Food can be offered within the first few hours of life, but is not essential until after about 6-10 hours.  Remember they have just been born and their digestive tract is very immature.  It can take several days for them to be eating at the full rate.

Baby seahorse fry can consume vast numbers of hatched Instar II Artemia (Brine Shrimp) for large fry-10 mm onwards. Rotifers or Copepods will need to be offered to some smaller fry <10 mm.  All foods for fry should be enriched.  Foods high in fat content are essential.  Various enrichments are available Selco^®, algae pastes etc.

The main causes of fry death are:

• Air intake

  The food source, baby brine shrimp are light sensitive.  The food tends to swim at the surface of the water, young fry can intake air with their food and cannot dispel this air.

  Their equilibrium is upset and they will float sideways on the surface of the water.  A bubble can be spotted just below the head.  Unfortunately once air is inhaled there is very little you can do to save them.

  This is however, avoidable.  You can darken off the top and sides of your nursery tank and apply lighting to the side of the tank encouraging your fry to eat their food below the surface of the water.

  
  The diagram above is an example of a fry-rearing tank (20 litres/5 US gallon).  This type of tank set-up lessens the risk of air intake during feeding.

• Starvation

  Starvation can be caused both by not adding enough food and by over feeding. Each baby seahorses can eat 2,000 newly hatched brine shrimp a day.  Food should be added to your nursery tank at least three times per day.

  You need to add enough food for your fry to eat for about 15-20 minutes (75% of the food should have been consumed).  If it is not then you have added too much.  They then should have some time to digest this food, about 3 hours is plenty.  Only feed during daylight hours and turn off lights at night.

  The main mission in a baby seahorse's life is to consume food.  If you keep the tank stocked continually with too much food the seahorse will continue to eat non-stop.  As well as being tiring for the fry, the food is not kept in the intestinal tract long enough to get any of the nutritional benefit.

• Poor Water Quality and Water Movement

  Because the stocking density of your nursery tank is high and you are continually adding foods with high fat contents to enhance growth, the water quality can deteriorate very quickly.  Fry can be very susceptible to bacterial infections. It is vital to rinse all food sources with clean seawater through a fine mesh net before adding them to the tank. Bacteria thrive in artemia growing tanks and a rinse will ensure dilution or elimination of bacteria.

  By doing regular water changes at least daily (15-30%) and keeping the tank clean of debris you can minimise the chances of bacteria building up.  It is advisable to keep the nursery tank free of any gravel or sand, as a bare bottom tanks are easier to siphon.

  Adequate hitching posts need to be supplied for rest times.

  Water flow can be critical.  There needs to be enough water movement to keep the food moving past the seahorses, enough to keep the seahorses moving, but not too much to cause them to tire easily or not be able to hitch when needed.

  The idea is for the young seahorses to build up lots of fat and a small amount of muscle.  If the water is too fast the seahorse fry spend all their energy hanging on to the hitching posts.

  As previously mentioned stocking densities in fry tanks are usually high, so it is important to ensure that adequate air is supplied.

  Although not necessary, a sponge filter can be added to the nursery tank to aid in water quality.  This filter will need to be turned off during feed times because all the food can be sucked into the filter.

  When you notice your male seahorse is pregnant you can add a small sponge filter to your main tank, beneficial bacteria will cling to this sponge and when your fry are born you will have an active biofilter.