male/females

Dear hobbyist:

I’m glad to hear your Mustangs are doing so well. Keep up the good work! A pair of Sunbursts would make wonderful tankmates for your Mustangs.

Many hobbyists share your concerns about breeding. It’s such a common question that I devoted a section of my new book (Complete Guide to Greater Seahorses in the Aquarium, TFH Publications, unpublished) to that very topic:

To Breed or Not to Breed? That is the question…

Many seahorse keepers are unable to provide the time and effort rearing requires, particularly since a breeding pair often produces a new brood of babies (hundreds of fry) every month. When they find themselves in that situation, some hobbyists choose to prevent their seahorses from breeding by segregating the sexes and keeping males and females in separate tanks, or by ordering seahorses that are all the same gender.

Others allow their seahorses to breed, which gives the aquarist a chance to observe their amazing courtship displays and mating rituals, as well the miraculous spectacle of the male seahorse giving birth, but sacrifice the newborn fry by allowing hungry tankmates (compatible fishes and inverts, such as cleaner shrimp or scooter blennies, not the other seahorses) to make a meal of them. It sounds heartless and cruel, I know, but that’s precisely the fate most seahorse fry suffer in the ocean. At very best, only one or two seahorses from each brood survive to maturity in the wild; the rest are lost to predators.

Most people feel the parents are much happier in the aquarium if allowed to pair off and mate, so when aquarists are too busy or inexperienced for rearing fry, most hobbyists simply let nature take its course and eliminate the newborns as forage for bigger fish.

In my opinion, the deciding factor is that we now have considerable evidence that segregating the sexes can actually be harmful to the health of Hippocampus. The Cape seahorse (Hippocampus capensis) is a prolific breeder that produces well-developed benthic fry that are fairly easy to raise. So much so, in fact, that experienced breeders sometimes find themselves overwhelmed by a population explosion of capensis. When this happened at the London Zoo, the curators decided to resort to enforced abstinence as a means of population control (Bull and Mitchell, 2002, p 30). They achieved this goal by isolating their adult capensis in same-sex groups. However, they soon began to notice serious stress-related problems with this arrangement (Bull and Mitchell, 2002, p 30). There was an increase in disease outbreaks and heightened aggression among their groups of males (Bull and Mitchell, 2002, p 30). The isolated females developed swollen abdomens and experienced difficulty with egg binding (Bull and Mitchell, 2002, p 30). Respiration rates increased and there was noticeably more twitching among the segregated seahorses (Bull and Mitchell, 2002, p 30). As a result, the Zoo soon stopped separating their males and females. They are now allowed to court and breed freely and the resulting offspring are simply left in the main tank with their parents and allowed to fend for themselves (Bull and Mitchell, 2002, p 30). Some of the exceptionally hardy capensis fry manage to make it on their own and reach adulthood without any special care at all (Bull and Mitchell, 2002, p 30).

In many cases, I feel that’s the best solution for the home aquarist as well, both for the seahorses and their keepers. The seahorses certainly enjoy a richer, more natural life when they have the opportunity to interact, court one another, pair up and reproduce. And the hobbyist has a chance to observe social interactions and behaviors he would otherwise never see, such as competition for mates and daily greetings and birthing, including one of the grandest spectacles in all of nature — the colorful courtship and mating ritual of the seahorse!

Over a period of days, the partners perform a series of ritualized maneuvers and distinct displays — brightening, reciprocal quivering, pumping, pointing, and several delightful dancelike displays (the carousel dance, Maypole dance, and the parallel promenade) — all culminating in the copulatory rise and exchange of eggs. Once a pair has bonded, these maneuvers are repeated regularly in a daily greeting ritual that strengthens and reinforces the pair bond. In my opinion, the seahorses have a better quality of life when they are allowed to engage in these activities in the aquarium, even if it means sacrificing their young.

Some hobbyists have a friend or neighbor or know a fish guy from the local pet shop who are interested in rearing, and allow them to take home their seahorse fry and raise them. Some hobbyists even ship the fry to breeders elsewhere who are set up for rearing. Those are other possibilities the overburdened home hobbyist can explore.

Allowing the seahorses to breed freely leaves the door open for aquarist to try his hand at rearing someday when he’s better prepared and equal to the task. Once the hobbyist gains a little more experience and confidence keeping seahorses, there will likely come a time when the aquarist feels he’s ready for the challenge of rearing. Sooner or later, most seahorse keepers decide to try their hand at rearing. This way, when that day arrives, a breeding pair of ponies will already be at hand, ready to give their owner plenty of fry to raise.

Those are my thoughts regarding segregating the sexes kizurt2k5. No one will fault you if you go that route and, in that event, I would suggest you stick with females. There is much less chance that there will be any aggression or tension between members of the fairer sex and mares are protected from sex-related health problems such as pouch gas and some forms of gas bubble disease, such as recurring pouch emphysema.

Best wishes with all of your fishes!

Happy Trails!
Pete Giwojna

Dear hobbyist:

You’re very welcome! I think you’ll really enjoy a mated pair — the courtship and mating dances are a spectacle to behold. And even if you just give the babies away, watching a pregnant male give birth is something you’ll never forget.

The gestation period in the genus Hippocampus lasts anywhere from 10 days to 6 weeks depending on the species and the water temperature (Vincent, 1990). The volume of the pouch increases dramatically as the pregnancy progresses. A male that is carrying a significant number of young becomes very rotund so that only a very thin layer of epithelium and connective tissue separates the interior of the pouch from the outside world by the time birth is imminent (Vincent, 1990).

The fully developed young emerge from their individual compartments and shake loose into the lumen of the pouch prior to birth (Vincent, 1990). They become very active toward the end of the pregnancy and can sometimes be seen wriggling about through the membrane of the swollen brood pouch. This appears to be every bit as uncomfortable as it sounds, since expecting males become agitated and distressed as the big moment approaches. They experience definite labor pains when birth is imminent, evident as a series of powerful contractions, and soon begin pumping in time with these birth spasms in order to forcibly eject the fry from their pouches. Labor usually begins well after dark in the early morning hours (Vincent, 1990). The distraught male may pump and thrust vigorously for hours before finally ejecting the first of the newborns (Vincent, 1990). The fry are expelled singly or in ones and twos at first, but are soon spewing forth in bunches and bursts of a half dozen or more.

Delivering a large brood this way is hard work, and the exhausted male will pause periodically to recover from his exertions, gathering his strength until he is caught in the throes of another round of contractions. In some cases, it takes 2-3 days for the entire brood to be delivered in this manner.

No matter how often I see a male giving birth, it never ceases to amaze me. Watching the fry erupt into existence that way is an incredible sight. They are perfect miniature replicas of their parents, able to fend for themselves from the first. It seems a brutal beginning, a ruthlessly rude awakening, to be violently thrust into the world in such an abrupt fashion, but the newborns hit the water swimming without missing a stroke. It’s a thrill to be witnessing such a miracle of nature and always leaves me awed and exhilarated!

Enjoy your seahorses!

Happy Trails!
Pete Giwojna