- This topic has 5 replies, 2 voices, and was last updated 15 years, 7 months ago by Pete Giwojna.
July 2, 2008 at 7:52 am #1485BigGrantmanMember
I\’m always pushing the limits and I got a male seahorse for my biocube. well it happened the male became pregnant. well the males pouch stayed puffed up for almost two weeks and than today the pouch is half the size it was. I didn\’t see any babies though. When i did my normal rounds today i notice him kinda curling over and opening the pouch without anything coming out. What happened!!!!:dry: :S
Post edited by: BigGrantman, at: 2008/07/02 04:41July 2, 2008 at 9:50 pm #4308Pete GiwojnaGuest
It’s difficult to say what’s going on with your stallion, sir. It’s possible that something may have disrupted the pregnancy and caused the male to resorb the eggs and/or embryonic young, or it’s possible that he may have given birth in the early morning hours and that the filters or his tankmates may have eaten the newborns.
For example, it’s not unusual for a gravid male to release a fraction of his brood a bit prematurely, only to shut down operations temporarily and then deliver the rest of the young normally a few days later. When that’s the case, the remainder of the brood is typically released en masse 2-4 days after the first batch of fry were expelled. If it’s been nearly 2 weeks since your male became pregnant, he may have delivered a portion of his brood shortly before or after sunrise, which is when the vast majority of males give birth, and this first batch of newborns may have been filtered out by your filtration system or predated by his tankmates, leaving none of the young for you to find. You might want to check your prefilter and filter box for any sign of the seahorse fry, just in case.
Otherwise, I suspect that something may have disrupted the normal course of the pregnancy and prevented your male from completing gestation. When that happens and gestation is interrupted, hobbyists often describe the phenomenon as a phantom pregnancy or a false pregnancy or a miscarriage.
Several things can interrupt a pregnancy and cause a gravid male to lose the embryonic young or fetal fry he is carrying. For example, 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, diet and, of course, stress. 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. (So check the dissolved oxygen levels in your Biocube, Grant!)
Poor water quality — especially ammonia and/or nitrite spikes — are one of the most common aquarium stressors that can disrupt hormones and interrupt a pregnancy. Stress hormones such as cortisol will be released in response to such stressors, at the expense of other adrenal hormones, which can have a negative impact on the pregnancy and the developing fry.
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 affects 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."
So the actions of the aquarist and the aquarium conditions can have a big effect on how well a pregnancy progresses, and whether or not the fetal fry develop normally and are brought to full term, or are aborted, delivered prematurely, or resorbed as embryos. In short, it’s important to handle gravid males with care and to provide them with a nutritious diet, optimal water quality, good levels of dissolved oxygen, and a stress-free environment at all times. Those are the most important things you can do to prevent the recurrence of this problem in the future, Grant.
Best of luck with your seahorses, sir! Here’s hoping that your pair provides you with a healthy brood very soon.
Pete GiwojnaJuly 3, 2008 at 7:38 am #4309BigGrantmanGuest
Thats what I’m worried about all of a sudden it is like she runs from him. sometimes they hold tails and stay close. but other times she runs. is he a bad male or what is wrong. also why was the male having contractions and opening the pouch with nothing coming out. so did i mess up. also i have a reef question if you can help. my green button polyps all of a sudden like died back and now its like the other corals aren’t opening fully. i suspect the zoa’s are releasing chemicals. the zoa’s are in my 75 gal. Thanks Grant
Post edited by: BigGrantman, at: 2008/07/03 03:41July 3, 2008 at 10:40 pm #4310Pete GiwojnaGuest
No, sir, I don’t think you have a "bad" male or that you messed up. It sounds like your female is playing hard to get right now and your male is doing his best to impress her by performing vigorous pouch displays. That’s normal behavior and suggests to me that, while your stallion is certainly not pregnant at this time, he is trying very hard to get himself that way. He is doing his best to persuade your female to give her eggs to him. The type of courtship that is going on between your pair is a sure sign of healthy seahorses with an active interest in breeding, which is not a bad thing at all.
In short, Grant, the contractions you noticed are perfectly normal and indicate a healthy stallion in breeding condition that is performing pouch displays to impress the female and persuade her to mate. This mating ritual 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.
