Mating behavior in both my SH tanks!

Dear Carrie:

Congratulations on all the flirting and courting going on among your seahorses! That’s always a fun time for the seahorse keeper, since the courtship displays and mating rituals can last for several days prior to copulation and are absolutely fascinating to observe.

When dwarf seahorse stallions perform their vigorous pouch displays (Pumping And/or Ballooning) during which they inflate their pouches with water to the fullest extent and prance around all puffed up in order to impress the females, you might easily mistake their distended pouch for a pregnancy that is well advanced. But when a pair is getting serious about mating, they will also engage in displays of reciprocal quivering, so keep an eye out for that as an indicator that a budding romance will soon result in copulation, Carrie.

For instance, here’s how it Joann Heuter describes courtship and mating and Hippocampus zosterae:

"Mating in the wild takes place from around May to August, and this is also when
the most mating occurs in the tank. In fact the males are almost always pregnant
during these months. Sometimes the males will blow up their pouches with water
and go around showing the females that he has no eggs… The
mating begins with a male and female side by side their tails touching, one will
start to quiver from head to tail, then the other will do the same. This can go on
from 1 to 3 days until the female places her eggs into the males pouch. It takes
from 10 to 20 days from this point for the babies to emerge from the father’s pouch.
They come out 1 at a time over a few hour period. The male will be ready to except
more eggs within 3 to 4 days after giving birth. There is no parental care after the
babies are born."

And here’s an excerpt from Alisa Abbott’s book (Complete Guide to Dwarf Seahorses in the Aquarium) that discusses courtship and mating:

<Open quote>
Along with the dramatics of color changing, courting seahorses typically sidle together, swim side-by-side holding tails (parallel promenade), and grasp the same strand of sea grass with their tails and prance around it in perfect unison, performing a graceful maneuver often called the Maypole or Carousel dance. But there are two dramatic displays that play an essentially important role in the mating ritual of dwarf seahorses — the energetic pouch displays of the males and an amazing quivering dance-like display both partners perform together.

The dance moves demonstrated by the dwarves are fantastic and even more energetic than their giant cousins; they are like little disco infernos. The dance begins with the partners perched together, side by side, tails touching, facing the same direction and quite romantic. Then one of them will begin to tremble until its entire body is vibrating rapidly side-to-side, with its tail anchoring firmly in place. It looks almost as if the seahorse is shuddering with passion or having a seizure. After a few seconds the seahorse will stop quivering, while the other resumes the quavering dance, and the exchanges of trembling are traded back and forth for several minutes at a time.

For obvious reasons, this courtship display is known as "reciprocal quivering," and it’s an incredible sight to behold! The dwarf seahorse’s dueling dance moves would put a hula dancer to shame, and Elvis the Pelvis, the King himself, would wind up in traction if he tried to keep up. However, it’s an important part of pair formation and leads up to the next phase of courtship, which is the equally interesting pouch display of the male.

This mating stage is called "pumping" because the male inflates his pouch like a balloon and jackknifes his body with a rapid pumping motion that forces water in and out of the brood pouch. With his pouch swollen to the bursting point, the male carries out a series of vigorous pelvic thrusts that are very similar to the contractions he goes through when giving birth. This flushing action is believed to cleanse the pouch and prepare it for a new batch of eggs as well as to release special chemicals called pheromones that stimulate the females. The hormone prolactin is probably the most important of these chemical triggers. Amazing isn’t it?

One thing I’ve noticed about dwarf seahorses is that courtship often seems contagious in captivity. One couple will begin courting, then a nearby pair will start flirting and other seahorses in the vicinity will follow their lead, and before you know it, pretty much the whole herd will be dancing and displaying. It’s as though a chain reaction of courtship spreads throughout the colony, and pheromones – equine aphrodisiacs — may be the reason why. Perhaps that helps explain why dwarf seahorses breed better in sizeable groups – the more males pumping away at any given time, the more of these excitatory chemicals that are released in the tank.

