For young born greater than 1.0 cm (0.4"), newly hatched Artemia nauplii are a basic food which should be supplemented by other plankton. Artemia nauplii seem to allow growth and survival for at least six weeks. After that, the food source may be too imbalanced. The Wilhelmer Aquarium has found that seahorses don't flourish on Artemia alone, partly because the young seahorses find Artemia difficult to digest.
The young should never be totally without Artemia nauplii. Avoid brine shrimp shells as these are sharp and can kill young seahorses. At first, two liters of Artemia hatchlings in water may suffice but the young seahorses will soon require that amount three times a day.
A more reliable way to feed seahorse young is more complicated but the Berlin Aquarium manages about 85% survival this way, with the help of a full-time technician!
1. To culture algae: Set up a tank with double salinity saltwater to prevent growth of plankton. Then add Dunaliella algae. A starter culture can be obtain commercially (Florida Aqua Farms, Dade City, Florida) or you may be lucky enough to get it from a public aquarium or botanical institute. Then, for each 70 liters of algae culture, add 5 ml Wuxal plant fertilizer weekly -- roughly 1 ml of fertilizer per 4 gallons of culture. (Wuxal is similar to Microalgae Grow® from Florida Aqua Farms). Maintain the culture in constant light (normal white) with aeration. Clean the tanks regularly. It is safer to have at least two algae tanks going at once; one which is developing and one from which you take algae to feed plankton. It takes about 1-2 weeks to grow algae. When the algae tanks are dark green, then transfer algae water to the zooplankton tank.
2. To feed the algae to zooplankton: To start the culture, buy plankton or use water from the ocean or in which fish are imported as a starter. The tank should be lit 24 hours a day with white light. Use the same salinity water as for the young seahorses. The algae water will have to be mixed with fresh water to dilute it. Add more algae to the plankton tank whenever the water is clear. Take any accumulated sediment on the bottom of the plankton tank out before feeding the zooplankton with more algae, strain it and feed it to the zooplankton again. Add about 7 liters of algae for each 50 liters of zooplankton (roughly 1.5 gallons of algae per 10 gallons of zooplankton) every ten days or so. Retain enough algae culture to restart a new algae culture.
3. To feed zooplankton to baby seahorses: Young seahorses don't need to be feed the first day after birth. After that, use two plankton nets of zooplankton 5-7 times daily (whenever no plankton is visible in the rearing tank) AND have a drip of diluted plankton going at a rate of 10 liters per 24 hours. The drip can be from a bucket on top of the tank with an airhose siphon (with valve controlling flow).
4. Switch to Artemia After 10 days to 2 weeks, start the young on Artemia nauplii Give them about 5 nauplii per seahorse per feeding and scatter them widely rather than clumping them. You can also give them small Daphnia as they grow. Keep feeding the young with zooplankton as well for about 3-4 weeks. Feed 5-7 times daily for about 6 months until the young are 4 cm (1.5") long.
This page last updated on April 8, 1998.
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