These pouch displays are performed with great vigor, while the brood pouch is fully inflated with water, and can be quite alarming the first time you see them. It looks almost as if the male is performing abdominal crunches or experiencing severe abdominal cramps. With it’s abdomen grossly distended, swollen up like a balloon ready to burst, the male’s contortions make it look very much as if it’s suffering from a severe bellyache, but he is actually in perfect health and putting on a performance for the benefit of the female.
Not to worry, sir, the contractions are actually signs of a normal, happy seahorse with a healthy interest in sex! In other words, Grant, your seahorses are doing some serious courting right now.
Here is an excerpt from my new book (Complete Guide to Greater Seahorses in the Aquarium, unpublished) that describes the pouch displays of courting stallions in more detail:
Pouch Displays: 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.
The energetic pumping also helps prepare the male’s brood pouch for pregnancy. It flushes and cleanses out the interior of the marsupium, helps increase the blood supply to the lining of the pouch, and expands the elastic pouch to its fullest extent, in order to prepare it to receive a new batch of eggs. This flushing action is also believed to release special chemicals called pheromones and waft them towards the nearby female to stimulate her all the more. The hormone prolactin is probably the most important of these chemical triggers.
Courtship in many temperate and subtemperate seahorses is dominated by such pouch displays. In addition to pumping, these cold-water 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 around 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.
In short, Grant, your seahorses are actively courting and getting ready to breed. If all goes well this time, they may soon present you with a brood of young to raise.
With regard to your green button polyps, it’s quite possible that the zoanthids could be releasing toxins into the tank that are having an adverse impact on the other corals.
As you know, Grant, soft corals such as polyps have very little stinging ability and generally make good choices for a modified reef tank that will include seahorses. Good choices include the zoanthid polyps (genus Zoanthus), which are tolerant of any light level and tolerate a wide range of water currents, meaning they will do well under the relatively low light and moderate water flow conditions that seahorses prefer. They grow very fast and are a great starter coral for beginners.
Equally desirable are the button polyps (genus Palythoa, etc.). They are extremely hardy and are an excellent starter coral. They prefer low to medium water flow, and will tolerate low light levels, making them another good choice for a seahorse setup. They come in a wide variety of colors and are readily available for a modest cost.
Clove Polyps Star Polyps or Daisy polyps (genus Clavularia) are another good choice. They are good starter corals that tolerate most any light level and do well under a variety of water currents. They are extremely hardy and relatively undemanding.
In short, Grant, zooanthids and polyps in general are seahorse-safe and your ponies won’t mind a tank housing several species of polyps. As far as their stings go, zoanthids and other polyps should be perfectly safe for your seahorses. But, as I am sure your already aware, zoos and polyps produce a toxic slime and you’ll want to observe a couple of precautions when you’re handling the zoanthids, placing in your aquarium, or working in the tank. This is what I normally advise hobbyists in that regard, sir:
First of all, zoanthids and other soft corals such as mushrooms may wage border battles if you place them in close proximity to each other (and the zoanthids almost always lose out to the mushrooms in these skirmishes). So be sure to allow adequate space between the colonies.
Secondly, "Zooanthus and Palythoa both contain very toxic chemicals, that can be dangerous to both reef inhabitants and humans. The most well known is Palytoxin, which has been documented as one of the most poisonous marine toxins known (Mereish et al, 1991). Palytoxin can affect the heart, muscles, and nerves leaving its victim in paralysis, and possibly death. Because of the toxin, you should never handle Zoanthus or Palythoa with open wounds, nor should you touch your mouth or eyes after handling the species. (We recommend the use of disposable latex gloves) When propagating either of the species, it is critical to remember that the slightest rub of an itchy eye, or even a small cut from a hang nail, might be enough to land you in the hospital. In the aquarium, some rapid growing Zoanthus colonies can be aggressive to stony and soft corals, but in general, they are very peaceful, and you can slow the growth rate by the controlling the overall nutrient load of your tank."
In general, aquarists need to handle any polyps from the genus Zoanthus and Palythoa with care, Grant. Here’s what James Fatherree advises in that regard:
There are several types of commonly available zoanthids, including all of the palythoans, that can produce a deadly toxin (appropriately called "palytoxin"). It is found is the mucous coat that they cover themselves with, and if you get enough of it in an open wound, or your eye, mouth, etc. – it just might kill you. Many hobbyists have reported cases of numbness, sickness, and/or hallucinations, but the stuff is actually strong enough to kill, as well.
