Now showing items 1-2 of 2

    • Article

      Effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, growth and survival of early-stage grouper Epinephelus coioides larvae 

      JD Toledo, NB Caberoy, GF Quinitio, CH Choresca & H Nakagawa - Fisheries Science, 2002 - Springer Verlag
      A series of experiments were conducted to examine the effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage Epinephelus coioides larvae. Newly hatched larvae were transferred to 40-L aquaria at a density of 1500 individuals/aquarium. Larvae were exposed to different levels of aeration (0 mL/min per L, 0.62 mL/min per L, 1.25 mL/min per L, 2.50 mL/min per L, or 3.75 mL/min per L); salinity (8 ppt, 16 ppt, 24 ppt, 32 ppt, or 40 ppt); and light intensity (0 lx, 120 lx, 230 lx, 500 lx, or 700 lx) for 4–6 days. Twenty larvae were sampled daily at 11:00 hours to measure for total length (TL), oil globule volume, and feeding incidence. Survival rates were determined by counting the total number of larvae remaining in each aquarium at the end of the experiment. Significantly higher survival rates (P < 0.05) were observed at aeration levels of 0.62 mL/min per L and 1.25 mL/min per L, at salinity levels of 16 ppt and 24 ppt, and at light intensities of 500 lx and 700 lx. The influence of aeration level, salinity and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage grouper larvae are discussed.
    • Book chapter

      Environmental factors affecting embryonic development, hatching and survival of early stage larvae of the grouper (Epinephelus coioides) 

      JD Toledo, NB Caberoy & GF Quinitio - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      These series of experiments were conducted to determine the effects of density (200, 400, 800 and 1600 eggs/litre), salinity (8, 16, 24, 32 and 40 ppt), aeration (0, 0.62, 1.25, 2.50 and 3.75 ml/min/litre) and light intensity (0, 120, 230, 500 and 700 lx) on the survival of fertilized eggs and early stage larvae of Epinephelus coioides. Under statice incubation conditions, the highest egg viability, hatching rate and percentage of normal larvae were obtained at a stocking density of 400 eggs/litre with moderate aeration (100 ml/min) and salinity of 32-42 ppt. Gentle aeration at 0.62 to 1.25 ml/min/litre, rearing water of 16 to 24 ppt and a light intensity of 500 to 700 lx maximized the survival of early stage E. coioides larvae in the hatchery.