Yes, if you noticed some spilled eggs at the bottom of the shipping bag, it’s quite possible that the seahorses may have attempted to mate en route and that the female Sunburst (Hippocampus erectus) may have dropped her clutch of eggs during a botched mating attempt. In the aquarium, it’s not uncommon at all for an experienced pair to spill some of the eggs when mating, and when that happens, any of their eggs that do make their way into the male’s pouch will be fertilized and develop normally. If the bulk of the eggs were spilled, the male will subsequently deliver an unusually small brood, and his brood pouch may not expand noticeably because of the small number of fetal fry and embryonic young he is carrying. Under those circumstances, the size of the pouch is not a reliable indicator of pregnancy and it can be difficult to determine whether I’m not the male is really gravid until he actually gives birth. Furthermore, the male seals the aperture of his pouch immediately after the transfer of the eggs, so if a mating attempt did occur within the shipping bag, you should not expect to see an open pouch on the male H. erectus.
If your new Sunbursts did try to mate in their shipping bag, it is all but inevitable that they would spill many eggs because there is simply not enough vertical swimming space in the shipping bags for them to mate comfortably and successfully transfer the eggs from the male to female. So it is certainly conceivable that the male Sunburst could be pregnant and carrying such a small number of developing young that his pouch will not grow appreciably as the pregnancy progresses. But I think that’s pretty unlikely — there is such a shortage of swimming space in the shipping bag that it’s hard for me to imagine that the male was able to successfully receive any of the eggs. The more shallow the water, the more difficult it is for seahorses to mate successfully, and swimming space is so limited in the shipping bag that I doubt whether they could make the tricky connection needed to deposit any of the eggs within the male’s brood pouch.
But I do think that accounts for the sunken in or concave appearance of the female Sunburst’s (H. erectus) abdomen. A female will lose up to 30% of her body weight after depositing or dropping a large clutch of eggs (Vincent, 1990). As a result, her abdominal plates or belly rings will be concave or pinched in for at least the next couple of days. No doubt that accounts for the sunken look of her belly plates, Amanda, which is normal under the circumstances and not a cause for concern. It will just take her a little while to fill out again…
In short, I think it is likely that Romeo and Juliet attempted to mating well in their shipping bags, but it is highly unlikely that Romeo was actually able to receive any of the eggs and I think it would be a long shot for him to be incubating any developing young at this time.
In fact, I think it is much more likely that your H. reidi will pair up and produce a brood of young for you in the near future. There is clearly courtship activity going on and Sunny certainly appears to be doing his best to get himself pregnant. Cher appears to be receptive to his advances and is a willing dance partner, so the chances are good that you may have some reidi babies on your hand before long.
Here’s a much condensed excerpt from my new book (Complete Guide to the Greater Seahorses in the Aquarium , unpublished) that briefly discusses the types of courtship displays you may be privileged to observe as your seahorses pair up and mate, including an explanation of how additional pair formation normally precedes and a good description of how the copulatory rise and egg transfer take place, Amanda:
Courtship & Breeding
Well-conditioned seahorses that are provided with a nutritious diet will reward the hobbyist with a healthy interest in courtship and breeding. These amazing animals reproduce more readily in the aquarium than any other marine fishes when provided with favorable conditions. For many hobbyists, one of the most alluring aspects about keeping seahorses is thus the prospect of breeding and rearing them. Males and females are easy to sex, court constantly when conditions are to their liking, and pair off following a spectacular mating ritual. Best of all, they are livebearers that produce large broods of well-developed, fully independent young. Many species will breed continuously throughout the year in captivity, and sooner or later, virtually every marine aquarist worth his or her salt aspires to keep and raise these exotic animals.
Pair formation and mating is preceded by an elaborate courtship ritual that is characterized by dramatic changes in coloration and increased activity levels that revolve around graceful dancelike displays and energetic maneuvers aptly described as "Pointing" and "Pumping" that are the prelude to mating (Vincent, 1990). While there are certainly some variations in the way seahorses court and pair off, as discussed below, the charming courtship ritual of the seahorse is remarkably similar for the different species of Hippocampus around the world. Whether they come from the Mediterranean, the Gulf of Mexico, the coastal waters of Australia, the Philippine islands or the Indonesian archipelago, the partners perform the same basic movements and the same pattern of events is repeated again and again. The complex choreography of courtship in seahorses remains consistent wherever it takes place, and the extraordinary ritual of pair formation in Hippocampus is one of the grandest spectacles in all of nature.
