Tuesday, July 29, 2014

Does the Aquarium Raise Fish?

The NC Aquarium at Fort Fisher is home to thousands of fish and many people wonder where they all come from. There are many different ways the Husbandry staff populates exhibits. We are often asked if we raise our own fish, and the answer is yes. Fort Fisher staff is researching and working on new ways to grow fish from egg to adult within the Aquarium.

While on exhibit, animals ideally show natural behaviors which often involve laying eggs. There are three main ways fish reproduce. Some fish are bearers, when one parent internally carries the eggs through development. Others are demersal spawners, laying eggs in a nest and guarding them until they hatch.  Lastly, pelagic spawners release millions of eggs to be fertilized as they flow though the ocean. Many aquariums, including Fort Fisher, have succeeded in raising the larvae and fry (baby fish) from bearers and demersal spawners, like our amazing seahorses, small neon gobies and stingrays. However, the majority of Aquarium fish are pelagic spawners. There are many opportunities to raise fish going (literally) down the drain.

Recently, we began a project to collect and raise some of these free-floating eggs. The healthy, fertilized eggs float to the top of the water. Specially built collecting equipment skims the top layer of water, collecting hundreds, and sometimes thousands, of eggs.

Larval rearing system at NCAFF
Pelagic eggs hatch within 24 hours from being released. When the eggs hatch, the larvae are very small and undeveloped.  A special holding tank was developed to keep them gently moving as if in the ocean currents. Initially, there is no need to be concerned about food because the larvae have no mouths. Instead, they feed from an attached yolk for the first few days. When they begin eating, things get a little tricky. Fish larvae are picky eaters. The food has to be the right type, size, and even speed for them to go after it. They survive mostly on algae and copepods (tiny crustaceans).

Juvenile blue striped grunt from eggs collected in April

It takes a lot of trial and error to hatch and grow the pelagic eggs. So far, the Fort Fisher Husbandry staff has had success with blue striped grunt; collecting eggs from our largest exhibit, the Cape Fear Shoals, and raising the fish behind the scenes. We have collected many types of eggs from the Shoals and other exhibits. Each attempt moves us closer to a goal of raising more fish in a sustainable way at the Aquarium. 

1 comment:

  1. Thanks for great information you write it very clean. I am very lucky to get this tips from you.

    Fish aquarium home products


Don't worry! Your comment will appear shortly.