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Antagonistic coiling

Posted by mbmceach on 03 May 2007 at 00:13 GMT

Just wondering if the authors, or anyone else out there, has any thoughts on why antagonistic genital coiling would be beneficial (from the female perspective). Makes sense that a female would want to exclude some males from parenting her offspring, but certainly not all of them. Yet from my reading of the paper, the antagonistic coiling seems to be a universal thing?

Also, on a related note... how much is known about variation in morphology within a single species, and since males can basically regrow their phalluses each year (they regress during the non-breeding season), is there a potential for individual males to alter their genital morphology over their lifetime?

RE: Antagonistic coiling

pbrennan10 replied to mbmceach on 14 May 2007 at 15:22 GMT

Our best hypothesis for the antagonistic coiling is that is useful for females to discriminate against males who attempt forced copulations. We believe that when the female mates with her chosen male (not a froced copulator), she may be able to help the copulation be successful, by altering her behavior. Because the oviduct is soft tissue whe may be able to do this. For example she can cease struggling, or she can actively position herself to allow her partner to bypass the vaginal barriers. We would like to test this idea, but as you can imagine it is difficult to "look inside" the female to know exactly what is happening during copulation.
We know nothing about the intraspecific variation of male phalluses. The question is very interesting. How much of the morphology is condition dependent? We are just beginning to look at this.