WAR of the FUNGI   in  the  MICROWORLD

FUNGI  versus  THE REST

e.g. amoebae, nematodes, tardigrades, rotifers, ciliates, copepods, bacteria, filamentous fungi, arthropods, pollen, yeasts etc

             How do I kill Thee?   Let me count the Ways!        H. I. T.  LIST(click on species names)           

" There are known knowns: there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know.   But there are also unknown unknowns -- the ones we don't know we don't know."                    DONALD RUMSFELDT    

So Donald got it right!?   There is a host of Microbial Interactions we know that we know nothing about and this section gives a hint as to the extent of our ignorance in one area.

01. Ballocephala sphaerospora attacks Tardigrades (Water Bears): spherical non motile 'conidia' adhere to the cuticle of the TARDIGRADE and penetrate to the interior. ZYGOMYCOTA.   

02. Myzocytiopsis humicola attacks nematodes: biflagellate zoospores track down a NEMATODE, encyst on the epidermis and penetrate through to the interior here they produce an elongate thallus that morphs into a chain of zoosporangia.OOMYCOTA.

03. Meria harposporioides attacks Protozoans: passive conidia of the fungus are drawn in on the current produced by ciliar action of the PROTOZAN host and   bond to the pellicle. DEUTEROMYCOTA - unknown affinities                                             .

04. Spirogyromyces vermicola is a microscopic 'tapeworm': spores of this 'fungus' are ingested by the NEMATODE host and 'hook' onto the inner lining of gut to feed on 'flow through' materials.  UNKNOWN  DIVISION.

05. Olpidium vermicola attacks eggs of nematodes: uniflagellate zoospores track down a nematode EGG, encyst on the 'shell', and penetrate to the interior.   CHYTRIDIOMYCOTA.

06. Harposporium anguillulae sharply pointed, helicoid conidia are ingested by the NEMATODE host and screw into (lodge) the muscle tissue of the   oesophagus ASCOMYCOTA (anamorphic).

07. Cochlonema verrucosum attacks Rhizopods (amoebae):  conidia-like spores of the fungus are ingested by the AMOEBA host  (phagocystosis) as potential   food and germinate inside to produce a sausage-like, helicoid thallus. ZYGOMYCOTA.

08. Dactylellina copepodii attacks larval and adult Copepods:   COPEPOD is captured by adhesion (chemical bonding) to stout, adhesive knobs prior to invasion and colonization. ASCOMYCOTA (anamorphic).

09. Hohenbuehelia / Nematoctonus: basidiospores germinate in the presence of  NEMATODES to produce hour-glass-shaped adhesive cells that capture   nematodes.  BASIDIOMYCOTA.

10. Stropharia spp:   Acanthocytes (a cluster of stiff sharply pointed cells),  produced on the vegetative hyphae of some Stropharia species, destroy   NEMATODES.    BASIDIOMYCOTA.

11. Zoophagus insidians: capture rotifers short hyphal branches, produced at intervals along the length of the hyphae, are baited with a substance attractive to    rotifers.   LORICATE ROTIFERS bond by their mouth to the tip of this lethal lollipop and are penetrated and digested.  ZYGOMYCOTA

12Amoebophilus simplex:  the fungus spore adheres to the outer membrane of the AMOEBA, penetrates to the interior forming a lobed haustorium (feeding cell), and literally sucks the life from the amoeba host. ZYGOMYCOTA

13. Dactylella passalopaga  attacks testaceous rhizopods (walled amobeae):   AMOEBAE, attempting to feed on fungal hyphae by drilling through the wall,   are captured and  colonized.   DEUTEROMYCOTA - anamorphic Ascomycota -

14. Peniophorella praetermissum and related species (formerly in Hyphoderma):  large bulbous laterals from the vegetative hyphae called stephanocysts capture and consume NEMATODES. BASIDIOMYCOTA.

15.  Helicocephalum oligosporum seeks out and destroys nematode  eggs:  large spores (40x 25 um) produces an extensive network of very fine hypae to seek out and attack NEMATODE  EGGS.   ZYGOMYCOTA.

16Catenaria anguillulae motile uniflagellate zoospores track down  a wide range of MICROFAUNA (living and dead):   Common broad spectrum parasite with a wide host range of microscopic animals attacks hosts using posteriorly uniflagellate  zoospores. CHYTRIDIOMYCOTA.

17.  Stylopage hadra: This is a  'lower' nonseptate fungus that has no specialized trapping device but captures NEMATODES directly at any point along the length of  the hyphae. ZYGOMYCOTA.

