I have an alien species that is my pet project. Now I'm to reproduction, which I have a specific idea for, I'm just not sure exactly how it works. My creatures are aquatic, and everything goes on underwater.
The female lays eggs, which are probably about the size and shape of a golfball. The male fertilizes them soon after, then coats the eggs in his saliva. These creatures then need to grow, still inside the egg, to a football shaped thing about a foot long, at which point they will emerge from their eggs. The areas these eggs are laid in are nearly stagnant pools of freshwater, such as lake bottoms, swamps, bayous, deltas, meres, or ponds. You get the idea. Probably.
These creatures are capable of producing electrical signals, using them for hunting, visualizing their surroundings, and possible for communication. So during the later egg development small aquatic creatures could potentially be lured in using electrical signals. If that helps at all.
These creatures are humanoid, and are on average about 4.5-5 feet tall. You can assume their dietary needs are about that an electric eel, only scaled up.
The main issues I see are the actual egg, which I assume would have to be some kind of membrane capable of growing. I was thinking of having the male's saliva help digest nutrients, which would then be absorbed by the membrane, feeding it and the creature within.
The question is, is this feasible from a biological standpoint? If not, how can I make it more so?