Tank culture of sunshine bass without using rotifers

Authors: Ludwig, Gerald; LOCHMANN, STEVE - UAPB

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2008
Publication Date: 7/29/2009
Citation: Ludwig, G.M., Lochmann, S. 2009. Tank culture of sunshine bass without using rotifers. North American Journal of Aquaculture. 71:224-228.

Interpretive Summary: Until now, rotifers were thought to be required to culture of sunshine bass, a hybrid of white bass and striped bass, in tanks from larvae to fingerlings. These fish have very tiny mouths when they first feed and require very tiny live food. Cultured fresh or brackish water rotifers appeared to be the only available food small enough for the larvae to consume. Once the larvae ate enough of the rotifers they grow large enough to prey on cultured brine shrimp nauplii. Rotifers are usually only fed for less than of week and their culture requires many costs such as equipment, time, space and qualified personnel. Rotifer culture is also risky because cultures may die unexpectedly. Because of the need for rotifers and the cost of their culture it is prohibitively expensive to culture sunshine bass fingerlings in tanks. Recently a brine shrimp variety that has eggs (microcysts) and nauplii that are about 3/4ths the size of previously used eggs and nauplii has become commercially available. An experiment was performed at HKD-SNARC that compared the survival and growth of sunshine bass larvae fed the customary rotifers and then regular size brine shrimp with larvae fed only microcyst nauplii and also larvae fed only regular size brine shrimp. Survival was significantly higher for larvae fed microcyst brine shrimp nauplii and larvae fed rotifers and brine shrimp nauplii (37.9% and 93.6%, respectively). Larvae fed microcyst Artemia nauplii (7.26 mm SL) and larvae fed rotifers and brine shrimp nauplii (7.13 mm SL) were significantly longer than larvae fed brine shrimp nauplii (6.86 mm SL). This experiment is the first time that sunshine bass have been cultured to 14 dph on brine shrimp nauplii without rotifers at first feeding. Brine shrimp are easily and dependably cultured. The elimination of the need for rotifer culture should substantially reduce the cost of culturing sunshine bass fingerlings in tanks.

Technical Abstract: Previously reported protocols for culture of sunshine bass larvae to fingerling size in tanks involved an initial feeding of rotifers for several days before the larvae were weaned to Artemia nauplii and prepared feed. Maintaining rotifer cultures requires space, time, equipment, supplies, and trained culturists. The rotifer cultures are often unstable, which increases risk of poor sunshine bass fingerling production in tanks. Elimination of the use of rotifers would greatly enhance the feasibility of reliable tank culture of fingerlings and should reduce production cost. This experiment compared of three treatments with three replicates per treatment. In one treatment larvae were initially fed rotifers (Brachionus plicatilis) and then weaned to Artemia nauplii (0.48 mm X 0.19 mm). In a second treatment larvae were fed Artemia nauplii throughout the experiment. In a third treatment larvae were fed microcyst Artemia nauplii (0.43 mm X 0.18 mm) for the entire experiment. Sunshine bass larvae, 4 dph, were stocked into 100-L tanks at 75 larvae/L. Larvae were fed according to the three treatments until 14 dph. Only 4.3% of the larvae fed Artemia nauplii survived. Survival was significantly higher for larvae fed microcyst Artemia nauplii and larvae fed rotifers and Artemia nauplii (37.9% and 93.6%, respectively). Larvae fed microcyst Artemia nauplii (7.26 mm SL) and larvae fed rotifers and Artemia nauplii (7.13 mm SL) were significantly longer than larvae fed Artemia nauplii (6.86 mm SL). This experiment is the first time that sunshine bass have been cultured to 14 dph on Artemia nauplii without rotifers at first feeding.