removing male before delivery

Dear Michelle:

Congratulations on your impending brood of Brazilian seahorse babies! You’re quite correct — the gestation period for Hippocampus reidi is typically right about 14 days at standard aquarium temperatures, so your male should be due any time now.

I would not recommend transferring the pregnant male to a nursery tank, Michelle. You never want to handle a gravid male unnecessarily late in his pregnancy, nor is it advisable to separate a pregnant male from his mate. I would allow the gravid male to give birth in the main tank where he is right at home, alongside his mate, and then transfer the newborns to your nursery tank, being careful not to expose the newborns to the air at any time during this process.

This is what I normally advise home hobbyists with regard to using an "paternity tank" for pregnant males:

<open quote>
Whether to allow the pregnant male to give birth in the main tank and then to transfer the fry to the waiting nursery, or to transfer the expectant father to the nursery tank ahead of time so he can delivery his brood there is a very important decision. There are two schools of thought on this issue. Some hobbyists feel it’s best to use the nursery tank as a paternity ward, since the delicate newborns never need to be handled if the male gives birth directly in the nursery. Other breeders feel it’s better to disturb the pregnant male as little as possible and prefer to have him deliver his brood right where he is, in the familiar surroundings in which he’s most comfortable.

That’s a no-brainer. In my opinion, it’s ALWAYS better to assure the well being of the male and safeguard your broodstock. A pair-bonded couple will soon establish a regular breeding cycle in the aquarium, producing a new brood every two, four, or six weeks. (The gestation period varies with the species and is often correlated with the lunar cycle so that the fry are delivered during the highest tides, which helps disperse the young; Vincent, 1990.) A healthy pair-bonded male will deliver a new brood of young every month or so during the breeding season, producing countless offspring over the course of its life. But if you lose a breeding male, you lose all of his future progeny with him, as well as the superior genetic traits he carries. It is folly to jeopardize the health of a pregnant male for the sake of the brood he is carrying at the moment.

Handling a gravid male, especially when the pregnancy is well advanced, should be avoided at all costs. At best, it will be stressful for the male to be captured, separated from its mate, and transferred to a strange new environment (Giwojna and Cozzi-Schmarr, Feb. 2002). At worst, rough handling and stress can trigger premature delivery or cause the pregnancy to be aborted altogether, adversely affecting the health of the male and his brood (Giwojna and Cozzi-Schmarr, Feb. 2002). Stressing a pregnant seahorse has many detrimental effects, including decreased appetite, adverse hormonal changes, impairing the immune response and lowering disease resistance.

Separating the expectant father from his mate at this crucial time can also prevent him from re-mating with his chosen partner and may even break up a pair-bonded couple (Giwojna and Cozzi-Schmarr, Feb. 2002). Throughout his pregnancy, the male maintains daily greeting rituals with his mate that serve to strengthen and reinforce their pair bonds and keep them physiologically attuned to one another. When the male gives birth, his mate is normally waiting nearby, ready to hydrate her clutch and rise for the exchange of eggs as soon as he has recovered. Many times they will resume their mating dance and re-mate scant hours after the male delivers his latest brood.

Isolating the male from his partner during the pregnancy effectively puts an end to all of that. They are preventing from conducting morning greetings, their carefully orchestrated breeding cycle may be disrupted as their hormonally regulated reproductive synchrony is lost, and the pair bond is weakened accordingly (Giwojna and Cozzi-Schmarr, Feb. 2002). Their bonding may even be broken as a result. That’s not what a successful breeder should strive for!

If you are concerned about the filtration in your main tank "eating" the newborns, modifying your filter to prevent this is a much better alternative than transferring the male to a paternity ward (Giwojna, Feb. 2002). Just screen off the intakes or cover them with sponge prefilters. Or you can simply switch off the skimmer and any supplemental filter(s) when his due date arrives and delivery is imminent. (Just don’t shut down your primary biofilter!) That way, the male can remain with his partner through the pregnancy and deliver his brood in a stress-free environment.

Here are Carol’s thoughts on the matter:

"As Pete Mentioned, probably the most stressful thing one could do to a pregnant (gravid) male that is close to giving birth would be to "handle" him by moving the male from his normal environment (home!!) to a new and unfamiliar environment like a different holding tank. (hotel room!!). This unnecessary "transfer" and " handling" will force him to adapt to a strange environment causing a general increase in his stress level causing many possible negative outcomes such as decrease in appetite, lowering of the immune system causing opportunistic pathogens currently present in the aquarium but not at high levels to take a hold on the sea horse causing health problems, and sadly may prevent him from re mating with his mate.

