DEVELOPMENT OF A LARGE‐SCALE Artemia HATCHING SYSTEM UTILIZING RECIRCULATED WATER¹

Abstract

Wide variations in the production of Artemia nauplii were observed among cysts purchased from different suppliers as well as among batches obtained from the same suppliers. Some cysts hatched well after 18 or 24 hours while others required 48 hours to produce maximum availability of nauplii. Hatching salinity (12–36 ppt) appeared to be of relatively little importance as compared to batch and hatching time variations. A study which compared availability of nauplii at 2 salinities (30 and 15 ppt) and 2 hatching times (24 and 48 hours) indicated that cysts from 5 batches hatched as well or better in the lower salinity water (15 ppt). Finally, the hatching of cysts in solutions of synthetic sea salts or block salt (NaCl) resulted in the availability of similar numbers of nauplii. A detailed description of a large‐scale Artemia hatching system using recirculated water is provided. The system consists basically of 2 950‐liter conical bottom hatching tanks, a nauplii/cyst separation tank, and a biological filter and water reservoir. It was designed to eliminate electrical hazards and to be semi‐automated. The system is relatively simple to operate and results in efficient hatching of cysts. The incorporation of a recirculating water system permits maintenance of optimal water quality throughout the hatching period and results in the conservation of materials and energy.