Just about 25 days ago Paul Rinehart and Ramon Villaverde of the Columbus Zoo and Aquarium diligently cleaned and separated a few thousand pelagic eggs collected from their Discovery Reef Exhibit. After transferring the eggs into clean, filtered seawater they were packed and shipped to Florida. Today, 19 of those eggs are still alive – though they have taken on a drastically different appearance.
|One of 19 juvenile Pomacanthus sp. raised at the Tropical Aquaculture Lab. At 25 days after hatching, its identity is unclear.|
The confusion is mounting as to whether we have raised Pomacanthus annularis or a hybrid between P. semicircularis x P. annularis. We know that we have raised P. semicircularis based on DNA analysis, but the jury is still out on 5 or 6 smaller, more vibrant members of the first cohort.
In the latest shipment from the Columbus Zoo 19 angelfish appeared. When the eggs arrived we split the eggs into two tanks. One, a 140 gallon tank, and the other, a 50 gallon tank. Within each tank variation of growth and pattern was apparent early on. Between the tanks, growth and pattern is astounding. In the larger tank, the fish grew fast and striped up at less than 20 days. The ones in the smaller tank are just now starting to show their stripes. The environmental conditions provided in the larger tank seemed to increase growth rates, but what about differences in growth within the tank. Is this just species variation as would be expected or is it, yet again, adding to the confusion of species identification.
Matthew L. Wittenrich, PhD
Senior Biological Scientist
Tropical Aquaculture Lab
University of Florida