Endless Forms in my Pond

This little snail obviously has a niche in my pond, but I didn't know they made them so small. I have seen others about 10mm in length but have no idea if they are all the same species.This little fellow was found in the pond water in a glass with the duck weed growing in it. There are also many other small animals darting back and forth,too fast to study them. The picture below is taken from its underside

Endless Forms Most Beautiful

The Creationism/Evolution argument goes on and on.. It seems to intensify as the evidence of evolution consolidates and so the creationists become more vicious. I started off my blog with the statement that Evolution is a fact and not just a theory so I was pleasantly surprised when I read in a new book just out in 2005, and a paperback 2006 sent to me by Amazon .com. They suggested I buy it and being a sucker sent off my hard earned money. It will be a while before I get through it, as reading is interrupted by naps in front of the fire in the evenings. The book is 'Endless Forms Most Beautiful': The New Science of Evo Devo and the Making of the Animal Kingdom
by Sean B. Carroll.

The paragraph that caught my attention was "The discovery of the ancient genetic tool kit is irrefutable evidence of the descent and modification of animals,including humans,from a simple common ancestor" However if you want others opinions look here as well as here

Sean B . Corroll is professor of genetics at the University of Wisconsin-Madison.


If you want to read more on Darwin and Evolution this is a good site

The Water fern and Duck weed association

Kingdom: Plantae
Division: Pteridophyta
Class: Pteridopsida
Order: Marsileales
Family: Azollaceae
Genus: Azolla
Species: A.filiconoides





Kingdom: Plantae
Division:Magnoliophyta
Class: Liliopsida
Order: Alismatales
Family: Araceae
Genus: Lemna
Spcies: L.minor

The Azola water fern and duck weed Lemna minor are in no way related as can be seen above. L. minor is related to the arum lilly and the water fern to the tree fern so how far apart could they be.However they have both solved their problems the same way and often live in close association, so much so that they both seem to share the same species of mycorrhiza. It appears to be an Ectomycorrhiza association with a mantel hypha sheath, a Hartig net and external hypha.I have not been able to discover any reference to the micorrhiza in any of the numerous descriptions of duck weed on the internet.None of the drawings or photos of roots show mycorrhiza.

Micorrhizas perform the task of making phosphate available to plants but it has been discovered that in fact in L. minor the roots
do not take up nutrients at all. Roots are for keeping the plant upright in the water, and by entwining with other roots as the top photo shows and keep the plants together to form a mat on the surface of the water.The nutrients are taken in through the bottom side of the leaflets. Whether this holds for the water fern as well I do not know.

L.minor is very widespread through many countries and is very invasive but not necessarily always a problem.

Another curious thing is that there are structures attached to the roots like long root hairs,these are shown in the bottom photo.