Courtship’s typically last anywhere from 1 to 3 days, but eventually, the females respond to the pouch displays of their partners with a maneuver known as pointing. They stretch upwards on the tips of their fully extended tails and tilt their heads back as though pointing to the surface, signaling their urgency to rise for the exchange of the eggs. By this time, they will have ripened their eggs (possibly triggered to do so by the hormone prolactin), and the courtship will soon come to its climax – the mating itself.

Mating takes place when the partners push up from the bottom together for the copulatory rise. They bump bellies at the apex of their rise, and then the female inserts her ovipositor into the aperture of the male’s pouch, at this point, she then transfers the eggs as the couple drifts slowly downwards again.

Unlike many of the greater seahorses, which have monogamous mating systems and form lasting pair bonds, the dwarf ponies are relentlessly polygamous. Their love life usually consists of a series of one-night stands…

… the moment the last egg is deposited safely inside his incubator pouch, the slot like opening at the top of the pouch is sealed shut and the eggs are fertilized within. The brood pouch is very rich in blood vessels and placenta-like changes begin almost at once. The tissues lining the pouch expand like a sponge as the capillaries and blood vessels swell and multiply, forming a separate compartment around each egg that implants. For the next 10-14 days, the brood pouch enfolds, nourishes, oxygenates, and protects the developing embryos in a perfect temperature-controlled environment.

Just as the male seahorse undergoes a true pregnancy, he also experiences the pains of an actual labor. Gestation lasts 10-14 days, depending on temperature and diet, and as their time draws near, males often become lethargic and secretive. Their pouch will be greatly swollen, making swimming difficult, and they tend to perch in an out-of-the-way spot and stay put for long periods of time.

Shortly before birth, however, the fry begin to writhe about and shake loose from the tissue lining the pouch. Having a mass of wriggling babies in your belly is evidently as uncomfortably as it sounds, and at this point; the male often begins to swim to-and-fro in an agitated manner, signaling its distress by changing color. Often they darken themselves, but sometimes they become much lighter than normal, assuming an unnatural pallor. Periodically, they will pause to anchor themselves to a hitching post in order to execute a series of pelvic thrusts. This is the same sort of scrunching up and jackknifing the seahorses performs when pumping during courtship and it causes the mouth of his pouch, which had been tightly sealed, to gape open. It looks as though he is doubling up in agony from cramps, but the male is actually trying his best to expel his young. As he struggles to give birth, gut-wrenching spasms wrack his body. Following one such series of contractions, a tail will finally emerge from the aperture of the pouch. After a few more pelvic thrusts out pops the first baby. At first glance, they look like a bit of knotted thread, but they quickly gather themselves and swim off, miniature replicas of their parents. It’s an amazing sight to see them erupting into existence like that, one by one.

The newborns are fully independent and able to look after themselves. No parental care is provided. Fortunately, with the dwarf seahorses their fry are born benthic, which means that they are able to go towards the bottom of the tank and hitch right away. This is the main reason why hobbyists are more successful with breeding dwarfs than their larger cousins. Most giant seahorses typically have fry that are pelagic, which means that they are unable to hitch and are often seen towards the top of the tank just floating along.

A typical brood size for the dwarf seahorse can be anywhere from three to about thirty-five fry, with their average in the aquarium being about twenty. Their giant cousins can deliver upwards of several hundred plus fry. <Close quote>

So keep a close eye on your Pixies when they are dancing and watch for those telltale courtship displays of reciprocal quivering and energetic pouch "Pumping" that indicate they are getting serious about mating and the copulatory rise is near.

There is also an excellent discussion of breeding problems in Alisa’s dwarf seahorse book, so check that out if you don’t see any babies soon. The heart of their breeding season is March through August and mating sometimes tapers off during the winter months even in the aquarium.

Best of luck with your amorous ponies, Carrie! Here’s hoping you have plenty of prolific pairs that produce a plethora of perky progeny for you soon!

Happy Trails!
Pete Giwojna