Maureen Sorry. My original argument was going to be “I could carry a fertilized chicken egg in my armpit until it hatched (the egg, not my armpit). This would not make me the mother.” But, that would have left me open to the valid counterargument “In nature, no species intentionally takes and incubates the eggs of another.” I wanted to use an example about a species of clam, but I couldn’t find my Gould book naming the species of clam or remember if it passed the fertilized eggs or immature larvae onto the gills of fish.
AFAIK, the seahorse eggs would develop just as well in any place that was the proper temperature and provided oxygenated water. The male’s pouch just provides a convenient storage space and nothing more. I do contend the embryo must develop into a form capable of survival in the environment (breathing air or water as appropriate, the ability to digest food) within the body of the egg producer for it to be defined as birth.
Considering that AFAIK seahorses do not produce milk, they are not mammals.
