No, sir, seahorses that are actively courting and breeding normally have a very good appetite. They tend to eat heartily because they need all the calories they can get at this time. It takes a lot of a females bodily resources to produce a clutch of eggs and ripen them for mating, so a nutritious diet rich in calories is required by breeding females.
Likewise, it is very energetically demanding for a male to be carrying a brood of developing young, and a gravid male needs all of carries he can get to support the fetal fry and embryonic young growing in his marsupium. So breeding pairs typically eat very well, 67, and it sounds like something is amiss if your female has lost her appetite and become lethargic.
It’s a good idea for you to tempt her to eat with some choice live foods, which will also provide your ponies with some useful behavioral enrichment since they get the thrill of the chase while stalking and hunting real live “catch-me-if-you-can” live prey. Hopefully that will perk her up again.
But I would also recommend that you increase the aeration and surface agitation in your aquarium to increase the levels of dissolved oxygen in the water, and that you perform a water change, or series of partial water changes, as soon as possible in order to improve your water quality and replenish trace elements in the tank.
Good luck, 67! Here’s hoping your female soon snaps out of it and begins eating like a horse again.
Pete Giwojna, Ocean Rider Tech Support