One‐Sided Ejaculation of Echidna Sperm Bundles

@article{Johnston2007OneSidedEO,
  title={One‐Sided Ejaculation of Echidna Sperm Bundles},
  author={Stephen D. Johnston and B Smith and Michael Pyne and Deborah J. Stenzel and William V. Holt},
  journal={The American Naturalist},
  year={2007},
  volume={170},
  pages={E162 - E164}
}
We report for the first time an unusual ejaculatory mechanism in the short‐beaked echidna in which each side of the bilaterally symmetrical, rosettelike glans penis is used alternately, with the other being shut down. This is unparalleled in mammals but is reminiscent of the use of hemipenes in squamate reptiles, providing further reproductive evidence of a sauropsidian lineage in the Monotremata. Further, we describe the occurrence of motile sperm bundles in ejaculated echidna semen and… 

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