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Re: [APD] Aquatic-Plants Digest, Vol 53, Issue 17

I find this experiment very interesting and I applaud your efforts.
There are those here with a lot more experience in plant biology than
me, so I'll just tell you what I know about that plant.

Ceratopteris was my first aquarium plant I ever grew when I set up my
first aquarium.  My experience with it was that it grew like a
beautiful weed for 2 weeks and then drained the water column
completely and died.  The plant can either be grown planted or free

The most common form is thalictroides but my store sold some unknown
Tropica variety.

One last thing.  This particular plant is an East Asian plant in case
you didn't know.

> Hi ... I've been helping my middle-school neighbor with his science
> project. He's testing the effects of different fertilizers and
> pesticides on aquatic plants.
> He has 7 jars set up with Water Sprite, under 2x 40W T-12 fluorescent
> lights for 12 hours/day. We picked out 7 plants similar in size/age
> for the project. (There were hardly any plantlets on the leaves --
> these were relatively young and very healthy plants, about 7-8" long.
> I've been growing water sprite for many years and have become
> familiar with their growth characteristics in aquariums. Most
> plantlets develop on mature leaves, and as the plantlets grow, the
> parent leaf deteriorates.)
> The experiment is still in progress, and will end on Jan. 31st. One
> plant serves as a control. The other jars get small daily doses of
> the following: nitrate, phosphate, Tide w/Downy laundry detergent,
> malathion, pyrethrin, and a pesticide. As an added bonus, the plants
> had lots of pond snail eggs so he is also able to observe the effect
> of these substances on the newly-hatched snails.
> It's currently two weeks into the experiment; the control, nitrate,
> phosphate, and pesticide plants seem to be OK. The main leaves have
> grown a bit larger, which is normal growth. The malathion plant was
> first to succumb. However, we're seeing something interesting in the
> plants dosed with Tide and pyrethrins.
> For the Tide plant, mature leaves have all turned brown. However,
> there's been a profusion of plantlets sprouting from the brown adult
> leaves. Those plantlets are starting to show patches of brown, and
> will probably be dead in a few days.
> For the pyrethrin plant, the mature leaves are still green but there
> are many plantlets sprouting from them -- not as many as the Tide
> plant, but still, a surprisingly large number of plantlets compared
> to the control plant.
> I've been googl'ing around trying to understand the unusual growth in
> these two cases, but it's hard to understand what's going on because
> I don't have a background in botany and chemistry. I'm hoping that
> more knowledgeable people on the list can shed some light on what's
> going on.
> Tide case: we know that the detergent has "enzymes" for getting rid
> of stains, including grass stains. So I'm assuming that these enzymes
> are attacking the mature leaves, causing them to turn brown. But
> what's causing so many plantlets to pop out? Is it caused by a
> chemical trigger in the detergent? Could it be that there's a built-
> in chemical trigger in stressed parent leaves to create plantlets
> before they turn brown and die?
> Pyrethrin case: this compound is extracted from chrysanthemum
> flowers. Pyrethroids are the synthetic version of that natural
> compound. They destroy bugs by messing with their nervous system.
> (http://npic.orst.edu/factsheets/pyrethrins.pdf ) There's also
> concern about the compound's effect on aquatic animals like fish and
> crustaceans (http://www.sciencenews.org/articles/20060204/bob9.asp).
> According to an abstract at http://www.pubmedcentral.nih.gov/
> articlerender.fcgi?artid=1566380, pyrethroids are hormone disruptors.
> Although the paper is about its effect on breast cancer cells, I'm
> wondering if there's a similar mechanism in pyrethrin/pyrethroids
> pushing the plant's asexual reproduction into overdrive?
> If anyone has additional information, names of scientists we could
> contact for more information, and/or references that could help us
> understand the results of the exposures to TIde and pyrethrin, please
> post or email me at whimbrel at comcast dot net.
> thanks!
>    shireen
> Shireen Gonzaga
> Baltimore, MD
> whimbrel at comcast dot net
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