Conidial Appendages Research Articles

Trichomycetes inhabiting the digestive tract of Simulium equinum larvae

Both the mid and hind guts of Simulium equinum L. larvae, collected from a stream in Dorset, are shown to contain several species of Trichomycetes. Thalli attached to the peritrophic membrane lining the mid gut belong to Harpella melusinae Leger & Duboscq, whilst those attached to the hind gut are Paramoebidiutn chattonii Duboscq, Leger & Tuzet, unidentified species of Smittium , and two morphologically distinct species of Stipella . Thalli of H. melusinae occur in their vegetative and asexual reproductive forms, zygospore production not having been observed. Smittium thalli are epiphytic upon P. chattonii , are characterized by a unique form of branching, the distal regions of which often bear appendaged conidia, and on one thallus a conjugation between adjacent hyphae resulted in the formation of an anvil-shaped zygospore. The two morphologically distinct species of Stipella differ mainly in the foim of the holdfast and in the shape and arrangement of the conidial appendages. They both occur in vegetative, asexual and sexual reproductive conditions, with the conidia-bearing thalli restricted to the posterior region of the hind gut and zygospore-bearing thalli to the anterior region.