Researchers have identified and named seven distinct courtship displays seahorses commonly engage in when pairing off to mate (Vincent, 1990):
(2) Tilting, which leads to Reciprocal Quivering
(3) Dancing: Carouseling and the Maypole Dance
(4) Parallel Promenade (i.e., promenading)
(5) Pouch Displays: Pumping and Ballooning
(7) Copulatory Rise
Brightening, pouch displays, pointing and rising are seen universally throughout the genus Hippocampus (Vincent, 1990), but there is some variation between tropical and temperate species as well as between dwarf varieties and the larger breeds or greater seahorses. Tropical species tend to exhibit more dramatic color changes during courtship while temperate species often rely more on pouch displays. Dwarf seahorses generally do less dancing and more quivering than the larger breeds, whereas many of the greater seahorses dance their tails off but rarely ever shimmy. Courtship is relatively abbreviated in polygamous seahorses and rather protracted in species that bond strongly, often lasting for a period of 3-4 days during initial pair formation. We will discuss all of the different displays and the role they play in pair formation below. The terminology researchers use to designate these displays may be unfamiliar at first, but experienced seahorse keepers will immediately recognize the behaviors they describe.
Not every pair of courting seahorses will exhibit all of the displays listed below, but ALL seahorses will demonstrate most of these displays during courtship:
Approaching and Brightening.
This is a very basic display that is seen throughout every phase of courtship. When a seahorse that is ready to mate spots a prospective partner, it will move closer to the other seahorse while maintaining a characteristic posture and signal its intentions by changing in coloration (Vincent, 1990). It will hold its body stiffly erect and brighten up as it approaches (Vincent, 1990). If the other seahorse is uninterested, it will either move away or remain unresponsive, retaining its normal color. But if the other seahorse is receptive and is impressed by what it sees, it will allow the newcomer to move within touching distance and indicate its interest by brightening in return. Either sex may initiate courtship by approaching and brightening this way (Vincent, 1990).
Courtship in the wild is ordinarily conducted in the twilight hours of early morning in the wild. Courting begins with the partners approaching and brightening and ends when they move apart and resume their normal drab coloration again. There will be many such bouts of intense courtship over a period of days during the initial pair formation. Captive-bred seahorses often court more or less constantly and frequently continue courting throughout the day rather than confining themselves to the dawn displays typical of their wild conspecifics. This may simply be a response to a predator-free environment in which it is safe to remain bright and conspicuous regardless of the lighting conditions.
Courtship coloration varies from species to species. However, regardless of the colors involved, the head, dorsal surface (i.e., back), and ventral line (keel) of the seahorse normally remain quite dark while the rest of the body becomes lighter and dramatically intensifies in color (Vincent, 1990). Seahorses flaunt their brilliant coloration in order to impress prospective mates and the overall effect of this change is to make the seahorse much more conspicuous (Giwojna, Mar. 2002). Indeed, courting seahorses always remind me of a couple of excited teenagers dressing up for the prom (Giwojna, Mar. 2002).
When a seahorse is interested in romance, the stylish stallion dons his most dashing duds to impress his date, while his ladylove likewise dresses up in her most alluring attire, just as their human counterparts do (Giwojna, Mar. 2002). For example, consider the courtship colors of the Brazilian Seahorse (Hippocampus reidi): depending on their color phase, males often tend to prefer a flamboyant orange outfit while the fashionable females seem to favor more subtle shades of pastel pink (Giwojna, Mar. 2002). Hippocampus fuscus, the Sri Lanka Seapony, exchanges its somber, everyday black attire for a more enticing ensemble featuring pale cream and yellow colors when courting (Giwojna, Mar. 2002). As for the dark-colored European species, the short-snouted seahorse (Hippocampus hippocampus) changes to a shining white or silvery color, and the long-snouted Hippocampus guttulatus often switches to shades ranging from copper to light ochre or sulfur yellow, its body further adorned with tiny silver dots (Giwojna, Mar. 2002). As a general rule, tropical seahorses often undergo more pronounced color changes than temperate species, which tend to be more subdued.
