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Effect of diet and rearing conditions on growth and survival throughout developmental stages of larvae and juveniles of dusky grouper Epinephelus marginatus (Lowe 1834)

Author:
Cabaleiro, Santiago, Barreiro, Lucía, Caamaño, Rubén
Source:
Aquaculture international 2018 v.26 no.4 pp. 1109-1118
ISSN:
0967-6120
Subject:
Epinephelus marginatus, Rotifera, animal growth, cannibalism, death, diet, energy efficiency, fluorescent lamps, grouper, juveniles, larvae, metamorphosis, rearing, survival rate, tanks, trapping
Abstract:
Two rearing conditions, tank light-dimensions and diet, were tested in dusky grouper—larvae and juveniles—in order to improve larval rearing techniques for this species. Larvae reared in high-volume and fluorescent tubes showed the highest survival rate at 18 dph (17.67%, 16%). This might be due to a higher depth and less trapping area during surface death in high-volume tanks than in low volume. Besides, a 500-lx evenly distributed light with fluorescent tubes might improve survival rate at early stages rather than illumination with energy-efficient light bulbs (4.68%, 9.64%). Light bulbs created shaded areas with less illumination inducing low larval activity. First feeding was performed with minimum rotifer lorica width of 102 ± 10.2 μm. No mixed diet was supplied. Throughout metamorphosis, stress shock syndrome appeared to be the main cause of mortality. Diet A showed best growth and survival (4.1–7.36%) during this period probably due to its high HUFA content (9.5%). Contrary to what was observed during first stages, groupers showed best performance with lower illumination. Cannibalism was observed during this period in all culture conditions.
Agid:
6000692