CONSUMER-DECOMPOSER
PROTISTS (SLIME MOULDS)
They possess the characters of both animals and fungi.
Slime Moulds
Slime moulds are saprophytic protists. Anton De Bary
(1887) related them to animals and called them as
Mycetozoa. These are also named as fungus animals
because they share the common characters of both animals
and fungi and are known as protistian fungi, due to their
protistian nature. The general features of slime moulds are
discussed here
(i) They are found in moist terrestrial places rich in
decaying organic food.
(ii) The body of slime moulds is covered with mucilage
having gelatinous consistency. That is why they are
called slime moulds.
(iii) The vegetative parts lack cell wall. They are
surrounded by plasma membrane. However, the
spores have the cellulosic cell walls.
(iv) Locomotion in slime moulds mainly occurs with the
help of pseudopodia. They generally move towards
moisture and avoid light.
(v) They show phagotropic or saprotrophic nutrition;
they do not have chlorophyll.
(vi) Both sexual and asexual modes of reproduction occur.
(vii) They are like Protozoa in their amoeboid plasmodial
stage and similar to true fungi in spore formation.
(viii) The cellular slime moulds occur in all humus-
containing upper layer of damp soil. When the food
supply is short or conditions are not favourable the
amoeboid cells form aggregate without any fusion.
This aggregated mass is called pseudoplasmodium.
The examples of cellular slime moulds are
dictyostelium and polysphordylium.
(ix) Acellular slime moulds (plasmodial slime moulds)
are commonly found on dead and decaying plant
matter. Plasmodium is the free-living thalloid body of
the acellular slime moulds. It is wall-less mass of
multinucleate protoplasm covered by slime layer.
During unfavourable conditions, the Plasmodium
differentiates and forms fruiting bodies bearing
spores at their tips. During favourable conditions,
Plasmodium can spread over several feet.
the
(x) Slime moulds are beneficial as they cause
decomposition of organic matter in the soil.