Nematophagous fungus

Nematophagous fungi are a special group of carnivorous fungi that specialize in nematodes as prey. There are about 160 known species.

Demarcation and fishing organs

A distinction is made between predatory fungi and endoparasitic nematophagous. Predatory and endoparasitic fungi share some characteristics with each other, which make a taxonomic delimitation of each other and make sometimes even impossible ( in the genus Nematoctonus for example, in which both find ways of life ).

Be understood in the literature unanimously solely those species as predators that have special fishing organs of external hyphae. These fishing organs are in about 80 % of all cases sticky traps (eg Zoophagus insidans ), at the Klebfäden also occasionally rotifers can catch and 20% catch rings, such as in the type Zoophagus tentaclum. Here are formed from hyphae small loops in which, for example, can get caught nematodes. The snares can be contractile, runs through touch stimuli the sling to prevent escape of prey. They can be distinguished more finely:

• Sticky traps

• Simple sticky Fanghyphen
• Sticky Fanghyphenfortsätze
• Sticky nets
• Sticky fishing knots

• Catch rings

• Contractile catch rings
• Nichtkontraktile catch rings

Rare species have also two different types of cases, such as candida or Dactylaria Arthrobotrys botryospora.

The method of fishing by catch rings is evolutionarily quite old as the discovery of a - not more closely related to the modern species - 100 million years old nematophagous fungus in a piece of amber made ​​clear.

Predatory fungi ( predators )

Predatory fungi are active nematodes catching fungi with special fishing devices, either glue traps, where the prey sticks, or ring traps in which hang when crawling through the nematodes. After catching the fungus grows into the nematodes and decomposes gradually move it out by enzymes from the inside; the released nutrients are absorbed.

Due to the frequent occurrence in nitrogen-poor soils, it is likely that as with most carnivorous plants caught the prey is less for the recovery of metabolic energy, but more to balance the nitrogen budget.

Also the Ink Cap ( Coprinus comatus ) - a mushroom stand - can catch and digest nematodes. It forms small spherical structures with thorny excrescences. By this he exudes a toxin, which makes nematodes immobile. The nematodes are eventually colonized by mycelium of the Schopftintlings and digested within a few days.

Endoparasitic nematophagous

Nematophagous endoparasitic nematodes not catch, but grow from spores on stage in the nematode zoom and digest these gradually from within. Infected be the Nematodes of ingestion of the spores or spores that attach themselves to the outside nematodes and later grow into the worm. Another way of infection is found in the genus Haptoglossa: this obligate parasite spores whose plasma content is shot with a nematode in the future host on contact. Once the spores germinate, they form a hyphal network in nematodes, which later became the cuticle breaks and forms conidia spores as a new carrier. In the decomposed nematodes themselves may also form resting spores.

System

The majority of predatory fungi in this sense belongs to the order Moniliales in the class of deuteromycetes, a few can be found, however, also in the family of Zoopagaceae ( Zygomycetes ) and the stand fungi ( Basidiomycetes ).

Use in crop protection

Because of their effectiveness nematophagous fungi to be used in plant protection against plant pathogenic nematodes, the applications are however still in the trial (eg, Paecilomyces ).

Evidence

• Asmus Dowe: Predatory fungi and other fungal nematode enemies, A. Ziemsen Verlag, Wittenberg, 1987, ISBN 3740300426