seahorse life span

Dear Amanda:

There are currently 16 different species comprising 21 distinct types of captive-bred-and-raised seahorses available in the US, and to my knowledge, none of them are commonly known as "green seahorses." Without a better description or perhaps a photograph to go on, I’m afraid the identity of your mystery seahorses will have to remain an enigma for now.

It’s difficult to say how long you can expect your new seahorses to live without knowing what species they are, but I can tell you that with the exception of dwarf seahorses (Hippocampus zosterae), which typically only survive in the wild for a year or so, all of the seahorses we commonly keep have life spans longer than 2-4 years.

For example, in my experience, cultured seahorses such as Mustangs and Sunbursts (Hippocampus erectus) have a life expectancy of 8-10 years in captivity, it provided with good care, but a life span of 4-6 years is more typical in the home aquarium. (I personally know of one old war horse raised by a colleague of mine that reached the ripe old age of 7 years and 3 months.) At the Ocean Rider facility, I believe some of their original broodstock are older still (10+ years old), but of course the ideal conditions there are far different from the small,-closed-system aquaria and artificial saltwater we hobbyists must rely on.

In short, with proper care your green seahorses should be with you for several years. Best of luck with your new seahorses, Amanda!

Happy Trails!
Pete Giwojna

Dear Amanda:

Congratulations on your mated pairs! A healthy interest in breeding and mating is a sure sign that your seahorses feel right at home in your aquarium.

As a rule, captive-bred-and-raised seahorses are highly gregarious animals that very much appreciate the company of others of their kind and are accustomed to being surrounded by other seahorses. So introducing another female as a potential mate for your bachelor male should not disrupt your herd or cause any problems, provided that adding a new seahorse won’t make your aquarium overcrowded her over catch the biofilter.

However, I wouldn’t do it unless you can obtain a female that is the same species as the rest of your seahorses. Two seahorses of different species are unlikely to pair up and mate. They will occasionally do so, but even when intraspecific crossbreeding occurs, the hybrid offspring that result are generally undesirable for various reasons.

So let’s see if we can identify your green seahorses first, and then we can try to find your lonely stallion a suitable mate of the same species. If you can provide us with a good photograph or two and a better description of your seahorses, we will have a much better chance of identifying the species, and we can proceed from there.

Best of luck with your new seahorses, Amanda! Here’s hoping your mated pairs provide you with plenty of healthy offspring!

Happy Trails!
Pete Giwojna

thank you harry for info i have looked at some of the seahorses on this web and their are one or two they look like but as for sending a photo i can,t figure out how to send them thanks again amanda

Dear Amanda:

I’m sorry it took me this long to get back to you about your photographs, but I misplaced your e-mail address and have resorted to contacting you here on the messageboard as a result.

After closely examining the pictures, I’ve narrowed down the identification of your mystery seahorses from 22 possibilities to the following 3 captive-bred-and-raised species:

Hippocampus kuda (most likely)
Hippocampus reidi (slightly less likely)
hippocampus kelloggi (least likely)

Those are all large, smooth bodied, tropical seahorses with similar color patterns to your specimens, Amanda. To be a 100% certain of the identification, I would have to do meristic counts on your seahorses, but I was not able to count the number of tail rings on your seahorses from the pictures, much less count the number of rays on their dorsal, pectoral and anal fins.

However, I believe you can determine which of those three species you have by closely scrutinizing the crown-like coronets atop their heads at home, Amanda. For example, the coronet of H. kelloggi is medium-high, with five short spines, and a distinctive high plate in front of the crown. It is the only one of the three possibilities that has spines on its crown. The spines are short but sharp, giving its coronet the appearance of a five-pointed crown when seen from above. So if the coronet of your seahorses has those five small spines or sharp points, Amanda, then we can be pretty certain that they are Hippocampus kelloggi, and if their coronet does not have those five small sharp spines, then we can rule out H. kelloggi.

Both H. reidi and H. kuda have rounded coronets that are free of spines, but in H. reidi is rounded coronet is low to medium in height but may be quite large and convoluted (like a crumpled piece of paper). In H. kuda, the rounded coronet is also low to medium in height, but typically overhangs at the back, and often has a cup-like depression in the top; sometimes with broad flanges. So if the crowns on the heads of your seahorses are free of spines or sharp points, but are convoluted, then they are probably reidi; if they are free of spines or sharp points and overhang at the back, or have a cuplike depression in the middle, then they are most likely H. kuda.

So take a close look at the coronets of your seahorses, Amanda, and see which of the above they most closely resemble. Also check out the photographs of H. kelloggi, H. kuda and H. reidi online, and see which species your seahorses most closely resemble.

Best of luck with your new seahorses, Amanda!

Happy Trails!
Pete Giwojna

Dear Amanda:

You’re very welcome! Okay, if your seahorses are Hippocampus reidi, you should be able to find a mate for your unpaired seahorse without too much difficulty. Brazilian seahorses (H. reidi) are very popular and captive-bread-and-raised specimens are available from several different sources in the US. For example, Ocean Rider offers both yellow Brazileros (H. reidi) and red Brazileros (which are usually bright orange).