Dwarf seahorses (Hippocampus zosterae) are not nearly as bright and flashy during courtship than their bigger brethren. These elfin creatures take on a different sort of glow. They sparkle looking as if they have been sprinkled with glitter, as they take on metallic tints, hues and highlights of their natural neutral colors. Tropical seahorse species generally rely on brightening and conspicuous color changes during courtship more than their temperate counterparts, which depend primarily on pouch displays such as Ballooning.
If all goes well during the approaching and brightening phase, the seahorses usually arrange themselves side by side while facing the same direction. The courtship will then proceed to the next stage with the couple looking their most dashing and debonair.
Reciprocal Quivering and Tilting.
In many seahorses, exchanges of quivering punctuate the next phase of courtship (Vincent, 1990). While perched side-by-side on the same hitching post, the partners adopt a characteristic posture and one of them — usually the male — begins to tremble and quaver. Holding its body stiffly erect with its pectoral fins fully extended, anchored firmly in place by its tail, the quivering begins with the fluttering of the dorsal fin and continues as a shudder that passes down its torso and quickly becomes a rapid sideways vibration of its entire body (Vincent, 1990). After a few moments the male will come to an abrupt halt and the quivering will stop as suddenly as began, only to be resumed by his partner a few seconds later. When the female’s trembling grinds to a halt, the male takes the cue and begins a new round of quivering, picking up where she left off. Back and forth, the seahorses take turns trembling and shuddering, and repeated bouts of these amazing gyrations may be exchanged for several minutes at a time (Vincent, 1990). The couple may entwine their tails during these displays of shimmying.
It’s interesting to note that both the tempo and vigor of the quivering are directly dependent on the size of the seahorses. The sideways shimmy becomes a rapid, high frequency vibration in small species like the dwarf seahorse (Hippocampus zosterae), whereas the movement is much slower in large seahorses like Hippocampus erectus, the lined seahorse. This big, buxom species sways back and forth in a stately, dignified manner. Rather than quivering, males of the larger species often merely “Tilt” towards their partners, a gesture which is akin to a polite, prolonged bow. Reciprocal quivering is an early phase of courtship that is quickly replaced by dancelike displays, but Tilting may still occur right through the final stages of courtship.
Tilting often serves as the warm up or precursor to quivering. Tilting typically begins with the male bowing toward the female and then righting himself again. These repetitive bows increase in frequency, transforming Tilting into full-blown displays of Reciprocal Quivering. Either partner may initiate the display with an exaggerated Tilt in which the seahorse leans over so far it’s almost lying on its side. The greater seahorses rarely progress past the preliminary Tilting phase, which is the more common of these two complementary performances.
Quivering is the least common of the seahorses’ courtship displays. It is seen much more often — or perhaps is just far more obvious — in dwarf seahorses and the smaller species. The larger breeds often skip over this step and get right down to dirty dancing as the male attempts to herd the female and she circles shyly away from him. Or they may simply Tilt or substitute a little slow motion, simultaneous, side-by-side swaying in place of reciprocal quivering, before busting out the real dance moves.
This delightful display is known as reciprocal quivering for obvious reasons. The male in particular appears to be energized — perhaps “stimulated” is a better description — by this activity. Encouraged by his partner’s enthusiastic response, he will eventually begin to rotate his body toward the female as he quivers. She will move away from him at first, maintaining her space, before returning his quiver (Vincent, 1990). He will then follow after her, attempting to close the distance between them while maintaining his grip on their common holdfast (Vincent, 1990). Quivering soon subsides altogether as she continues to move coyly away and they begin to circle around their hitching post in unison. The next phase of courtship has now begun.
Dancing (Carousel or Maypole).
These are the traditional dancelike displays most people associate with seahorses. They are seen in some form in the majority of seahorse species and dancing dominates the early phases of courtship in the greater seahorses (Vincent, 1990), which do much more of this wondrous underwater waltzing than the dwarf breeds.
