DESIGN OF AN EGG COLLECTION SYSTEM FOR A PUBLIC AQUARIUM: A RESOURCE FOR FISH CULTURE

Public aquariums provide an unparalleled resource for a large and diverse array of ornamental species. Spawning of these captive populations often occurs volitionally as exhibits possess mature, well-fed specimens that have had an ample amount of time to acclimate to life in captivity. Often these individuals spawn frequently and are able to supply a reliable source of eggs and larvae that can be utilized for research and fish culture. In addition, the nature of these large exhibits enables egg collection from species that may be unfeasible to house in traditional laboratory or small-scale fish culture facilities.

Built in the early 1930s, the Key West Aquarium is one of Florida's oldest aquariums. It was the first aquarium to use an "open air concept," which allowed for natural sunlight to illuminate the concrete marine displays. In the 1960s a roof was added to the once opened-air aquarium to cut down on algae in the exhibits. Today the Aquarium stands as one of the top attractions in Key West and is home to sharks, turtles, stingrays, tropical fish, and various other local species.

As the culminating experience of my Tropical Ornamental Mariculture Technician program at Florida Keys Community College, I engaged in an internship at the Key West Aquarium that provided me the opportunity to research and develop two different egg collectors designed specifically for tank systems of the historic aquarium.

The first egg collection design was a basket made out of a small 1-gallon bucket cut open and covered with mesh on all sides. It was then placed in a 1½-gallon bucket with a small hole drilled in the side. The collector was placed at the back side of the overflow on a flow-through, native species system that receives a constant supply of seawater from a saltwater well. After water passes through the egg collector, it flows out a hole cut in the back of the tank and overflows into a common drain trough.

A second egg collection design retrofitted acrylic tanks that are set into the old concrete cells of the original marine displays. These tanks contain standard weir overflow boxes in which egg collectors were fitted inside.

All egg collectors were checked daily and emptied as necessary.  

We succeeded in collecting a large amount of fish eggs via these collectors. Eggs collected from the basket-style collector were incubated in 10-gallon glass aquaria using the standard greenwater technique. Rotifers were provided as feed. Larvae were maintained for up to 5 weeks and were suspected to be some species of grunt.  

Efforts are ongoing to collect and rear eggs from the ornamental fish species housed at The Key West Aquarium. Future work will entail transferring a subset of eggs to Florida Keys Community College for rearing by students of the Tropical Ornamental Mariculture Technician program.