June 21st, 2008 Posted in Fish | No Comments »
Rynnie Henderson
The intent of my experiment is to determine the effectiveness of using an alternative to live algae when raising red drum larvae. I set red drum eggs in my 150 liter cone tanks Thursday night, and the larvae are still looking healthy and, most importantly, alive. I will allow them to grow for three days before starting their feeding regime. On the day I start feeding, I will also begin the four treatments.
We are attempting to determine whether or not using live algae with larval fish can be replaced with a green dye or another cheaper, faster substitute. Past studies have shown that when live algae is grown in the tanks with the larvae, the growth rate and survivability of the larvae are greatly improved. As of now, it is unclear exactly why the algae is so beneficial. The algae most likely help maintain rotifer enrichment in the water column (rotifers are tiny organisms often fed to larval fish), but there appears to be little nutritional contribution from the algae directly to the fish. Some researchers speculate that the algae provide contrast for the larvae so they can more easily locate and retrieve prey. If this is the case, a green dye would have similar beneficial results to algae.
This experiment will compare the results of using Isochrysis galbana (a live algae), Chroma (a green dye), Sanolife (a manufactured algae substitute), and clear seawater (as a control) in the water with the red drum larvae. We will examine the growth rates, survival, and trypsin levels to monitor the effectiveness of each treatment. If the alternatives to live algae prove to be just as beneficial, tremendous time and money can be saved in red drum aquaculture and could possibly be used with many other fishery raised fish.