WAR  of  the  MICROWORLDS  

How do I kill Thee?   Let me count the Ways!   (#32)  click here for full list                 

Haptospora appendiculata:  Conidia of this endoparasite of bdelloid rotifers have a doughnut-shaped modification at the base (see SEM soon!).   This structure functions to assist the spore in lodging in the mastax of the host.   Note: ALL  rotifers have a mastax between the oesophagous and the gut.  The   mastax is a distinctive structure usually composed of  four horny pieces. The two lateral ones crush food against the two central ones (= incus) during ingestion of food.   For more information on this fungus see Barron, G.L. 1991. Can. J. Bot. 69: 503-506.

Diagram: (left) shows reproductive structures of fungus {conidiophores, conidiogenous cells (phialides), and conidia (phialospores)}, bursting out through the epidermis of the dead encysted host.  In the micrograph (right) you can see the membranous collarettes at the mouth of the phialides.

Left: micrograph shows horny mastax of a bdelloid rotifer.  Middle: circular white dots are where the conidia of Haptospora  have attached to the mastax.    Right: conidia have germinated inside the mastax and the assimilative hyphae are now growing into the soft body tissues of the host.