One-Sided Ejaculation of Echidna Sperm Bundles
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 provide scanning electron micrographs of their morphology. Sperm bundling appears to confer increased sperm motility, which may provide the potential for sperm competition between males.
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|Item Type:||Journal Article|
|Keywords:||short, beaked echidna, ejaculation, penis, sperm, Monotremata, sperm bundles, sperm competition|
|Subjects:||Australian and New Zealand Standard Research Classification > BIOLOGICAL SCIENCES (060000) > PHYSIOLOGY (060600) > Animal Physiology - Systems (060603)|
|Divisions:||Past > QUT Faculties & Divisions > Faculty of Science and Technology|
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2007 University of Chicago Press|
|Copyright Statement:||Reproduced in accordance with the copyright policy of the publisher.|
|Deposited On:||30 Jul 2008|
|Last Modified:||29 Feb 2012 23:39|
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