Dear Lisa:
That was very astute of you to "candle" the newborns using back lighting, and the differences you observed may be helpful in culling out the fry.
As you know, special precautions must be taken to circumvent the surface-hugging behavior of pelagic fry like your Sunbursts and the problems this presents, and above all, to prevent them from accidentally ingesting air. The planktonic seahorse fry feed at the surface where their prey tends to congregate, drawn to the light, and all too often the newborns take in air along with their food and cannot expel this air. When this happens, it upsets the fry’s equilibrium, and they will float sideways on the surface of the water. Upon close examination of these floaters, a bubble of trapped air can be spotted just below the head (Tracy Warland, pers. com.).
So if that is what you are observing when you shine a light through your nursery from behind, Lisa — a bubble of trapped air situated just below the head in the neck or uppermost part of the chest, those may indeed be newborns that have accidentally ingested air, and if they are having any buoyancy problems as a result, it would be a good idea to weed them out since their long-term prospects are very poor.
If you are unsure, retain the newborns for further rearing until buoyancy problems become apparent and then cull out any floaters that emerge during the pelagic phase of their development.
It is perfectly normal for the male and female to attempt to re-mate shortly after the male delivers his latest brood, but it sounds like your stallion was simply too exhausted after his exertions to rise to the occasion. Delivering a large brood is very strenuous and always takes a lot out of a male, but they usually muster up the strength to complete the copulatory rise and get pregnant again within a day or so of giving birth. It’s a good thing that your female dropped her clutch of eggs, because once they hydrate or "ripen" the ova, they must either deposit them with a receptive male within 24 hours or discard them in order to avoid becoming egg bound, and egg binding is almost always fatal. She won’t ripen another clutch of eggs until the next breeding cycle, so your male will have about a month to recuperate before they mate again.
Hopefully, he will have recovered from the rigors of childbirth overnight, and resumed eating again in the morning. He needs to build up his strength again after his recent labors.
Best of luck with your first attempt at rearing, Lisa!
Happy Trails!
Pete Giwojna
Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.