Seahorses dance side by side and maintain a typical posture throughout these formal displays. They hold their bodies fully erect with perfect posture, tuck their heads, and conduct themselves with great dignity as they proceed, like ballroom dancers arrayed in tuxedos and formal gowns. The result is a graceful undersea ballet in which the partners grasp a common holdfast with their tails and slowly circle around it in full courtship regalia with all the elegance they can muster (Vincent, 1990). The pair stays in perfect unison as they perform this circling dance in all their finery. Their rigid posture and bright colors irresistibly remind anyone who witnesses this display of the pairs of painted ponies and stately steeds that circle ceaselessly around a merry-go-round at the amusement park. Small wonder then that the researchers who first observed this behavior dubbed it “the Carousel dance.”
Sometimes a pair begins carouseling atop a tall hitching post and spiral slowly downward until they reach the bottom again (Vincent, 1990). This lovely variation of the Carousel dance is known as the Maypole dance for obvious reasons. Together these dances play an integral role in pair formation and daily greetings for most tropical seahorses (Vincent, 1990).
Periodically the prospective partners will interrupt their passionate pas-de-deus long enough to move from one holdfast to another. They do not discontinue their courtship displays when they are on the move, as you might expect. Rather they simply switch from carouseling to a different type of dancing that’s better suited for covering ground. This is a type of highly stylized, side-by-side synchronized swimming known as the Parallel Promenade.
When promenading this way, the graceful movement of the seahorses is best described as prancing or strutting. The courting couple maintains precisely the same posture and carry themselves exactly the same way as four-legged horses do when prancing. That is, their bodies are erect with their heads held high, but inclined downwards, so as to keep their chins, errr — their snouts tucked tightly against their necks (Vincent, 1990). The pair swims side by side, facing the same direction, in tight parallel formation as they move from one hitching post to the next (Vincent, 1990). They travel in tandem as if harnessed together as a team. Their tails are often intertwined when they promenade, looking for all the world like a young couple shyly holding hands as they stroll the boardwalk.
Just occasionally, the male Tilts toward the female as they promenade, as if drawn irresistibly toward his partner (Vincent, 1990). If carried far enough, the tilt may become a tremor and then a sideways trembling, and if the female actively cooperates, an impromptu round of reciprocal quivering may result, particularly in miniature species. Eventually the overexcited male will regain his composure, and the promenade will proceed to its intended destination, where more Carousel dancing will ensue.
Like the other dances, promenading is an early stage of courtship seen primarily in large tropical seahorses (Vincent, 1990).
Pumping and Ballooning.
Pumping and Ballooning are pouch display performed to some extent by all male seahorses regardless of species. The energetic display known as "Pumping" is a vital part of the courtship ritual in all seahorse species that have been studied to date. Temperate and tropical seahorses alike, from the smallest pygmy ponies to the largest of the "giant" species, it appears that all male seahorses perform such pouch displays.
Pumping requires a series of coordinated movements. Bending vigorously, the aroused male jackknifes his tail to meet his trunk, thereby compressing his inflated brood pouch in the middle. The male then straightens up again, suddenly snapping back to “attention” so as to relieve the pressure on his severely compressed midsection. This rapid pumping motion has the effect of forcing water in and out of the brood pouch in a manner that is virtually identical to the way the young are expelled at birth (Vincent, 1990).
The strenuous pumping action is the stallion’s way of demonstrating his pouch is empty of eggs and that he is a strong, healthy, vigorous specimen capable of carrying countless eggs (Vincent, 1990). By so doing, he assures the female that he is ready, willing, and able to mate, and that he can successfully carry and deliver her entire brood.
Pumping is an impressive display to say the least. Perhaps a bit too impressive at times. For example, I often receive emergency emails, urgent instant messages, and frantic phone calls from novice seahorse keepers who have just observed their stallions performing for the first time and are convinced something is horribly wrong. To their untrained eyes, the poor creatures appear to be in the midst of an acute attack of appendicitis or an epileptic fit, if not their death throes. The alarmed hobbyists are certain their poor pets are having violent convulsions and proceed to describe in lurid detail how the pitiful ponies are doubling over in obvious agony again and again, in the grip of seizures so severe they are all but being torn in two.
