# Something odd I noticed tonight



## steel1212 (Feb 21, 2006)

I was looking at my plants with the night lights on, for some reason these night lights are white not blue. Anyways, my ludwigia cuba, ludwigia grandulosa, ludwigia repens, and my limnophila aromatica was doing something I hadn't seen before. The tops of the plants where closed up. It looked like they where closeing up for the night. By closeing I mean the leaves went straight up and together. Are they reaching for the night lights or are they actually closeing?


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## freydo (Jan 7, 2006)

i think they're closing, as i've some of plants doing the same thing and i don't have night lights. most plants and flowers do that in the wild, or so they say on the nature shows that i occassionally watch


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## GekkoGeck0 (Nov 3, 2005)

My L. sessiliflora closes up its top leaves shortly before I turn the lights off.

I think it's a good indicator of when it's had enough light. Flowers close up for the night in the wild, and I assume that the plant stops photosynthesis when it closes up.


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## Zapins (Jul 28, 2004)

Yep, got it correct guys. Aquatic plants (and other plants) do tend to close their leaves at night. I believe it is for protection, since the plant is much less likely to get damaged if it minimizes the volume it takes up by closing the leaves/petals etc... then keeping them open longer then they have to be.


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## BryceM (Nov 6, 2005)

This is easier to see in some species than others. It's pretty obvious that plants have a natural daily rhythm. Randomly turning lights on an off at different times every day probably isn't the best thing. I'm wondering if this would be even more pronounced if our tanks had a gradual increase and decrease in intensity similar to sunrise & sunset. Reef people really go nuts with this, simulating phases of the moon and all sorts of things.


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## HeyPK (Jan 23, 2004)

These movemets are called nastic movements, and this is a subset of nastic movements called photonasty--- a non-oriented movement in response to change in light levels. Actually, if the plants have been on a regular schedule of light and dark, they start closing up before the lights turn off, and so they are not responding to a change in light level, but are responding to their internal clock.


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