While drinking from the water fountain at the gym tonight, me and my friend were reminiscing about the classic disney channel movie "The thirteenth year" about the boy who turns into a merman.
This, of course, got us on to the question of how mermaids and mermen reproduce. the biology of it isn't obvious, so we were stumped. What IS obvious is that this is a question for google.
Wikipedia (of course) had the answer:
The Mermaid problem is an observation occasionally mentioned in literature, concerning the difficulty of having sexual intercourse with a mermaid. Although mermaids are commonly depicted as beautiful, variably nude, and enticing, a man attempting to have sex with one would be thwarted by the typical portrayal of the creature: a fish from the waist down, with no vagina. Some fiction, aware of the long running question, deliberately avoids the question for humorous effect. More generally, it can also be a joking reference to the unusual sexual interest many non-human characters seem to have with humans in fantasy or science fiction, and potential physical issues therein.
Theoretically a mermaid would reproduce as most aquatic animals do, by external fertilization, requiring a human male to deposit his seed underwater onto her eggs. (The confusion is further compounded by the fact that mermaids are usually depicted with a navel and breasts, which would suggest placental vivipary rather than ovipary.) However, this situation is sometimes rectified by portraying mermaids as having genitalia more similar to dolphins than fish, or having the ability to change into human form, e.g. the fishtail splitting into two legs when it dries, and again turning into fishtail when the legs touch with water. A prominent example of this is the Touchstone Pictures film Splash where the Mermaid character Madison, portrayed by Daryl Hannah, transforms into human form and sustains a romantic and sexual relationship with Allen Bauer, portrayed by Tom Hanks, while retaining many of her undersea habits and mannerisms.
A French idiom, finir en queue de poisson (to end with the tail of a fish), makes reference to this difficulty; it refers to a promising start that ends in disappointment. It originates from a line in Horace's Ars Poetica: Desinit in piscem mulier formosa superne (the beautiful woman ends in a fish's tail).
Interestingly this was not always an issue. In the past it was not uncommon for a mermaid (actually a medieval siren or melusine) to be portrayed as having a split tail, with a vagina located (or merely implied to be) between the two parts.
H. P. Lovecraft's short story "Dagon" and the logo of the American coffee chain Starbucks are examples of this.
well, gosh, who knew the starbuck's logo had the answer all this time!
Just goes to show ya we need to open our eyes :)