It is my great pleasure to reassure them that all is well, and that their ailing male is actually happy and healthy and very much at home in their tank to the point that he is displaying a hearty interest in mating. Indeed, the courtship display they are witnessing is an unmistakable indication that they are doing things right and that their male is quite content with the conditions they have created in the aquarium. One might only wish that all seahorse crises were so easily dismissed, so quickly resolved, and with such a happy outcome.
Courtship in many temperate and subtemperate seahorses is dominated by such pouch displays. In addition to pumping, these coldwater ponies also engage in a different type of pouch display known as “Ballooning.” This is a simple display in which they inflate their brood pouches to the fullest possible extent and parade around in front of the female in all their glory as though trying to impress her with the sheer dimensions of their pouches. The pumped up paramours perform proudly, putting on quite a show for the flirtatious fillies. (All you ladies out there are surely all too familiar with this act. No doubt you attract the same sort of attention and elicit the same type of behavior every summer at muscle beach, where all the macho men pump up their biceps, suck in their guts, and throw out their chests whenever you stroll past.)
Often all the males in the vicinity will compete for the attention of the same female, chasing after her with their pouches fully inflated this way. When all the boys are in full-blown pursuit of a female ripe with eggs, they look like a flotilla of hot air balloons racing to the finish line.
Hippocampus abdominalis, H. breviceps, and H. tuberculatus, in particular, have developed enormous pouches that are all out of proportion to their bodies when fully expanded. Their oversized pouches look like over-inflated balloons ready to burst when these stallions come a courting. Take the tiny Hippocampus breviceps, for example. With its brood pouch expanded to the maximum, a courting male looks like a fuzzy 3-inch pipe cleaner that swallowed a golf ball! Courtship in temperate/subtemperate species generally centers on pouch displays more than color changes, dancing or prancing.
Pumping is one of the final stages of courtship and it indicates the seahorses are really getting serious (Vincent, 1990). Mating will take place shortly, as soon as the female hydrates her eggs, unless something intervenes in the interim.
Pumping probably serves several important functions simultaneously, making it the courting male’s method of multitasking. It is an important part of pouch preparation and certainly indicates the stallion’s readiness to breed. No doubt Pumping also provides the female with a means of judging the merits of prospective mates. She will generally favor the stud with the greatest stamina and the largest brood pouch. And there is a growing body of evidence that suggests pumping males are releasing sex hormones that stimulate the female to ripen her eggs in preparation for ovulation, secure in the knowledge that a receptive male will be standing by, ready to receive them.
Eventually, the female will respond to repeated bouts of Pumping with a display known as Pointing, thereby signaling her eagerness to rise for the exchange of eggs.
Pointing is the prelude to mating and the transfer of the eggs. The female’s eggs will have been fully hydrated by this time, as indicated by the rounded appearance of her obviously swollen abdomen and the protrusion of her oviduct or genital papilla (Vincent, 1990). At this point, she will be anxious, even desperate, to mate. In order to ensure fertilization, the female must add water to her mature oocytes (egg cells) just prior to mating (Vincent, 1990). A ripe female is committed to mating once she has hydrated her clutch of eggs. She cannot retain the hydrated eggs indefinitely (Vincent, 1990). They can only be retained for approximately 24 hours, before they must be released. She must transfer these eggs to a receptive male within 24 hours of hydration, or lose the entire clutch.
Should she be unable to transfer them to a receptive male within that time, she risks becoming egg bound, and her only recourse is to release them into the water column, spilling her eggs onto the substrate. This is an expensive waste of precious bodily resources that must be avoided at all costs. In fact, the whole purpose of the elaborate courtship ritual developed by Hippocampus is to assure that a receptive male is standing by at the crucial moment, ready, willing and eager to accept the eggs.
The ripe female signals her urgency by "Pointing" — rising on the tip of her fully extended tail and stretching vertically towards the surface of the water while raising her upturned head until her snout points straight up (Vincent, 1990). It looks almost as if the female is answering the male’s overtures by nodding her head in assent.
