Polyculture of Orange-Spotted Grouper (Epinephelus coioides) Fingerlings with Red Seaweed (Gracilaria Spp.) in Brackishwater Pond

A study om the polyculture of orange spotted grouper (Epinephelus coioides) fingerlings with red seaweed (Gracilaria spp.) in brackishwater pond was conducted at the College of Fisheries Laboratory and Research Station, Brgy. Bawing, Gencral Santos City for a period of 60 days from March 1 to April 29, 2019. Ten (10) orange-spotted grouper fingerlings with mean initial weight of 2 g were stocked in nine (9) units of (1m x 1m x 1.5m) net cages. Red seaweed, Gracilaria spp. with 30-60 grams per individual cutting was planted early in the morning using plastic straw “tie-tie" and tied in the nylon within the bamboo frame inside the cage. The seaweed varied in terms of biomass for Treatment I, II and III with 0, 250 and 500 p/m^3, respectively. A Complete Randomized Design (CRD) was used in the study with three (3) treatments and replicated three (3) times and labeled accordingly. Statistical analysis was done using the IBM SPSS Statistics (Version 20). After the 60-day culture, orange spotted grouper in Treatment III obtained the highest mean body with 10.1 1g, followed by Treatment II with 9.49g and Treatment I with 8.81g. The highest mean weight gain was also highest in Treatment III with 8.112, followed by Treatment II with 7.49g and the lowest in Treatment I with 6.81 g. In terms of mean daily growth. Treatment III obtained the highest mean daily growth of 0.14g/day, followed by Treatment II with 0.12p/day and the lowest in Treatment I with 0.11 g/day. Best feed conversion ratio (FCR) was in Treatment III (3.97) followed by Treatment II (3.63) and Treatment I (3.43). Highest mean survival rate was obtained in Treatment III (97%), followed by Treatment II and Treatment III with both 90%. Analysis of Variance (ANOVA) showed that there was no significant difference in mean body weight, mean weight gain, mean daily weight gain, mean feed conversion ratio and mean survival. Water quality parameter readings of temperature, pH, dissolved oxygen, and ammonia ranged from 29.7- 33.2 °C, 7.1 - 7.7, 2.8 — 6.7 ppm and 0 ppm, respectively. These ranges are found to be within the tolerable range for orange spotted grouper. Under the condition of the study, Treatment III (10 fish and 500 g/m3 red seaweed) had the best result in terms of growth, survival and FCR but were not significantly different from other treatments.