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Oak Leaf alternatives: Magnolia?

Posted: Mon Jul 10, 2006 12:21 pm
by YuccaPatrol
I thought I would separate this discussion from the other current discussion about oak leaves.

I just went down to my oak tree and collected a few handfuls of leaves. I have numerous other types of hardwood trees, as well as magnolia trees.

I was thinking that the leathery thick leaves of the magnolia tree might be an excellent choice as these leaves are very durable and sturdy and likely to last a long time underwater.

Does anyone know if there might be any possible toxic substances harmful to shrimp in magnolia leaves?

I found this reference of toxicity information on a variety of trees and plants indicating that Magnolia is less toxic to humans than Oak:
http://www.aragriculture.org/horticultu ... plants.htm

Of course, humans and decapods differ greatly in their physiology, but this does suggest that magnolia leaves might be a good and safe leaf for our shrimp tanks.

Note that ALL species of Oak are listed together, suggesting that the relative safety of various species is about the same, so you should be able to collect leaves from any species of oak native to your local area.

Does anyone have any experience or knowledge concerning the use of magnolia leaves with shrimp?

Posted: Mon Jul 10, 2006 3:25 pm
by Gregor Samsa Mendel
I have no experience with magnolia leaves in aquaria. However, I do know that many species of magnolia are native to moist areas of Asia and the Southeastern US, which also have many native species of decapods. In nature, magnolia leaves probably fall into waters containing shrimp and crayfish all the time. So there *should* be no problems...

Posted: Mon Jul 10, 2006 3:40 pm
by YuccaPatrol
Well, I think it is worth the experiment to try. When I set up my next tank, I will cover the bottom with Magnolia leaves. I'll go collect some now and put them in my driftwood soaking bin so they'll be ready in a couple weeks.

Posted: Mon Jul 10, 2006 3:53 pm
by Neonshrimp
Hi YuccaPatrol

Hope it works out for you. I am going to try it myself :wink:

Posted: Tue Jul 11, 2006 6:18 pm
by hoddit
I'd think the earlier poster is correct.....I'm in northwest FL and magnolias seem to be located near water quite frequently. Please update on your success with these as I think they'd be relatively appealing visually because of their shape.

Posted: Wed Aug 16, 2006 9:02 pm
by YuccaPatrol
My experimental Magnolia leaf tank has been going for 1 month now. All 6 of the juvenile/sub-adults are still alive and I observed one female carrying eggs today, as well as another with a very large yellow saddle.

We'll have to wait one more month to confirm that these shrimp will reproduce readily with Magnolia leaves, but I am very hopeful about it.

Once I have successful reproduction and some more time observing this tank, I will offer a more comprehensive report on my findings.

I have fed very little, as this tank had a LOT of algae growth before adding the magnolias. Red Ramshorn snails (and a couple MTS) spent the first 2 weeks eating all of the algae. Mostly, I just let the shrimp eat what they can find in the digested algae debris and whatever microscopic goodies are growing on the magnolia leaves.

Posted: Fri Aug 18, 2006 4:03 am
by Neonshrimp
Thanks for the update. I will try it when I set up my new tank next week :D How many did you use and what size tank did you put them in?

Posted: Fri Aug 18, 2006 1:31 pm
by YuccaPatrol
Neonshrimp,

Because I wanted to test for any toxic effects of the magnolia leaves, I added about 15 large leaves to a 10 gallon tank. There is no substrate and the leaves cover the bottom 1/3 of the tank.

If you are going to use more than 1 or 2 leaves, you may want to soak them for several weeks, as they do release a good bit of tannins if water staining is a concern.

Also, the leaves do seem to contain a good bit of residual sugars which will cause a temporary bacterial bloom on their surfaces, especially at the thick tip of the stem. This went away after about a week once the bacteria finished consuming the sugars in the leaves. No dangerous increase in ammonia, nitrite, nitrate occurred during this time.

Again, I'll give a more thorough and detailed report once I have confirmed breeding success in this tank.

Posted: Fri Sep 08, 2006 5:23 am
by YuccaPatrol
The day I have been waiting for has arrived. . . .

Last night I observed the first newly hatched shrimplets in the magnolia leaf tank. :-)

To re-cap, this tank was set up in early July with 15-20 large magnolia leaves as substrate. It had previously been used as a quarrantine tank and contained 6 neon tetras and a LOT of algae covering 3 sides of the tank. Aquaclear 50 filter with Tetra Billi sponge covering intake. Flow is set to the lowest setting and adjusted as necessary to compensate for the sponge clogging with waste.

The tetras were removed and the magnolia leaves along with 6 juvenile/sub-adult red cherry shrimp and 10 small red ramshorn snails.

Residual sugars in the magnolia leaves (particularly at the tip of the petiole (leaf stalk) caused a gelatinous, transparent white bacterial bloom on the surfaces of the leaves which lasted for less than 2 weeks before disappearing. Water conditions and shrimp behavior were unaffected by this although the bacterial bloom was not pretty to anyone but a microbiologist, it was a normal part of the cycle of decay for the leaves.

The magnolia leaves do stain the water with tannins, and the water remains slightly yellow almost 2 months after adding the magnolia leaves.

At 3 weeks all visible algae growth had been consumed, and the decaying waste was allowed to settle on the tank bottom to provide substrate and nutrients for micro-organisms.

50% water changes were done weekly, and tested weekly for pH and nitrate. pH fluctuated betwen 7.0 and 7.4, but has settled at a constant 7.2 for the past month. Nitrate has been less than 10mg/L (nearly undetectable with my home kit) over the course of this experiment. Of course, your local water conditions will vary.

Very little commercially prepared foods were added during this study, as shrimp were constantly foraging on the magnolia leaves and in the debris at the bottom of the tank. Approximately once a week, 2-3 pellets of Hikari Crab Cuisine were offered.

Compared to my experience with other setups, these shrimp seemed to grow faster and reach sexual maturity sooner than I have observed in the past. 3 berried females were observed over the past month and the first shrimplets were observed last night.

I will continue to update this thread when I have new information on the progress of the shrimplet growth.

Posted: Fri Sep 08, 2006 8:57 am
by Mustafa
Thanks for the update. :) This just confirms, once again, my "natural food is the best food for dwarf shrimp" theory.

Posted: Fri Sep 08, 2006 9:14 am
by Neonshrimp
Thanks again YuccaPatrol, I have been soaking my leaves for the past 2 weeks to help get the tannins out. I will put them in my tank soon :)

Posted: Sat Sep 09, 2006 4:53 pm
by YuccaPatrol
Even after 2 months of 50% weekly water changes, the water removed is still stained with tannins. However, I am sure this would not be so extreme if someone did not use 15-20 large leaves as I have.

Posted: Sat Sep 09, 2006 8:51 pm
by Newjohn
YuccaPatrol

It was sure nice of you to let everyone Know the upper limits of leaf density.

John

Posted: Sun Sep 10, 2006 1:36 pm
by YuccaPatrol
Thanks Newjohn. I wanted to ensure that if there was a low level of toxin in the leaves, that I'd be able to detect it by observing shrimp hardiness.

The next stage worthy of an announcement will be when the newly hatched shrimplets have matured and begin reproducing themselves. Only once I've obeserved the full life cycle take place in this tank, will I know that this is an effective alternative to what we have been doing previously with our dwarf shrimp.

Posted: Sun Sep 10, 2006 2:37 pm
by Newjohn
This Hobby, being so new.
Seems that there is alot of trial and error.

It sure helps
Having this Forum, to help spread the information, good or bad.
To fellow members.

John