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John
25th January 2008, 00:51
Unisexual is a term used to describe a species in which individuals exhibit the characteristics of only sex, for example males or female (compare this to an animal that has both sets of reproductive characteristics, a hermaphrodite).

In the world of salamanders this word is most frequently applied to the complex of hybrid Ambystoma species, i.e. "Unisexual Ambystoma". In this context it describes the fact that all of the hybrid specimens in the complex are female, irregardless of the combination of Blue-spotted, Small-mouth, Jefferson or Eastern Tiger DNA.

Jennewt
28th January 2008, 03:04
Could there be a unisexual male species? I'm having trouble imagining this! If not, then a unisexual species could be more simply defined as a species consisting entirely of females. They reproduce by a sort of "cloning" method called parthenogenesis.

We have some parthenogenic whiptail lizards here in New Mexico. The amazing thing that I just learned is that they still have to "mate" in order to reproduce. Two females go through the typical whiptail mating rituals, with one acting the part of the male. This activity is necessary for them to produce the hormones needed to produce viable eggs. I suppose I'm digressing from the salamander context...

John
28th January 2008, 03:43
Well in a salamander context unisexual means female to the best of my knowledge but the word can mean either male or female.

Jan
6th January 2010, 19:22
Well in a salamander context unisexual means female to the best of my knowledge but the word can mean either male or female.

John and Jen
I found this reference to sterile males:
All individuals of these complexes are female (referring to the hybrid Ambystoma complexes), except for a very small percentage (~1%) which appear to be sterile males.

From: Unisexual "Hybrid" Salamander Complexes, Ambystoma spp. (http://www.ohioamphibians.com/salamanders/Unisexual_Ambystoma.html)

Should the original definition be amended to include this? Probably so.

Jan
15th January 2010, 13:24
How about this as a final definition:

Unisexual:
A term used to describe an organism in which individuals exhibit the characteristics of only one sex, for example female or male (compare this to an animal that has both sets of reproductive characteristics, a hermaphrodite). In the world of salamanders this word is most frequently applied to the "Ambystoma jeffersonianum complex" i.e., "Unisexual Ambystoma Complexes". In this context it describes the fact that all individuals of these complexes are female, except for a very small percentage (~1%) which appear to be sterile males regardless of the combination of Blue-spotted, Small-mouth, Jefferson or Eastern Tiger DNA.