Pointing is an unmistakable sign that the female is ready to rise for the nuptial embrace, which will soon take place in midwater (Vincent, 1990). Pointing thus triggers an immediate response from the male, who typically reacts by Pumping or Tilting (Vincent, 1990). At first there is a stimulus-response relationship between the pointing of the female and the pumping of the male, with one eliciting the other. This helps to coordinate the couple’s courtship, assuring that both partners are fully aroused and physiologically prepared for the transfer of eggs when the moment arrives. There is a direct correlation between the frequency of pointing and pumping and the arousal level of the female and male, and one can easily judge how soon mating will occur by noting the tempo and vigor with which they perform these maneuvers. When mating is imminent, the male often responds not by pumping, but by echoing the female’s Point with one of his own (Vincent, 1990).
If he does not take the hint fast enough, the female will push off the bottom in mid-Point and rise up alone, enticing the male to follow. After a few of these solo rises, the male will eventually get the idea, and prepare to follow her lead. The couple will then rise together for the culmination of their courtship.
This is the final phase of courtship. It is the climax of the entire affair during which the partners meet in midwater for the transfer of the eggs (Vincent, 1990). The female initiates the rise by pushing up from the bottom in mid-Point and the male immediately follows her lead. They ascend through the water column facing each other, with their heads raised high and their abdomens thrust forward (Vincent, 1990). At this point, the female’s genital papillae or oviduct will be everted and protrude slightly from her vent, and the male’s brood pouch is usually fully inflated (Vincent, 1990). As they ascend, the female often continues to Point and the male may continue to Pump (Vincent, 1990). They will meet at the apex of their rise for the nuptial embrace.
The actual transfer of eggs takes place while the couple is suspended in midwater or slowly descending toward the bottom — a maneuver that is every bit as tricky as it sounds. Coitus is marked by an extremely awkward, fleeting embrace, aptly described as little more than a brief belly-to-belly bumping (Vincent, 1990). (Brief and fleeting as in if one dares to blink, take a bathroom break, or run for your camera you may miss what you have waited all this time to witness!) As you can imagine, many difficult and delicate maneuvers are required to bring the pair into proper position for this most improbable merging. The female will attempt to insert her oviduct into the gaping aperture of the male’s inflated brood pouch. An inexperienced pair will often end up misaligned, perhaps at right angles to one another or with one of the partners too high or too low to join. This is very typical of the many false starts and abortive attempts that are ordinarily involved. The frustrated couple will separate to rest on the bottom prior to successive attempts. They may require many such rises before the proper positioning is achieved and the crucial connection is finally made.
The female will eventually succeed, with the full and active cooperation of her mate. He positions himself slightly below his mate, with the aperture of his pouch fully dilated and gaping open, ready to receive her eggs. The female will hover directly over the aperture until she can actually insert her oviduct into the opening at the top of his brood pouch or drop her eggs into the basket while hovering directly above the pouch. Pairs occasionally entwine tails when joined, but more often than not their tails will be stretched back behind them, out of the way.
If she makes a good connection, she will extrude her eggs in one long, sticky string, and the pair will hang together in midwater while the transfer is completed, drifting slowly downward as the eggs surge downward deep inside the pouch (Vincent, 1990). The entire clutch — up to 1600 eggs — is transferred in one brief embrace lasting a mere 5-10 seconds (Vincent, 1990). Sperm stream from the male’s urogenital pore into the pouch opening as the eggs are deposited (Vincent, 1990). The couple separates as they descend, drifting slowly toward the substrate. Exhausted by their efforts, the pair seek out comfortable hitching posts for a well-deserved rest. One almost expects to see them light up cigarettes at this point.
The pregnancy-sustaining changes in the male’s pouch begin the moment the last egg is tucked safely away inside this protective pocket. The male’s pouch deflates, compressing the eggs against the pouch lining in order to facilitate implantation. The male then perches and attempts to settle the eggs properly in his pouch, often undergoing a series of agitated contortions, swaying, twitching, or wagging his tail from side to side, and perhaps stretching as though trying to rearrange the eggs more comfortably (Vincent, 1990). He is dispersing the eggs uniformly throughout his pouch, giving each one the best chance to be fertilized and implant in the septum or wall of the marsupium.
Meanwhile, the female’s belly slims down noticeably as she transfers her eggs. She may lose up to 30% of her body weight after depositing a large clutch of eggs (Vincent, 1990). As a result, her abdominal plates or belly rings will be concave or pinched in for the next couple of days.