18 Triacutus subcuticularisThe fungus penetrates the outer cuticle of a BDELLOID ROTIFER by means of a sharply pointed three pronged spore and then grows between the cuticle and the hypodermis of the animal eventually filling the space and preventing further movement.  DEUTEROMYCOTA of  unknown affinities)

19. Haptoglossa mirabilis:  produces a very complex and sophisticated attack cell called the "Gun Cell".  The Haptoglossa gun cell is the most complicated  cell known in the fungi and arguably more sophisticated than the "nematocyst" of jellyfish fame. Using a harpoon-shaped projectile it blows a   hole in  the through the wall of  NEMATODE victim then shoots a microhypodermic through the hole an injects an infective sporidium into a rotifer,  nematode, or tardigrade in a  fraction of a second. OOMYCOTA???

20. Acaulopage tetraceros: is a predator of amoebae.   An AMOEBA touching the hypha of the fungus is instantly held fast.  Amoebae struggles are feeble so the victim   cannot escape.   The fungus doe not kill th amoeba  immediatly but penetrates the outer pellicle by a narrow peg then invaginates the inner membrane by narrow finger-like haustoria.   The fungus digests the contents of the amoebae until it is exhausted and  remains as an empty 'shell' attached to the hyphae of the fungus. ZYGOMYCOTA

21. Rotiferophthora  spp:   Rotifers consume fungus spores as food.  As a consequence of this predilection, a host of fungal species have evolved as parasites and predators of  BDELLOID ROTFERS  following ingestion of spores.   Amongst these are many species of Rotiferophthora that are specialized as parasites of rotifers but have evolved from a Verticillium-like ancestor.  Deuteromycota - affinities with ASCOMYCOTA.

22. Dactylellina candida (formerly in Dactylaria)  Devices to capture NEMATODES are  non-constricting rings and adhesive knobs.  Both types of device may be  detached from the parent hyphae.    The rings are detached from their slender stalks by the physical struggles of the nematode and and are carried off by the victim to act as dispersal agents before.  The cells of the detached ring remain viable, germinate,  penetrate the cuticle, and kill the prey. ASCOMYCOTA (anamorph)

23. IN PROGRESS Brachymyces megasporus The very large spores of this fungus contains sufficient reserves to produce an extensive mycelial 'network' in  the environment to seek out and attack their prey. ZYGOMYCOTA

24.  Lepista nuda In forest soils nitrogen is a major limiting factor to sucessful exploitation of the massive amounts of carbohydrates available in the form of woody debris.   Many of the forest fungi belonging to the Basidiomycota have developed a remarkable biological capability to seek out and destroy (lyse) SOIL BACTERIA, including nitrogen fixing bacteria, as a major nutrient source. BASIDIOMYCOTA

25. Lagenidium (Chlamydomyzium) oviparasiticum: Biflagellate zoospore attacks ROTIFER EGGS.  Zoospores encyst on the roifer egg penetrate through the 'shell' and feed on the contents to produce thalli inside the egg that release zoospores or produce resting spores.  OOMYCOTA

26. Drechmeria coniospora : one of the commonest and best documented  ENDOPARASITES of NEMATODES.   It is characterized by tear-drop shaped 'adhesive' conidia each with a spherical knob at the distal end.  Spores attach to passing nematodes at the knob end.   Most spores attach to the mouth region of the nematode (commonets point of contact)  but spores can attach at any point along the length of the body including the tip of the tail.         

27. Medusamyces lunulusporus: This is an uncommon endoparasite of BDELLOID ROTIFERS that has only been observed on two occasions.   We were not able to initiate a disease cycle by infecting our laboratory strain of  bdelloid rotifer with conidia from culture and considered it was probably  host specific.   At this time we have no idea how the fungus attacks a rotifer and how the disease progresses inside the host.   Its unusual fruiting structures were of  unique appearance and molecular studies will hopefully place this fungus with more confidence where it properly belongs.  In the meantime it is placed in its own genus, Medusamyces,  until such  time arrives for a better fit.( Barron and Szijarto, 1990.  Mycologia 82:132-137).

28. Rhopalomyces elegansThe spores of Rhopalomyces are very large, dark brown, and produced on a swollen vesicle at the tip of a tall stout 'conidiophore'.   The hyphae extremely fine (circa 2 microns wide).   The large spores have sufficient reserves to produce an extensive mycelial network in the environment.   Directional  hyphae seek out NEMATODE EGGS and bond to the 'shell' using a swollen appressorium.  The fungus pushes against the appressorial anchor to penetrate the egg and produce a swollen post infection bulb from which large diameter assimilative hyphae arise to fill the egg and absorb the contents.

