FusedJaw: Seahorses, Pipefish & Seadragons

Acclimation

A long acclimation period is recommended when introducing new Leafy seadragons to their exhibit or holding system. Often, if transported from Australia, the fish have been in bags for more than 36 hours, and their water quality and water temperature may be drastically different from the aquarium into which they will be moved. It is not uncommon to have to overcome salinity differences of several points and temperature differences of several degrees.

At The Dallas World Aquarium, our normal acclimating procedure is to trickle water slowly into the transport bags from the exhibit through a small diameter airline tubing that can be “tied closed” to slow down the flow when the temperature, pH, or salinity differences are great. This procedure normally takes from one to three hours. The animals are not transferred into the exhibit until salinity, pH and temperature match exactly.

It is recommended that the “night light” be the only light on in the exhibit when the seadragons are transferred into it. The lights can be turned on gradually after the fish have had a chance to adjust to their new surroundings. The use of a net on the seadragons is discouraged, especially when removing them from the water during transfer into the aquarium. Use of a glass Pyrex bowl or a small bucket is recommended to avoid lifting the snout or gills of the seadragon from the water. It is best if the seadragon remains completely submerged during the transfer. The use of a bowl or bucket also reduces the risk of damage to the fish from getting tangled in the net by their leafy appendages.

In addition, it can be useful to cover the sides of the holding aquarium if it is an area frequented by aquarium staff. This allows the dragons to “settle in” and adjust to their new surroundings without becoming “spooked”.

Feeding and Nutrition

Perhaps the single most important factor in successfully keeping the Leafy seadragon in a controlled environment is the feeding routine. Leafy seadragons were originally believed to be difficult to feed, and prefer live food, specifically mysid shrimp. Obtaining sufficient shrimp to sustain a collection of seadragons, can be very expensive, and culturing them, in addition to the expense, can be very time consuming. At The Dallas World Aquarium, we have tried both methods. At present, we are receiving weekly shipments of 40,000 live Mysidopsis bahia, mysid shrimp. These are wild caught in Florida waters. In addition, we have the option to purchase live cultured mysid shrimp from a toxicology lab in the Dallas area. A backup source for the mysid shrimp is very important. The Leafy seadragon cannot go for extended periods of time without food. The adults on exhibit are fed thoroughly twice per week with the live mysid shrimp. The smaller, younger seadragons are fed mysids three times per week. Before each feeding, the mysid shrimp are fed Artemia sp., brine shrimp nauplii that have been soaked in a nutrient rich supplement known as SELCO for 24 hours. These normally warm water shrimp are then acclimated to the cold water of the exhibit.

Many institutions feed frozen mysis shrimp as the main food source (1-3 times per day) or as a supplemental food source for their dragons. Usually these are freshwater Mysis relicta, and are often readily accepted by seadragons, usually young dragons. It is best when planning to feed frozen mysis to offer it to the dragons when they are young (and large enough to eat the frozen mysis which can be quite large compared to live). Every institution tries a little something different in terms of feeding techniques, but the key in the beginning seems to be keeping the mysis suspended so that they look like they are swimming. Eventually, if the dragons accept the frozen mysis, they will learn to pick them up from the bottom.

It should be noted that Leafy seadragons successfully weaned onto frozen mysis shrimp can change their preference without notice. This change can happen for no apparent reason, and has been observed after moving young dragons from quarantine or holding areas the exhibit (Nero 2005). It is always best to have access to a supply of live mysids in the event the dragons choose to refuse the frozen variety.

Two sources for quality frozen Mysis relicta are Gamma frozen foods and Piscene Energetics.

Many institutions choose to culture live mysid shrimp to meet the needs of their seadragons. The Toledo Zoo has a successful program for culturing live mysid shrimp, and at one point was feeding their dragons exclusively cultured mysids.( Hemdal, 1999)

The Waikiki Aquarium reports that they feed their dragons live Penaid shrimp, Penaeus vandemai (Delbeek 2000).

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This entry was posted on Friday, May 29th, 2009 at 7:00 am and is filed under Advanced Care. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.