Handling them when you have a wound is an obvious no-no, but when you touch a colony and get the slime on your fingers (which is unavoidable with these things), it is imperative that you don’t rub your eyes, suck your fingers, or even pick your nose until you have washed your hands thoroughly. Really, you should never handle these without wearing protective gloves. Some hobbyists (including me) have handled zoanthids without gloves many, many times in the past, but it is now well-known that things can go very wrong when this is done, even if you have no wounds you know of and plan on washing your hands immediately after touching a specimen.
Wear the gloves! (James W. Fatherree, M.Sc., 2005)
So this is one of those cases when it’s better to be safe than sorry and err on the side of caution. When in doubt, don’t take chances — wear gloves and handle all colonial and button polyps with all due care. I would also wear gloves in any aquarium with bristleworms as a precaution — those spicules can be extremely irritating and bristleworms larger than 2-3 inches are capable of delivering a nasty bite.
So if your green button polyps are dying back, they could indeed be releasing chemicals that are harmful for your other corals, Grant. I would suggest carefully removing the declining colony of green button polyps — wearing gloves, of course, and observing the precautions outlined above — and then performing a water change in conjunction with filtering the aquarium water through fresh activated carbon and/or a Polyfilter Pad, sir. Prepare the fresh saltwater ahead of time so there is no delay in making the water change after you remove the polyps in question.
Best wishes with all your fishes (and invertebrates), Grant. Here’s hoping that your corals are soon back to normal and that your seahorses are successful in completing the egg transfer, resulting in an uneventful pregnancy this time around.
Pete GiwojnaJuly 4, 2008 at 10:56 am #4312BigGrantmanGuest
Thanks for the help. One more question the female isn’t thick. so does she not have eggs is that why she is playing hard to get. How long will this last if she has no eggs. Thanks GrantJuly 4, 2008 at 11:56 pm #4313Pete GiwojnaGuest
How soon your female will be ready to ripen another clutch of eggs depends on when she last mated. If there was a successful egg transfer about two weeks ago, then it may take another week or two before she is ready to mate again. Females normally only ripen one clutch of eggs each breeding cycle, and for Mustangs and Sunbursts (Hippocampus erectus), a mating cycle is typically about one month or a little less.
If there was not an actual mating two weeks ago, and your stallion was simply displaying with a ballooned pouch full of water rather than carrying eggs and developing young, then your female could ripen another clutch of eggs at any time.
Seahorses are fractional spawners and very well adapted for producing clutch after clutch of eggs. Females maintain a spiraling assembly line of developing oocytes (egg cells) at all times, only a portion of which are fully mature and are released at each mating (Vincent, 1990). This differs from the reproductive strategy of most fishes, which are multiple spawners that release all their eggs each time they mate and then start over, maturing an entirely new clutch of eggs from scratch for the next spawning.
The structure of the ovaries is unique to syngnathids. They are paired organs, which join to form a single oviduct (the seahorse’s version of a Fallopian tube) just before the urogential pore (Vincent, 1990). Oocytes spiral out from the center of each ovary, creating a coiled sheet of developing eggs at differing stages of growth (Vincent, 1990). The earliest or primordial eggs arise from the germinal ridge that runs the entire length of the ovary, and lie at the center of the coil from which they spiral out as they develop so that the fully mature eggs are the furthest from the center of rotation (Vincent, 1990). Roughly 20-25% of the outermost eggs in this ovarian assembly line are mature, ready to be discharged during ovulation and deposited with the male (Vincent, 1990). Thus, fully 70-75% of the female’s developing eggs are retained in the ovaries after mating, so a new clutch of eggs will mature relatively quickly and lie in readiness for the next mating cycle.
Seahorse ovaries are always active, busy creating and developing new eggs (oogenesis), forming the yolk (vitellogenesis), and resorbing any mature ova (atresia) leftover after mating or at the end of the breeding season (Vincent, 1990). Eggs in all 4 stages of development can be found in the ovaries throughout the year.
So if your female has not mated recently, Grant, her ovarian assembly line has mature eggs ready and waiting right now and she could hydrate them and mate successfully at any point — today, tomorrow, even right at this moment. But if your pair of seahorses did indeed mate two weeks ago, she will need another week or two for the outermost eggs in the queue to mature fully before she can mate again.
Best wishes with all your fishes, Grant! Here’s hoping that your new seahorses produce a healthy brood of young for you very soon.
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