|
When I was surfing through your site I noticed the ‘Extra ordinary organism found in a vivarium’ page. To me the description of the organism and the pictures pointed in the direction of a fungi: the fast growth, the little ‘balls’ at the end of the yellow branches (I think this is where the spores are formed). So I did some research in our library here at the Vrije Universiteit and (of course!) the internet. I came up with the following option: I think it is a so-called ‘slime-mould’. More specifically, it could be a Physarum polycephalum. However, this is only a guess. It is very difficult to find the exact species from a picture. A microscope and a fungus classification guide are needed! Too bad it died, but this is probably because the temperature outside the vivarium was too low for the fungus to survive.
Just type in the name ‘physarum’ in google and you’ll get enough hits. I added a couple of pictures to this mail which look pretty much like the ‘extra ordinary organism’.
Here is also a short description of fungi in general and a description of slime molds:
Fungi
Fungi are the great decomposers and recyclers of nature. Their hair-like filaments invade dead plant matter, and are sometimes parasitic on tree roots. Just about every square centimetre of rainforest soil has fungi filaments. By breaking down organic material so plants can re-use the nutrients, fungi help rainforests to grow on very poor soil. It is the fruiting body (reproductive organs) of fungi that we know as mushrooms, toadstools, bracket fungi and puff-balls. Rainforest fungi may have dazzling colours and bizarre shapes. Slugs, snails, cassowaries, rat kangaroos and insects feed on fungi but many brightly coloured species are poisonous to people and other animals.
Fungi are a very visible part of bushland scenery, particularly in wet seasons. They are ecologically vital in all communities. They were previously classified as the fifth kingdom, but now this has been split up into two or three kingdoms. They are characterised by two different types of cells – tubular (hyphal) or elliptical (yeast) cells. They do not photosynthesise, but have an external digestion method. Fungi are heterotrophic (they do not produce their own energy like plants) and obtain energy from complex food, like dead or living plants and animal tissue. They are able to reproduce by producing spores. (Most mushrooms only live long enough to distribute their load of spores). The fruiting bodies of many fungi have delicate gills through which these spores are discharged. They do not have a flowering stage.
There is a very vast range of fungi, with more biodiversity than in the plant kingdom, and possibly more than in the animal kingdom. Most fungi are closely associated with dead or living plants, and sometimes with animals. They show a wide range of interactions with other organisms from mutualisms to pathogenicity.
 |
Slime Moulds
Slime moulds belong to the subdivision Plasmodiogymnomycotina II, and the class Myxomycetes.
Originally, the slime moulds perplexed biologists, as they did not seem to completely fit the classification of either animals or plants, but they shared some characteristics of both groups.
In structure and physiology they have an animal-like plasmodium (an acellular, creeping somatic phase of the slime mould), but their reproductive structures are fungus-like, producing spores covered by definite cell walls in stationary sporophores.
They were classed as animals by DeBary (1887), a founder of the science of mycology, and called Mycetozoan. From the Greek language, this translates as mushroom/fungus animal.
The term was later changed to Myxomycetes (slime mushroom/fungi).
Because they are a relatively old and stable group, they have become specialised in several ways. They departed sufficiently from the main evolutionary line of fungi to constitute a subdivision of their own.
Slime moulds usually live in cool, shady, moist places in the woods, on decaying logs, dead leaves, or other organic matter that holds abundant moisture. There are some species that occur in open spaces, creeping over vegetation, and these are particularly conspicuous on the grass of city lawns. Other species may develop on plant debris, animal droppings and pieces of bark taken from living trees and placed in a moist chamber for a few days.
The most important factors governing the distribution and abundance of slime moulds are probably moisture and temperature. Not all species may be found at all times in the year.
The majority of the 450 or so known species are universally distributed, but there are some confined to temperate regions, tropics, or alpine areas.
In general, slime moulds are of little direct economic importance. They feed on bacteria, protozoa and other minute organisms.
The slime mould Physarum, common in North America, is used extensively as a research tool in the McArdle Laboratory for Cancer Research, University of Wisconsin.
Good luck with your projects and I will definitely stop by in the near future
to check out your business.
Martijn Niessen
Vrije Universiteit
Faculty of Human Movement Sciences
Amsterdam
The Netherlands
|
