Nursery Tank Question

Dear Joe:

I’m sorry to hear that your seahorse fry didn’t fare better, sir, but that’s not unusual. There is a always a steep learning curve when it comes to rearing the newborns, and it’s quite common — perhaps even the rule — for the home breeder to lose the entire brood during his first few attempts at rearing. But 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. You will have more of the fry surviving for longer periods, until I eventually you are able to raise a few of the fry from a few of the broods to maturity. It’s just a matter of patience and hard work, Joe — there simply are not a lot of shortcuts that are helpful when you’re trying to raise baby seahorses.

I agree that feeding issues may have been the root of the problem you had with the first brood of fry, which most likely experienced a very high mortality rate due to malnutrition. I suspect the Zooplankton Mix may represent a shortcut that’s actually more trouble than it’s worth. I just don’t see the Zooplankton Mix being able to provide the quantities of free-swimming larval organisms of the right size for the baby seahorses that are required on a daily basis. At best, they might provide a supplement to their diet and a little more diversity to what they are eating. In all probability, you are still going to need to provide the babies with a staple diet of newly-hatched brine shrimp for the first several weeks of their lives. The Zooplankton Mix is more useful as a starter culture for seeding aquariums with microfauna then as a sustain food source for the seahorses.

I would recommend providing the newborns with 3-5 feedings of newly-hatched Artemia spaced 2-3 hours apart for best results. If you search this forum for the phrase "fry feeding schedule," you’ll find a lot of additional information regarding successful feeding regimens for keeping up with the voracious appetites of seahorse fry.

Here are the instructions for enriching brine shrimp of all ages using the original Vibrance:

Enriching Artemia with Vibrance I

For enriching or "gut packing" live Artemia (brine shrimp), or other live shrimp or live food of all sizes. Blend 1 teaspoon of Vibrance into 1 cup of water for 3 minutes. Add this to the live food vessel for 30 minutes, or until you see the gut of the animal turn red. Rinse the animals with clean salt water and feed immediately to your seahorses or other fish.

As you can see, Joe, the brine shrimp will change color, turning reddish as they absorb or ingest the Vibrance. That’s normal; that’s what you want to see and indicates that the gutloading has been successful. But the enriched brine shrimp shouldn’t stop moving or swimming or lay motionless on bottom. That suggests that something stressed out and killed or incapacitated the Artemia when you were gutloading them. This can sometimes happen if you used too much of an enrichment product, fouling the water, or if the brine shrimp were exposed to temperature extremes, low oxygen levels in the enrichment container, or tap water that wasn’t detoxified. With a little practice, you’ll soon get the hang of gutloading and enriching the Artemia.

Yes, sir, I can for see one or two potential problems with the built-in filtration on your eclipse-style nursery tank. One potential problems is that if the filter draws too much water through the porous sponge, it is going to filter out the newly hatched brine shrimp before the seahorse fry have a chance to benefit from it, and the feeble swimming newborns may also be sucked up against the sponge filter. (Air-operated sponge filters are sometimes employed on nursery tanks, but hobbyists who use them prevent these sorts of problems by opening gang valves to adjust the air stream through the sponge filters to a trickle that doesn’t generate too much suction.) I can envision a scenario in which the filter on the eclipse tank is "eating" more of the newly hatched brine shrimp than the seahorse fry are getting. Not only will that be very wasteful, and detrimental to the newborns by depriving them of much of their live prey, but it will also degrade the water quality in the nursery quite rapidly.

The other potential problem I can foresee with that arrangement is that the porous sponge may require the pump in the eclipse filter to work harder than normal, causing problems with overheating. Because of their hoods, which tend to trap heat produced by the aquarium filter and lights under the best of circumstances, Equips tanks tend to run on the warm side anyway, and any additional overheating is going to be very problematic for the new seahorses and leave them vulnerable to tail rot and bacterial infections.

I would suggest that you try a kriesel or pseudokreisel nursery tank for pelagic Mustang and Sunburst (Hippocampus erectus) fry, Joe. Search the forum for "kriesel" and/or "pseudokreisel," and you’ll find discussions that describe many different designs for more sophisticated nursery tanks that will help boost your survival rates and work better than the modified Eclipse tank you are currently using as a nursery.

Best of luck with your next brood of seahorse fry, Joe! I’m sure you’ll do better next time around.

Respectfully,
Pete Giwojna