Mermaids and sirens are rather finicky creatures, they tend to prefer the beauty of femininity, for it traditionally attracted more sailors to their watery dooms.

However that leads to a shortage of merMEN to really.. procreate the species.
So how else did you expect mermaids and their kin to gain more numbers~?
how fortunate for them that many critters now love to swim and explore the depths, male and female alike~ Numbers are certainly booming thanks to modern technology~!

for  Kathrya