29. Pythium caudatum :  This endoparasite of  NEMATODES produces large biflagellate zoospores that mature in external vesicles after the protoplasm is extruded from the filamentous thallus.   Zoospores are attracted to secretions from the body orifices of nematodes and encyst in clusters at these locations.  Each cyst germinates to produce  a fine hypha that passes through the orifice into the host and proliferates to produce a tightly packed thallus of narrow hyphae.  Originally described under Lagenidium this species was transferred to Pythium by Dick based on the large zoospores, the production of external vesicles and the extensive filamentous thallus inside the host.  The nature of its parasitic attack suggests that it is probably not host specific and may well have been described elsewhere on some other host.

30. Harposporium spirosporum. The serpentine conidia of this ENDOPARASITE OF ROTIFERS are acutely pointed at both ends.  Conidia are swallowed by  the host as a food source but lodge in the oesophagous before they reach the mastax of the host.   Here they germinate and fill the host with  filamentous assimilative hyphae.

31. Arthrobotrys oligospora.   Perhaps the most common and best known of the predatory (carnivorous ) fungi,   this species produces three- dimensional adhesive nets that capture nematodes by matching a lectin in the net with a carbohydrate in the cuticle of the nematode (lectin/carbohydrate bonding).

32. Haptospora appendiculata  Conidia of this endoparasite of bdelloid rotifers have a doughnut shaped modification at the base.   This structure functions to assist the spore in lodging in the mastax of the host where it germinates to produce assimilative hyphae that invade the body. 

33.  Conocybe lactea (Dunce Cap).   This common lawn fungus produces remarkably well developed secretory 'cells' on the vegetative hyphae.  The toxin produced by these cells kills nematodes BUT the dead and dying victims are never invaded by  fungus as nutrient sources.  It appears that the secretory appendages fuction as deterrant devices (antifeedents) that protect the fungus hyphae from attack by nematodes and perhaps other mucrofauna that would use them as a food source.

34. Pleurotus ostreatus (Oyster mushroom).  One of the favourite edible mushrooms of the mycophiles.  Pleurotus and other 'exotic' mushrooms are now produced commercially in huge amounts for consumption by the 'gourmets'.   In response to the presence of predators the fungus produces numerous secretory 'cells' over the surface of the vegetative hyphae.  These secrete droplets of a potent toxin that paralyses nematodes in seconds.  Nematodes are then located,  by specialized directional  hyphae of the fungus and finally invaded and consumed as a food rource.  .  It is probable that other potential predators of  Pleurotus are discouraged by this toxin.

35. Haptocillium species:   The genus Haptocillium was erected by Zare and Gams to include  Verticillium-like fungi that parasitized nematodes by adhesive conidia.   In Haptocillium species the conidia are produced from phialidic conidiogenous cells that may be in verticillate arrangement on erect conidiophores or scattered irregularly along the length of prostrate fertile hyphae (degenerated conidiophores?).  The conidia are modified at their distal end so that they attach to the cuticle of nematodes.    In most species there is no obvious morphological adaptation to aid in adhesion and the conidia do not appear particularly unusual.   In the fungus I described as Verticillium coronatum however, the conidia have a disinct morphological modification  at the distal end that perhaps aids them in attaching to the nematode cuticle.

36.  Verticillium  on HOLD  pro tem

37Syncephalis nodosa:  Many fungi attack other fungi as a way of life.  They are called mycoparasites. One of the most interesting associations of mycoparasitism is in the division Zygomycota and there are a number of species in this group that parasitize other zygomycetes.   In this example I show a species of Syncephalis (Family: Piptocephalidaceae)  attacking a species of Rhizopus (Family: Mucoraceae).

38. Zoopage speciesWhen an amoeba contacts the hypha of  Zoopage it bonds on contact.  The amoeba is held fast and rounds off immediately.   Amoebae are captured in such large numbers that the hyphae of the fungus are often obscured by their 'bodies' .  The fungus penetrates the plasma membrane of the amoeba by means of a lobed or heart-shaped haustorium.  The haustorium controls the nutrient flow from the amoeba to the fungus.

39. 

40.  Drechslerella anchonia: Haptoglossa has the most complex and sophisticated attack cell (gun cell) but the constricting ring found in Drechslerella species is the most sophisticated trapping device used by fungi to capture live prey.   Members of this group were formerly contained in Arthrobotrys, Dactylaria, Dactylella etc. over the years but based on molecular studies these CR predators are now classified in the anamorphic genus Drechslerella.