Protocol development for the improved hatchery propagation of Tiger grouper Epinephelus fuscoguttatus (Forsskål, 1775) in Palawan, Philippines

Abstract

The expanding grouper cage farming in Palawan, Philippines requires stable seed supplies from hatcheries to sustain the demands of fish cage operators. To improve the current hatchery practices for Tiger grouper Epinephelus fuscoguttatus (Forsskål, 1775), four experiments were undertaken. The first experiment (E1), involving three different temperatures ranges (T1: 24-26°C; T2: 27-29°C; and T3: 30-32°C) revealed significantly higher hatching rates at 27-32°C. The second experiment (E2) found that survival rates after 38 days from hatching were inversely proportional with density (T1: 3; T2: 5; and T3: 10 larvae L-1). The third experiment (E3) found that the growth and survival of fry raised at three different stocking densities for three weeks (from 21 to 42 days after hatching) were not significantly different. The fourth experiment (E4) compared the growth and survival of fingerlings (from 70–91 days after hatching) fed with two brands of commercial feeds. After three weeks, both treatments had comparable total lengths. These desirable results are attributed to the weekly thinning or reduction in the density of juveniles in E3 and E4 and the use of small rearing containers.