Breeding Seahorses

Dear Cheryl:

I agree with you completely — the morning greeting ritual between pair bonded seahorses is indeed a fascinating display.

The brilliant colors sported by courting seahorses are often displayed during their other social interactions as well. The daily greeting ritual is a good example of this. Research indicates that once they have mated, certain species of seahorses form lasting pairs in the wild (Vincent, 1990). They spawn repeatedly and exclusively with one another (Vincent and Sadler, 1995), remaining in the same location so they can stay together. Pair-bonded males take up residence at a small home base, perhaps a square meter or so in size, within their chosen mates’ much larger territory and seldom stray from that spot thereafter (Vincent and Sadler, 1995). Researchers thus speak of these males as being “site-specific,” meaning that day after day they can be found at the same tiny patch of the vast seagrass beds (Vincent and Sadler, 1995). The female, meanwhile, roams and hunts over an area perhaps a hundred times larger, which is centered around the male’s home base (Vincent and Sadler, 1995). This arrangement allows the couple to live together and maintain daily contact without competing for food (Giwojna, Mar. 2002).

Thus, every day, shortly after dawn, pair-bonded seahorses meet at the male’s home base and perform a daily greeting ritual (Vincent and Sadler, 1995). In tropical and subtropical species, the morning greeting involves a dramatic color change followed by a brief ballet, and it is really an abbreviated version of their prolonged courtship display, only it lasts 5 to 15 minutes rather than a few days (Vincent, 1990). In the aquarium, pair-bonded seahorses will conduct daily greetings exactly like those of their wild conspecifics.

Greeting begins when the seahorses approach one another each morning at first light, adopt their vivid courtship colors, and carry out the preliminary phases of courtship (Lourie, Vincent and Hall, 1999). Brightly adorned except for their heads and mid-ventral lines, which darken (Vincent, 1990), the partners proceed with their picturesque parallel promenade and briefly conduct their familiar carousel dance, clasping their tails around a convenient perch and circling around it like merry-go-round ponies at a carnival (Giwojna, Feb. 2002).

Interestingly, it is always the female who both initiates and ends the daily greeting ritual (Vincent, 1990), by approaching the male at his home base to begin with and subsequently leaving his immediate vicinity after perhaps a quarter hour of such dancing.

Daily greetings serve to strengthen and reinforce the pair bond, but more importantly, they keep the couple acutely attuned to one another’s physiological condition, enabling them to keep their biological clocks synchronized (Vincent, 1990). When the male delivers his latest brood, the female will be waiting nearby, ready to hydrate her next clutch, and they will typically remate within the next 24 hours (Giwojna, Feb. 2002). This morning greeting ritual is probably a more important factor than mating itself in keeping the male and female together (Vincent, 1990).

So keep a close eye on this particular pair for the next day or so, Cheryl, and you may well get to see the copulatory rise and transfer of the eggs.

Best of luck with your prolific ponies, Cheryl! Try gradually reducing their water temperature and simultaneously shortening the photoperiod of your seahorse tank as this Fall, and hopefully they will take a break from breeding during the off-season.

Happy Trails!
Pete Giwojna