Sperm storage in <em>Centrobolus</em> spp. and observational evidence for egg simulation

Abstract

Sperm storage organs and their controlling mechanisms are described for Centrobolus spp. The upper reproductive tract has separate insemination duct, spermatheca and oviduct. Muscles controlling sperm movement towards the spermatheca were identified as muscles of the bursa and gutter apodematique. Sensory apparatus connected to the spermathecae were identified. The presence of a fully developed egg in the bursa of C. inscriptus immediately after mating provides evidence for the egg simulation hypothesis in Spirobolida.