You see, the male will continue his bonding rituals (such as Pete has described) with his mate during the birthing process and immediately after giving birth. The pair will begin the treasured mating dance that will hopefully result in a successful egg transfer from the female to the male often within hours after giving birth!! Remember that with many sea horse types the older the male the larger the size of his pouch and therefore the greater the number of sea horse babies in the pouch!! For example, a 5 year old adult H.reidi male may give birth to as many as 2000 babies with each spawn!!!! A young 6 month old juvenile male may only give birth to 10 or 20 babies!!! It is also more likely that the older male has been mating with the same female all is life!! Imagine the stress of not being with his " beloved" during this time!

This unnecessary "handling" or "transfer" is, of course, extremely hard on wild caught males and may cause his death immediately after giving birth. One should avoid purchasing wild caught pregnant males at all costs. It is easy to feel sorry for him in the pet store, but his purchase only encourages the collectors to take additional pregnant males the next time causing further devastation to the already highly threatened wild sea horse populations.

Certainly this "handling" or "transfer" stress is greatly reduced with the farm raised pregnant males but the general concept still applies. If you purchase a farm raised pregnant male you should not expect a male that is almost ready to give birth but one that is within 2 weeks of giving birth. The normal gestation period averages at 30 days depending mostly on species and environmental parameters such as temperature and diet.

If these 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 pregnant

If , however, you are able to keep these parameters optimum, you will have a much greater chance of being successful with your pregnant male so that you can enjoy this amazing phenomena of the pregnant male sea horse!! With a little more patience you will surely be rewarded with the great performance of the sea horse mating dance followed by the most precious site of all……the fat bellied pregnant male sea horse!!!"

Aloha, Carol Cozzi-Schmar
<close quote>

Generally, Michelle, the only time a paternity tank is advisable is on those rare occasions when a pregnant male develops a health problem that requires treatment (Giwojna, Feb. 2002). In that case, it’s best to make the transfer early in his pregnancy (at least 2 weeks prior to his delivery date). Make sure the hospital tank/paternity ward has been prefilled with water from the main tank to reduce stress and ease the transition. If at all possible, transfer his mate along with him. And situate the paternity tank in a quiet, low traffic area, making certain it includes enough shelter so that the expectant father won’t feel vulnerable and exposed.

Best of luck with your pregnant H. reidi, Michelle! Here’s hoping he delivers a healthy brood of Thanksgiving babies and proves to be a prolific breeder from now on.

Respectfully,
Pete Giwojna

Dear Michelle:

Congratulations on your prolific pair of Brazilian seahorses (Hippocampus reidi)!

Yes, it is true that gradually reducing the water temperature will extend the gestation period for your seahorses and, if I was you, Michelle, I would concentrate on two main things to increase the survivorship of your H. reidi fry: (1) providing your breeding male and female — your all-important broodstock — with the very best possible nutrition, and (2) reducing the water temperature in your H. reidi tank somewhat in order to prolong the gestation period of your stallion. We now have considerable evidence that providing the male and female with a very nutritious diet results in a larger average size for the newborns, which enjoy increased survivorship/lower mortality rates as a result. Jorge Gomezjurado found that providing his H. reidi and H. ingens broodstock with a very nutritious diet increased the size of the newborns to the point that they could accept newly hatched brine shrimp for their first food. So I would give your breeding male and female a steady diet of Piscine Energetics frozen Mysis relicta enriched with lipid-rich Vibrance 1, and then provide them with regular feedings of enriched live foods as well.

As far as reducing the water temperature, as you know, the lower the water temperature, the longer the gestation period in Hippocampus. And a prolonged pregnancy does indeed have benefits for the developing young. For example, the Birch Aquarium at the Scripps Institute of Oceanography finds that maintaining locally obtained H. ingens at cooler water temperatures extends the gestation of gravid males and increases survivorship of their pelagic fry (Liisa Coit, pers. com.). Lowering the water temperature, hence prolonging the gestation, increases the incubation period for the fetal fry and embryonic young the gravid male is carrying, which in turn translates into larger, more developed fry. The bigger, better developed newborns that result can feed and swim more efficiently and their survival rates are increased accordingly (Liisa Coit, pers. com.). So I would keep the water temperature in the comfort range for your H. reidi, but at the lower end of the range rather than the upper end of the range. They typically do best between 72°F-78°F, so try gradually reducing your water temperature to see if that produces the desired results. Normally, H. reidi give birth after a brief 14 day gestation period, and if you can extend that for just a few days by manipulating the water temperature, it can make a big difference.

Try to reduce the water temperature in the main tank gradually, no more than 2°F per day, and see if you could stabilize the temperature at around 70°F. That may require an aquarium chiller, but lowering the water temperature several degrees should certainly increase the gestation period for your prolific ponies and produce larger newborns with a better chance of survival.

Best of luck raising this most challenging species, Michelle! If you contact me off list ([email protected]), I can provide you with some additional tips and suggestions for raising H. reidi fry.

Happy Trails!
Pete Giwojna