The life history and post-embryonic development of “Spirobolus” bivirgatus (Diplopoda: Spirobolida) on Aldabra, Western Indian Ocean


  • V. W. Spaull

    1. c/o ExperimentalTaxonomy Unit, Department of Zoology, British Museum (Natural History), Cromwell Road, London. Formerly at The Royal Society Aldabra Research Station
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    • *South African Sugar Association Experiment Station, P.O. Mount Edgecombe, 4300, Natal, South Africa


Spirobolus bivirgatus, recently known as Mystalides bivirgatus, passes through 15 stadia. These were differentiated by the ocular field method. Development is anamorphic from stadia I to VIII and epimorphic from stadia IX to XV. Maturity is reached in a few males in the eighth stadium but more normally it occurs in the ninth to twelfth stadium. Females are mature in the ninth to fifteenth stadium. Adult males possess fully developed gonopods as well as soft pads on the ventral surface of the tarsi. The pads are illustrated with scanning electron micrographs. Males die after breeding but females probably breed in three or more successive years. Eggs are laid during the wet season, December to April, and these reach maturity within the second or, possibly, the first year of growth. The density, distribution and food of S. bivirgatus is briefly described.