Dear Grant:
Yes, sir — you identified your seahorse as a female in your initial post, and the seahorse in the photograph shows no hint of a pouch whatsoever. Either the pony is a female or it is a juvenile that has not yet reached sexual maturity.
Yikes, Grant — if your nano reef is a 12-gallon aquarium, that’s going to be problematic for anything but the tiniest seahorses. As we have discussed many times on this forum, unless you will be keeping one of the miniature breeds of farm-raised seahorses, such as Hippocampus zosterae, H. breviceps, or H. tuberculatus, it’s best to start with the largest aquarium you can reasonably afford and maintain (the taller, the better). In general, a tank of at least 40 gallons (150 L) is preferable if you’re an inexperienced aquarist since that’s the size when one begins to see significant benefits in terms of the greater stability a larger volume of water can provide. An aquarium of 40-gallons or more will be more resistant to overcrowding and to rapid fluctuations in temperature, pH, and salinity than smaller setups. The larger the aquarium the larger the margin for error it offers the aquarist and the greater the benefits it provides in terms of stability.
It is equally desirable to select an aquarium at least 20-inches high when keeping the greater seahorses. They need the vertical swimming space to perform their complex mating ritual and successfully complete the egg transfer, which is accomplished while the pair is rising through the water column or drifting slowly downwards from the apex of their rise. If the aquarium is too shallow, eggs will be spilled during the transfer from the female to the male’s brood pouch, and mating becomes increasingly difficult or impossible below a certain minimum depth. A tall aquarium can also help protect the seahorses from depth-related health problems such as bloated pouch and certain forms of Gas Bubble Syndrome.
Under the circumstances, you should not consider adding any Hippocampus erectus to your 12-gallon mini reef. It’s too small to sustain any of the larger breeds of seahorses long-term, and its lack of water depth will leave them predisposed to gas bubble syndrome, which is a fatal condition if left untreated. Adding so much as one more seahorse to the tank would be inadvisable, and your fancy female may be at risk in a tank that size as it is.
It’s unlikely that your seahorses will be able to reproduce in a 12-gallon tank because it is probably too shallow for any of the larger seahorse species to complete the copulatory rise. The shallower the tank, the more difficult coitus is to achieve and the more likely it becomes that eggs will be spilled during the transfer. Eventually this reaches the point where entire clutches are being lost, which is when most pairs cease trying and no longer attempt to breed.
Worse still, shallow tanks increase the danger that an overripe female may become egg bound. In a tank with inadequate water depth, a courting female that has hydrated her clutch may be unable to make the egg transfer, yet she will be reluctant to dump the eggs while a receptive male is still standing by eager to receive them. If she is retains her clutch too long, hoping to pull off the tricky egg transfer despite the lack of depth, she may become egg bound. Her lower abdomen will become very swollen and prolapsed tissue may protrude through the vent as the pressure builds up. If she is unable to release the eggs at this point and relieve the pressure, death will result. An egg-bound female is thus a very serious complication of depth limitations (Leslie Leddo, pers. com.). So you should reconsider trying to find a mate for your female.
The smallest aquarium that would be suitable for a single pair of Hippocampus erectus would be a 20 gallon Extra-High All-Glass Aquarium (20"L x 10"W x 24"H), and a somewhat larger aquarium would really be preferable. If you’re using a 24-gallon Biocube, you could consider keeping a pair of seahorses. But it would be better to stick with invertebrates for your 12-gallon Biocube and then to upgrade to a larger aquarium if you would like to set up a seahorse tank, sir.
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.
