Use of freeze-dried microalgae for rearing gilthead seabream, Sparus aurata, larvae - I. Growth, histology and water quality

Four gilthead seabream larval feeding treatments [(A) larvae fed rotifers cultivated with freeze-dried microalgae and daily addition to the larval tank of freeze-dried microalgae; (B) larvae fed rotifers cultivated with freeze-dried microalgae and daily addition to the larval tank of live microalgae; (C) larvae fed rotifers cultivated with freeze-dried microalgae and without addition of microalgae to the larval tank; and (D) larvae fed rotifers cultivated with live microalgae and daily addition to the larval tank of live microalgae) were tested in order to determine if freeze-dried microalgae (Nannochloropsis oculata) was as good as live microalgae for larval rearing at two stages (for rotifer production and into larval tanks). The results showed that larvae can be reared successfully using only freeze-dried microalgae with a survival of approximate to 100% and without altering water quality. Fifteen-day-old larvae were obtained with normal growth in length (5.56 +/- 0.14 mm) and weight (104.46 +/- 1.86 mu g) and with good development of the digestive tract and other associated organs (liver, pancreas). The presence of microalgae (freeze-dried as well as live) in the rearing tanks significantly influenced growth, survival and histological status. (C) 1998 Elsevier Science B.V. All rights reserved.