Increasing Production of
Copepod Nauplii in a Brown-Water Zooplankton Culture with Supplemental
Feeding and Increased Harvest Levels
J.T. Lemus, J.T. Ogle, J.M. Lotz-2004
North American Journal of Aquaculture, 66(3):
169–176
Abstract:
Two experiments were performed to investigate
increasing the number of copepod nauplii obtained from a brown-water
zooplankton culture for feeding to larval red snapper Lutjanus
campechanus. Brown-water zooplankton cultures rely on the regular
exchange of (brown) estuarine water to nourish and harvest the copepods. The
majority of copepods in both experiments were Acartia tonsa. The goal
of the first experiment was to determine whether adding rice bran to a
brown-water zooplankton culture would increase copepod density. Brown-water
zooplankton cultures supplemented with rice bran had significantly higher
naupliar densities than either brown-water zooplankton cultures without rice
bran or zooplankton cultures supplemented with rice bran but without
brown-water exchanges. Both the rice-bran-supplemented brown-water
zooplankton culture and the rice bran zooplankton culture had higher
copepodid densities than the brown-water zooplankton culture, but they were
not different from each other. The goal of the second experiment was to
determine the harvest rate (25, 50, and 75% of the water volume every other
day) that would produce the most copepods. Copepod densities increased with
a decrease in harvest rate; however, naupliar yields increased with
increasing harvest rate. Copepod populations subjected to the various
harvest rates appeared to undergo similar dynamics and were thus equally
sustainable. There were significantly more nauplii harvested with the 75%
harvest rate than with the other rates, but there was no difference in the
number of harvested copepodids resulting from the different harvest rates.
Naupliar yields of brown-water zooplankton cultures may be increased by rice
bran supplementation and harvesting 75% of the culture volume every other
day.
(University of Southern Mississippi, College of
Marine Sciences, Gulf Coast Research Laboratory, Post Office Box 7000, Ocean
Springs, Mississippi 39566, USA)