Mycoparasitism is a very common phenomenon
existing naturally in nature. Quite a lot of interesting
literature already exists regarding this subject [1^5].
A mycoparasite is a fungus which attacks other fungi. When grown together, it can overgrow the other
fungus, its mycelium may coil around the host mycelium, it can also show antagonism to the host fungus by secreting antibiotics [6], toxic radicals [7] or
wall lytic enzymes [8]. It can also enter the host mycelium, bringing about coagulation of the host protoplasm and ¢nally causing widespread damage to
the latter [9]. Mycoparasitism by the members of
the genus Pythiumis also well known, the most important fungi beingPythium oligandrumandPythium
acanthicum [10^13]. Pythium periplocum has also
been considered as a mycoparasite and recently, together withP. oligandrumandP. acanthicum, it was
studied on 73 species of ¢lamentous fungi and a
comparison of the mycoparasitism of the three species was made [14]. Apart from these three species of
Pythium, there are sporadic reports of mycoparasitism by other species likePythium acanthophoron[15]
andPythium radiosum[9]. All these fungi have one
common structural resemblance: their oogonial walls
are ornamented with spines. Very rarely, a fungus of
the genus Pythiumhaving smooth walled oogonia
has been reported to be a mycoparasite. One such
example is that of Pythium aphanidermatum,