Successful Replacement of Artemia salina nauplii with Marine Rotifers (Brachionus plicatilis) in the Diet of Preadult Zebrafish (Danio rerio)

Previously established rearing protocols for zebrafish begin feeding with marine rotifers (Brachionus plicatilis), followed by Artemia nauplii until the fish reach subadult stage, the developmental time point at which they can be most easily transitioned onto a processed diet. However, the inclusion of Artemia is less than ideal, given its fluctuating availability and high costs. We tested whether or not we could replace Artemia with rotifers during our normal rearing sequence and still meet published performance standards for (i) weaning fish onto a processed diet by 25 days postfertilization (dpf) and (ii) successful breeding by 60dpf. Here, we present the results of trials where wild-type and casper zebrafish were fed exclusively with rotifers (R) or rotifers followed by Artemia (RA) for the first 25dpf after which point all fish were transitioned to a processed diet (Gemma Micro 300). We measured growth and survival at days 25 and 60, and tested for reproductive capability at 60dpf. While growth performance was significantly better in the RA groups, we were still able to meet goals for both weaning and generation time in the R groups without compromising survival or sex ratios.