Effect of water treatment and aeration on the percentage hatch of demersal, adhesive eggs of the bullseye puffer ( Sphoeroides annulatus)

The bullseye puffer ( Sphoeroides annulatus) is a species with potential for aquaculture. However, preliminary studies on the biology and reproduction of the species in captivity have failed to produce consistent success at hatching. In this study, the effect of aeration and water treatment (filtration and ultraviolet (UV) sterilisation) on percentage hatch was assessed in a replicated experiment repeated on two occasions. Four treatments were used, filtered water (5 μm) treated with UV, in an aerated system (AT) and a static system (ST); water that had been coarse-filtered (20 μm) and not exposed to UV kept in aerated system (ANT) and a static system (SNT). The percentage hatch was ranked 87.5±5.0>80.6±9.4>77.2±12.8>62.8±10.4 (mean of all replicates from both experiments±S.D.) for the respective treatments AT>ST>ANT>SNT. However, percentage hatch for AT was only significantly ( P