrovanda to
Douglas Darnowski Department of Crop Sciences 384 ERML 1201 West
Gregory Drive University of Illinois Urbana IL 61801 work ph: (217)
244-6150 fx: (217) 333-4777 home ph: (217) 356-6606 fx: (217)
356-4454 email: email@example.com
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