WAR  of  the  MICROWORLDS  

How do I kill Thee?   Let me count the Ways!   (# 16)  click here for full list

Catenaria anguillulae:  Posteriorly uniflagellate zoospores are attracted to secretions from the body orifices (mouth, anus, vaginal orifice) of the host and encyst before penetrating into the body cavity to produce a chain of thallus segments connected by short hyphal-like connectives.    Thallus segments produce zoosporangia from which the zoopores escape through exit tubes to seek out and destroy additional hosts. CHYTRIDIOMYCOTA.

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Left IlustrationDiagram of nematodes under attack by Catenaria.  The posteriorly uniflagellate zoospores (left hand photomicrograph) are attracted by secretions from the body orifices of the host and form clusters of encysted zoospores at the mouths of these orifices (red arrows).  Germ tubes from the cysts invade the body cavity of the host.  At maturity the fungus forms an elongate thallus running the length of the body.  The thallus becomes segmented with each segment forming a resting body or a zoosporangium.   The contents of each zoosporangium (green arrow) mature to form zoospores that escape to the exterior through an exit tube that penetrates the nematode cuticle to the exterior.

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Catenaria anguillulae attacking Nematode

Inside a nematode's gut:  Micrograph shows the assimilation of the body contents of the host has taken place.  This is by means of very fine branching rhizoids (upper white arrows) that colonize and exploit the interior of the host.  Zoospores can be seen at different stages of maturation inside the zoosporangia (lower white arrow) and, at maturity, zoospores escape through exit tubes (red arrows) that are beginning to develop.