Author
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Ludwig, Gerald |
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Submitted to: Book of Abstracts World Aquaculture Society
Publication Type: Abstract Only Publication Acceptance Date: 9/1/2002 Publication Date: 2/5/2003 Citation: LUDWIG, G.M. TANK CULTURE OF SUNSHINE BASS MORONE CHRYSOPS X M SAXATILIS FINGERLINGS WITH THREE CONCENTRATIONS OF ROTIFERS AND ARTEMIA NAUPLII.. BOOK OF ABSTRACTS WORLD AQUACULTURE SOCIETY. 2003. 160. Interpretive Summary: Technical Abstract: Sunshine bass Morone chrysops X m. saxatilis fry are obligate zooplankton consumers during their first few weeks of life. When they begin exogenous feeding at age 4 days post hatch they are so small that they can only ingest small small zooplankton such as rotifers. Under natural conditions they soon increase in size and begin to consume larger zooplankton such as copepod nauplii and then older copepods and cladocerans. For tank culture, the brackish water rotifer Brachionus plicatus appears to be a suitable first food. Within a few days the fry may be switched to immature brine shrimp Artemia nauplii and then weaned to artificial prepared feeds by 28 days post hatch. Feeding rates of rotifers and brine shrimp nauplii have not been determined for maximum growth of sunshine bass fry. In this experiment three concentrations of rotifers (5, 10, and 15 per ml) and then three concentrations of Artemia nauplii (1, 1.5 and 2 per ml) were presented to the fry before they were weaned to manufactured feed. The experiment started when fry that were 4 days old and approximately 4.5 mm average total length were stocked into 100 liters of water at 75 fry per liter on May 2, 2002. Three tanks were assigned to each feeding treatment. Water was aerated and had a salinity of 2-7 ppt, prepared by adding an artificial sea salt mixture to fresh water. Each day ¾ of the water was replaced. Each tank had a sponge filter. For the first 4 days only rotifers were fed. Four times each day rotifers were fed at the rate of 5, 10, or 15 per ml. Rotifers for the second two feedings were enriched with Super Selco. From day 5 through day 9 freshly hatched Artemia nauplii were also added to the tanks at the rate of 1, 1.5 and 2 per ml. twice per day. From day 10 through day 12 only Artemia were fed at the same rates three times per day. Starting day 12 a microencapsulated (150-200 µm and later 200-250µm) feed was fed 10 times per day. Tanks were harvested when fry were 28 days post hatch. Mean survival rates were 22.4, 35.3 and 52.9% for the low, medium and high feeding rates respectively. Mean total lengths and weights of fingerlings are being determined for each treatment. |
