- This topic has 2 replies, 3 voices, and was last updated 16 years, 6 months ago by Pete Giwojna.
March 27, 2007 at 5:09 pm #1171carrieincoloradoMember
I have only 4 fry left from my brood that were born in early November. (started with 47) I thought that once they were eating mysis I would be home free, but the hydroid outbreak saw some of them stop eating last month and I lost a couple more for no reason. They looked fat and happy, and then they were dead. Two out of the four left tend to float sideways on the top of the water. They share a tank with the Pixies, so there is also brine to eat twice a day, and I shave mysis twice a day for the remaining four erectus. I do a 20-50% water change once a week. Any advice would be great. My adult erectus have been courting, but I think the flow might be too high in the tank for a successful egg exchange. I haven\’t seen any real attempts, though, or dropped eggs. And since I apparently really suck at raising the fry, perhaps it\’s for the best!March 27, 2007 at 9:37 pm #3514SuzanneGuest
Don’t be discouraged. I know it is heart-breaking to get them so far and then have them expire, but you learn from each attempt so you have gained something very valuable.
I have the new Seio pumps on my pony tank. They have a good flow but it is more dispersed and mellower flow. You might try pointing your flow towards the front glass or a large rock to slow the pressure of the water?
Wait ’till the experts come to help? You are not doing anything wrong, you are just learning. The hard part of SW fish breeding is that we are the pioneers!March 28, 2007 at 8:20 am #3519Pete GiwojnaGuest
I agree with Suzanne — I don’t think you’re necessarily doing anything wrong at all. Quite the contrary, you must be doing a lot of things right when it comes to rearing your fry. It is very common — almost the rule — for home hobbyists to lose the entire brood during their first few attempts at rearing. You have managed to raise almost 1/12 of your brood well into the juvenile stage, and four of those youngsters are almost at the five month old mark. And it sounds like your results would have been even better if it hadn’t been for that outbreak of hydroids. That is not bad at all for a home breeder!
So don’t be discouraged. As you refine your methods and become more proficient at providing suitable live foods for the newborns and work out the feeding regimen that’s most efficient for your particular circumstances, your results will get better. One suggestion I can make in that regard is to try providing your newborns with copepods for the first week or so to get them off to a good head start, as discussed below.
Copepods are the ideal first food for H. erectus and other pelagic seahorse fry. Research indicates that newborn H. erectus fed with live copepods for the first 4-5 days of life have markedly increased survival rates compared to newborns that receive Artemia nauplii as their first foods (Gardner, 2002). This is because the copepods have a much superior nutritional profile with much higher levels of highly unsaturated fatty acids and are a natural prey item that seahorse fry can digest much more easily than Artemia (Gardner, 2002; Payne, 2000; James, 1998). Studies indicate that copepods comprise a large percentage of the diet of seahorse fry in the wild, and they are therefore very well adapted for digesting such prey. Newborns have a much more difficult time digesting Artemia (Warland, pers. com.), which is removed from the marine environment and ocean food chains by several million years of evolution (Gardner, 2002).
The problem with relying on copepods as the first food for seahorses is that the pods are much more difficult to culture and provide it large quantities then Artemia nauplii. Fortunately, this is not an insurmountable obstacle, since they only need to be provided for the first four or five days of the newborns life. The superior nutrition provided by the copepods gets the newborns off to a great head start and allows time for their delicate gastrointestinal tract to develop and mature. As a result, after four or five days of growth and development feeding on lipid-rich copepods, the H. erectus fry are then able to digest Artemia much more efficiently and can thrive on a staple diet of newly-hatched brine from there on in.
You are correct that the older the fry become, the better their chances generally are and the lower their mortality rates tend to be. Survivorship improves significantly once the newborns make it past the high-risk pelagic phase of life, and there is another market increase in survivorship once the juveniles are successfully weaned onto frozen foods. It’s unusual for juveniles the age of yours to develop buoyancy problems, which are most often due to the fry accidentally ingesting air. You could try pressurizing the two juveniles that tend to float sideways at the top in a flow-through container at a depth of about 40 inches. The increased hydrostatic pressure at that depth may help restore them to neutral buoyancy again.
If you look up Don’s message titled "Sick seahorse: floating" on this forum, you’ll find complete instructions for pressurizing a seahorse in a homemade decompression chamber in case you want to give it a try, Carrie. You can find the discussion at the following URL:
Best of luck raising your juveniles to maturity, Carrie!
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