Thanks for the update! It’s great to hear that installing a protein skimmer and increasing the aeration and surface agitation in your aquarium has resolved the problem with the huffing. That’s a pretty good indication that the dissolved oxygen levels are back up where they should be, easing the breathing of your seahorses accordingly. Well done!
In the first picture you posted a day or so ago, it was obvious that your Hippocampus reidi stallion was in breeding condition. As you know, sir, during the breeding season, the male’s brood pouch undergoes elaborate changes to prepare it for pregnancy. Often called the marsupium, this remarkable organ is much more than a simple sack or protective pocket or a mere incubator for the eggs. Think of it as an external womb, which undergoes placenta-like changes throughout the pregnancy in order to meet the needs of the fetal fry. Its internal architecture is surprisingly complex. In fact, the male must begin preparing his pouch to receive his next brood long before gestation begins (Vincent, 1990). The elaboration of the internal pouch anatomy that is necessary to support the developing young is triggered by the male hormone testosterone. The four layers of tissue that comprise the pouch undergo increased vascularization at this time (Vincent, 1990) and a longitudinal wall of tissue or septum grows up the middle of the pouch, separating it into left and right halves. This increases the surface area in which fertilized eggs can implant, and enriches the blood supply to the lining of the pouch in which they will imbed. Just before mating occurs, this is enhanced by a surge in the active proliferation of the epithelial tissue that forms the innermost layer of the pouch (Vincent, 1990).
In the offseason, the levels of gonadotropin, testosterone and adrenal corticoids in the bloodstream are reduced, and the pouch deflates and shrinks accordingly, reversing these placenta-like changes. In that first picture of your stallion, it was clear that his pouch was not deflated in shrunken, but rather had undergone some of those changes discussed above in preparation for breeding. However, the enlargement of his pouch could merely indicate that your reidi are getting serious about courtship and breeding now, so their hormones are flowing and he is preparing his pouch for eggs. It doesn’t necessarily mean that your male has already mated successfully, just that he is ready to breed.
After looking at the additional pictures you posted today, and getting a look at his brood pouch from a number of different angles, he does have the appearance of a gravid male that is carrying developing young early in his pregnancy. If his pouch remains distended or enlarges further over the next couple of days, and the stallion has no buoyancy problems (i.e., he can swim and feed normally without fighting the tendency to float), then it’s probably safe to conclude that there was a successful mating and transfer of the eggs.
If you contact me off list ([email protected]), I will be happy to provide you with lots of information on breeding and rearing this species so that you can begin preparing a suitable nursery tank. The Brazilian seahorse (H. reidi) is a tremendously prolific species, but the young are quite challenging to raise due to the the enormous numbers of fry that are produced (broods of up to 1600 newborns have been reported for these prolific ponies) and the prolonged pelagic phase of development they undergo. There are a few things you can do to improve the survivorship of the young and increase your chances of raising some of the babies, and I will be happy to explain some of the tricks of the trade for you if you are interested, sir.
I cannot positively identify the small black seahorse from the photographs. It has a superficial resemblance to H. erectus, but its high, crownlike coronet with very well-developed tines is more similar to H. barbouri or H. procerus, it has sharper, longer spines and than we normally see on erectus, and it lacks the distinctive lined pattern that is so typical of H. erectus. Without being able to do meristic counts and key it out, I am not able to make a definitive identification, but he’s a very handsome pony regardless of his actual species.
All my thanks for sharing the photographs with the group, Nova! The seahorses certainly appear healthy and that was a beautiful firefish (Nemateleotris magnifica) in the earlier photo you posted as well.
Best wishes with all your fishes (and invertebrates), sir! Here’s hoping your H. reidi stallion presents you with a fine healthy brood of young within the next two weeks.