Embryonic development of adriatic sturgeon, Acipenser naccarii (Bonaparte 1836), in farming conditions: a guide

The sequence and timing of the embryonic development of Adriatic sturgeon (Acipenser naccarii) are described at a constant temperature (17 +/- 1 degrees C), from fertilisation to hatch in a hatchery. Fertilised eggs, obtained from one female and two males, were held in a flow-through system. On the first day, embryos were sampled every 20min during the first 12h, and every 40min in the following 12h. Embryos were sampled hourly on the second day. On the third and fourth days, embryos were sampled every 2h, and every 3h on the fifth and sixth days. The first cleavage furrow appeared at 1h 40min postfertilisation. Blastulation concluded at 12 HPF (hours postfertilisation), when the dorsal blastopore lip formed. The completion of gastrulation was at 18 HPF, closing of the neural tube at 23 HPF and formation of the s-shape heart at 31 HPF. The mass hatch occurred at 120 HPF. A.naccarii is a relatively common sturgeon species in aquaculture and possesses similar developmental patterns to those of other sturgeons; hence, we can use this species as a model for further studies about sturgeon species which are more difficult to breed artificially. Information about the embryonic development of the Adriatic sturgeon could assist restocking programmes.