Schematic diagram of characteristic zygospore morphology of Basidiobolus ranarum and Conidiobolus incongruus. Schematic diagram of characteristic zygospore morphology of Basidiobolus ranarum and Conidiobolus incongruus. (A) B. ranarum zygospores. Smooth, thick-walled zygospores are produced homothalically and demonstrate prominent conjugation beaks. These beaks represent the remnants of the conjugation tubes formed between the mating hyphal elements. (B)C. incongruus zygospore. Smooth, thick-walled zygospores are produced homothalically and may be distinguished from those produced byB. ranarum by the absence of the conjugation beaks. Julie A. Ribes et al. Clin. Microbiol. Rev. 2000; doi:10.1128/CMR.13.2.236