Yes, the male with the swollen brood pouch you thought was expecting may simply have been inflating his pouch with water, or he may indeed have been pregnant only to have something disrupt the pregnancy.

As you know, male seahorses perform pouch displays known as "Pumping" and "Ballooning" when they are courting during which they inflate their pouches with water.
Ballooning is a simple display in which courting males fill their brood pouches with water 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.

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 around pouch displays more than color changes, dancing or prancing.

However, ballooning is much more common in temperate seahorses than tropical species, Amanda. If your male is a Brazilian seahorse (H. reidi) or any other tropical species of seahorse, which is almost certain, then he is much more likely to be engaging in a different type of pouch display known as "Pumping" instead.

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. The male’s marsupium also becomes grossly distended during displays of Pumping, but in that case, it is obvious the male is courting because it looks like he’s doing abdominal crunches as the vigorously pumps water in and out of his brood pouch.

During displays of Ballooning and Pumping, the male’s pouch is inflated with seawater, so he maintains neutral buoyancy and can swim normally. As a rule, males don’t perform these pouch displays if they are pregnant. The intrusion of saltwater into the pouch can be harmful to the embryonic young in the early stages of pregnancy because it dilutes or displaces the marsupial fluid that is bathing the fetal fry, and opening the pouch in the later stages of pregnancy is equally disastrous since it may result in the expulsion of pug-nosed preemies still attached to yolk sacs. Ordinarily, once a male seals the aperture of his pouch after the transfer of the eggs, he will not open it again until the hormone isotocin triggers parturition and the birth spasms. So if your male with the enormous pouch has merely been performing displays of Ballooning or Pumping, then he was not actually pregnant, just trying to entice one of your females to mate with him so that he could become pregnant.

On the other hand, Amanda, it’s quite possible that the male with the distended pouch could have been pregnant but that something has interrupted the normal course of the pregnancy and caused him to resorb the eggs and fetal fry. When that happens, hobbyists often describe the phenomenon as a phantom pregnancy or a false pregnancy.

A "phantom pregnancy" is not an altogether uncommon phenomenon with seahorses in the aquarium. In seahorses, a hormone known as fish isotocin, which is the equivalent of oxytocin in mammals, triggers parturition or giving birth (Vincent, 1990). Thus anything that stimulates excess secretion of isotocin can result in premature births, whereas anything which decreases or delays the secretion of isotocin can postpone delivery and prolong a pregnancy abnormally. In a similar manner, disruption of other hormones can cause a male to spontaneously abort a pregnancy or to actually resorb the eggs. The placenta-like changes that take place in brood pouch, the development of the young, and the pregnancy itself are all controlled by various hormones — testosterone, adrenal corticoids, prolactin, and isotocin (Vincent, 1990) — so basically anything that influences the secretion of those key hormones can have a profound effect on the pregnancy.

Some of the factors that influence these hormonal responses are the presence of the female, low oxygen levels, heat stress, and diet. The presence of the female most definitely influences the gestation and brood success of her mate. Numerous studies indicate that the presence of female fishes visually or hormonally stimulates male sexual activity such as courtship, nest building, and the development of androgen-dependent sexual characteristics (Vincent, 1990). Research has also shown conclusively that male seahorses which have been with the same female for more than one mating cycle are markedly more successful in brooding young (Vincent, 1990). It is believed that one of the reasons for this is that the presence of their mate stimulates the secretion of the corticoids (steroid hormones produced by the adrenal cortex) and prolactin that control the pouch environment and maintain the incubation (Vincent, 1990). The male is thought to further expand his pouch and develop the placenta-like internal structures to a greater degree as a result (Giwojna, Feb. 2002). More of the eggs can then be successfully implanted and carried to full term (Giwojna, Feb. 2002). Separating a gravid male from his mate can therefore have a negative impact on his pregnancy and should be strictly avoided.

Low oxygen levels during pregnancy can likewise be disastrous. They result in respiratory distress for the gravid male, putting the embryonic young at risk, as well as directly altering the hormones we have been discussing, which can further disrupt the pregnancy.

Heat stress is doubly bad news for gravid males. Not only can abnormally warm temperatures disrupt the secretion of these key hormones and shut down breeding, they can also directly denature long chain polymers and macromolecules (e.g., proteins, enzymes and hormones) by altering certain bonds and changing the three-dimensional shape of the molecule on the atomic level. And, of course, water temperature also directly affect the metabolism of the seahorse and therefore its gestation period. Up to a certain point, increasing water temperatures will shorten the normal gestation period, just as decreasing water temperature will prolong or extend gestation.

Past a certain point, however, when the increasing temperatures exceed the comfort range for the seahorses, elevated temperatures will bring reproduction to an abrupt halt. For example, the Mexican population of H. ingens begins breeding in late September when the water temperatures decreases below 81°F (27°C), and keep breeding until late May when the water temperatures increase above 80°F again (Eliezer Zúñiga, pers. comm.).