The seahorse’s charming courtship rituals and delightful displays are a wonder to behold. The grace and beauty of the courtship dance, with its carousel-like ballet and elegant parallel promenade, the rhythmical swaying and passionate performances of "Pointing" and "Pumping," and the fabulous midwater finale all combine to create an unforgettable spectacle that’s unprecedented in all of nature.
Now that you are familiar with the different courtship displays that are commonly seen in the genus Hippocampus, let’s examine how these ritualized behaviors work together during pair bonding for a typical tropical or subtropical seahorse.
Initial Pair Formation.
The first time seahorses pair up they court on and off for several days prior to the actual transfer of eggs (Vincent, 1990). The active participation of the female throughout this prolonged courtship is quite unusual for fish. In general, female fish engage in very little if any pre-spawning or pre-mating behavior (Evans, 1998). As a rule, in most fishes, the female’s involvement is largely limited to the exchange of gametes itself when mating occurs (Evans, 1998). But in Hippocampus, unorthodox behavior is the rule, and the female is a full partner in all the pre-game preparations and preliminary proceedings. Her complete cooperation and active participation is required throughout the courtship if bonding is to occur.
The elaborate courtship ritual may be initiated by either gender (Vincent, 1990). If the courtship is to be successful, when one of the seahorses makes an advance, its partner must respond accordingly at every step along the way (Giwojna, Mar. 2002). Thus in the initial phase of courtship, when one seahorse brightens and approaches the other, its partner should brighten in return. Likewise, when the female begins to ”point” in the later stages of courtship, the male must react by ”pumping” or echoing her with a ”point” of his own (Giwojna, Mar. 2002). Invitations to dance must be accepted and so on. If that does not happen — if each overture is not answered with an appropriate response — the lines of communication will break down, the courtship cannot advance to the next stage, and the pairing will fail (Giwojna, Mar. 2002). A lasting pair bond is forged when everything goes smoothly and mating results. This is how the initial courtship generally proceeds:
Social activities in general and courtship in particular are concentrated in the early morning hours (Vincent, 1990). The amorous affair begins when a male and female approach one another shortly after dawn, signaling their readiness to spawn by brightening in coloration (Giwojna, Mar. 2002). If the partner that is approached is receptive and responds affirmatively by brightening in return, courting will begin in earnest (Vincent, 1990).
The initial day of courtship is typically very busy (Vincent, 1990). Aside from flaunting their newfound finery, the courting couple devotes much of the first day to three main activities — carouseling, Maypole dancing and promenading, which are all highly ritualized dancelike displays (Giwojna, Mar. 2002).
The choreography of the first day begins when the male and female both take hold of the same hitching post with their tails, circling around and around this pivot point in tandem, as if it were a Maypole (Vincent, 1990). The pinwheeling pair periodically interrupt their stately carousel dance long enough to swim side-by-side along the bottom to another nearby holdfast, often with their tails linked (Giwojna, Mar. 2002). Once there, they continue carouseling and resume their majestic Maypole dance momentarily before moving on to the next convenient perch to repeat the entire procedure.
Repeated bouts of carouseling and promenading are performed throughout the morning hours, with the couple taking occasional dance breaks to rest up between performances (Vincent, 1990). From time to time, a flurry of reciprocal quivering may break out in the midst of all the waltzing (Vincent, 1990), but this dirty dancing doesn’t last long and as soon as the shimmies die down again, the pair goes right back to their stately ballroom dancing.
These same basic maneuvers are repeated again on the second morning, albeit at a slower pace (Vincent, 1990). Once the excitement of the first day has worn off, the graceful carousel-like ballet and synchronized side-by-side swimming are performed much less often and less fervently, making the second day of courtship relatively quiet.
The activity level of the pair picks up sharply again the following morning, and the pace of courtship reaches a new peak by the third day (Vincent, 1990). The dance tempo picks up as the partners become more excited and increases steadily throughout the morning, building to a crescendo over a period of several hours (Giwojna, Mar. 2002).
