eed
on animals that are even smaller than they are including other nematodes.
Other free living nematodes feed on phytoplankton such as diatoms,
algae and fungi. Many terrestrial species feed on plant roots, penetrating
the cells and sucking out the contents. They are considered parasitic
in the way that fleas are parasitic on other animals, they can cause
great damage to the plants in this manner.
Species that live in sediments and other aquatic environments
ingesting particles of the substrate when they digest associated
bacteria and / or organic material.
Others feed more directly on dead organic material such as decomposing
plants and animals or dung where they may actually be eating the
bacteria or fungi that are feeding on the decomposing material
rather than being a decomposer directly.
The parasitic forms of nematodes show a great many variations
on the theme.
- Ectoparasite of plants - lives outside the plant
- Endoparasite of plants - lives and breeds inside
the plant having entered as a juvenile
- Saprophagous - juveniles and adults are free living,
juveniles enter invertebrate animal host and cause no harm,
but feed on dead tissues when the host dies.
- Zooparasitic juvenile stages only - juveniles
parasitize a host organism and then leave when it becomes
adult, the adult does not feed and may not have a
functioning gut. its job is reproduction only.
- Phytoparasitic juvenile, Zooparasitic adult - juvenile
lives as a plant parasite and is taken in by the animal host when it
feeds. The adult then parasitizes the adult and infects the
larvae of the host with juvenile worms which are then ready
to enter and parasitize the plant host again.
- Zooparasitic adult females only - young live in the
soil, males die after fertilizing females in the soil, pregnant
females then enter the animal host.
- ... and a whole range of other strategies with more than
one host to help the worms distribute themselves and complete
their life cycles
What eats nematodes?
Free living nematodes are themselves
prey for almost any predator that is larger than they are. This
will include other nematodes including those of the same species.
There is a surprising "predator"
of soil dwelling nematodes however and that is a fungus. This fungus
lays traps of rings attached to the fungal hyphae (thread-like growths).
Each ring is made of three highly specialized cells that swell up
rapidly when a nematode worm passes through them. The worm is captured
and the fungus passes hyphae into it to digest it.