An inadequate diet can also be detrimental to a gravid male for obvious reasons. Maintaining a large brood of developing young can be a big drain on the male’s bodily resources, and a nutritious diet rich in HUFA and essential fatty acids is necessary at this time to help the male keep up his strength. That is why male seahorses have an intestinal tract that’s 50% longer than that of females (Tamaru, Aug. 2001). They need the extra food absorption ability and digestion a longer intestine provides in order to sustain the metabolic demands of up to 1600 rapidly growing fry.

When factors such as these disrupt the pregnancy, it’s not so much a case of "false pregnancy" as a failed pregnancy — a gravid male that was not able to carry his brood of embryonic young and fetal fry to full term due to the sorts of developments we have been discussing. This is how Carol Cozzi-Schmarr describes the situation: "If… conditions are not optimum and the general stress level of the male is too high, the male will simply re-absorb the eggs or abort them. You will sadly think that he was never really pregnant."

It’s possible something like that may have happened with your male that appeared to be pregnant for a couple of weeks, although ultimately nothing came to fruition, Amanda.

Best of luck finding another H. reidi mate for your seahorses, Amanda!

Happy Trails!
Pete Giwojna

Dear Amanda:

Congratulations on your surprise brood of babies! It’s good to hear that your stallion wasn’t just performing pouch displays or experiencing a Phantom pregnancy, but actually carrying a healthy brood of developing young.

Now that they have begun breeding, I have good news and bad news about your Brazilian seahorses (Hippocampus reidi). The good news is that they are the most prolific of all the seahorses and should now produce a new brood of babies for you every 2-3 weeks. What’s more, they can produce extremely large broods consisting of several hundred newborns. The bad news is that H. reidi babies are especially difficult to raise, as discussed below.

Hippocampus reidi are famous among seahorse keepers for two things: brilliant colors and making babies. The Brazilian breeding machine is the most prolific of all the seahorses (Abbott 2003). They have a well-deserved reputation for churning out brood after brood every two weeks with relentless regularity, and hold the world record for delivering ~1600 young in a single brood (anecdotal reports of broods up to 2000 fry are not uncommon)! Not bad for a livebearer. But with that many fetal fry crammed into one incubator pouch, the inevitable tradeoff is that the young are born at a considerably smaller size than most seahorses (Abbott 2003). They also go through a lengthy pelagic phase, drifting freely with the plankton for up to 1-2 months, which makes H. reidi fry notoriously difficult to raise (Abbott 2003).

The phenomenal output of offspring H. reidi produces is a mixed blessing for hobbyists (Giwojna, Jun. 2002). When combined with the promiscuous nature of captive-bred Brazilians, it means their owners are treated to one of the grandest spectacles in all of nature with delightful regularity — the colorful courtship and love dance of the seahorse (Giwojna, Jun. 2002). Brazilians favor particularly brilliant courtship colors, such as hot pink and tangerine, so the opportunity to observe the unparalleled pageantry and charming choreography of their courtship displays so often is a marvelous bonus for aquarists (Giwojna, Jun. 2002).

On the other hand, the short gestation period combined with those huge broods means that the newborn Brazilian fry are smaller and less well developed than most other seahorses (Giwojna, Jun. 2002). Many of them will be too small to accept newly hatched Artemia nauplii as their first food, and the fry undergo a prolonged pelagic phase, during which they drift freely amidst the plankton for the 1-2 months of their lives (Giwojna, Jun. 2002). The pelagic fry tend to gulp air and cling to the surface, making surface huggers and floaters with buoyancy problems a constant threat (Giwojna, Jun. 2002). Survivorship is typically quite low and the entire brood is often lost. Even accomplished breeders often struggle with this species (Giwojna, Jun. 2002).

Unfortunately, your reidi babies are not suitable for the easy rearing method and require the more complicated "food-chain" method of rearing, as described in the following online article, which will also explain why H. reidi fry are harder to raise than others and discuss how to culture live foods for the fry:

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Nutrition – Feeding & Rear
http://www.seahorse.com/FAMA_-_Freshwater_and_Marine_Aquarium_magazine/Horse_Forum_-_Nutrition/ Nutrition_-_Feeding_%26_Rearing_the_Fry_-_Part_IV/

In addition, the following threads on this discussion forum are also devoted to raising seahorse babies and should have a lot of information you will find useful in your quest:

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:I had Babies!! – Ocean
http://www.seahorse.com/option,com_simpleboard/Itemid,/func,view/catid,2/id,1299/#1299

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:Babies – Ocean Rider Cl
http://www.seahorse.com/option,com_simpleboard/Itemid,/func,view/catid,2/id,1316/#1316

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:suitable Fry Container
http://www.seahorse.com/option,com_simpleboard/Itemid,/func,view/catid,2/id,863/#863

Be sure to check out the following discussions regarding the best methods for raising H. reidi fry as well:

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:raising redi – Ocean Ri
http://www.seahorse.com/option,com_simpleboard/Itemid,/func,view/catid,2/id,1164/#1164

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:reidi fry no survivors
http://www.seahorse.com/option,com_simpleboard/Itemid,/func,view/catid,2/id,1054/#1054

Best of luck with your prolific ponies and all their progeny, Amanda!

Happy Trails!
Pete Giwojna