At this point, two new behaviors begin to appear and dominate the final day of courtship: the male’s vigorous pouch displays and the female’s urgent pointing (Vincent, 1990). After several hours of intense courtship that morning, the female will have fully hydrated her eggs, as indicated by her very rounded abdomen and the first indications of her oviduct, and with the clock ticking, she will be eager and impatient to mate (Vincent, 1990). The ripe female responds to the pumping of her partner and signals her need by rising up on the tip of her fully extended tail and stretching vertically towards the surface of the water in full Point (Giwojna, Mar. 2002). The partners may then exchange “Pumps” and “Points” back and forth with increasing vigor for some time before they are both ready for the climax of their courtship.
These passionate displays of pointing and pumping typically reach their peak during the late morning or early afternoon hours of the third of fourth day of courtship. Spurred on by her sense of growing urgency, the pointing of the overripe female will be driven to new heights of intensity, until she is stretching upwards desperately as if frantic to rise to the surface (Giwojna, Mar. 2002). At some point, the equally excited male will follow her lead and push up from the bottom. The seahorses will be at their very brightest as they ascend through the water together facing one another for the transfer of the eggs (Giwojna, Mar. 2002). Mating is the culmination of courtship that binds the couple together, signifying the formation of a new pair.
Pair formation proceeds somewhat differently in temperate species. Males from temperate zones typically eschew the color changes and circling carousel dances of the tropical stallions in favor of dramatic pouch displays. They will inflate their brood pouches to the bursting point, so that the thinly stretched skin over their pouches becomes white and conspicuous, and parade around a female in all their masculine magnificence (Kuiter 2004b). The idea is apparently for these pumped-up paramours to impress prospective partners with the preposterous proportions of their prodigious pouches, thereby demonstrating their obvious fitness and ability to successfully carry a large clutch of eggs. During the breeding season, these displays of Ballooning are repeated every morning, after which the pair separates to forage within the same vicinity, allowing the partners to remain in contact with each other from day to day (Kuiter 2004b). Once the pair is physiologically attuned and mating is imminent, the pouch displays will be repeated several times during the course of the same day until the female has hydrated her ripened eggs and begins to Point (Kuiter 2004b). The copulatory rise and transfer of eggs will follow shortly thereafter.
In monogamous species, once seahorses have paired up, they will continue to strengthen and renew their bonds with a daily greeting ritual, and subsequent matings will normally take place hours after the male has delivered his latest brood (Vincent, 1990). The morning greeting rituals are fleeting versions of the seahorses’ typical courtship displays. Thus in temperate seahorses, the stallions greet the mares with ballooned pouches (Kuiter 2004b), whereas morning greetings in tropical species involve brightening and carouseling.
Okay, Amanda, that you give you a pretty good idea of what to look for when you’re seahorses are getting serious about courtship and breeding, which may already be the case, at least for the H. reidi. As for what conditions are conducive for breeding, in order to set up housekeeping your seahorses will require sufficient water depth to complete the copulatory rise and mate comfortably and at least 12 hours of daylight to trigger the release of gonadotropin. (Insufficient water depths effectively prevents breeding in seahorses, and breeding shuts down in some species if they do not receive a certain number of hours of daylight over the course of the day.) So water depth and photoperiod are two of the key factors that influence reproduction in seahorses. Otherwise, concentrate on providing them with optimal water quality, a stress-free environment, and a highly nutritious diet, and then just let nature take its course.
Yes, a greenwater nursery is a good choice for pelagic seahorse fry such as H. erectus and H. reidi, Amanda. You can use the greenwater in any type of nursery with the exception of in-tank nursuries, so you have a lot of flexibility regarding the nursery setup that will work best for you. Hippocampus reidi fry almost all ways do best in a kriesel or pseudo-kreisel nersery tank, especially when it is filled with greenwater, but H. erectus fry can do well in a more basic nursery. The nersery tank should have gentle aeration and a heater to help keep the water temperature stable. Most nursuries do not have filters because they tend to produce water movement that is too strong for the newborns and also have a bad habit of "eating" all of the newly hatched brine shrimp, copepods, or rotifers the babies need to eat. A small air-driven sponge filter is sometimes included in the nursery, with the gang valve to adjust the air stream so it is very gentle, but most of the time water quality is maintained in nursery tanks by performing small daily water changes carried out while siphoning fecal pallets from the bare bottom of the tank.
Best of luck with your prolific ponies and their future progeny, Amanda!