Growth and Survival of Milkfish (Chanos chanos) Fry in Different Cage Shapes

The study on the growth and survival of milkfish (Chanos chanos) fry in different cage shapes was conducted at the College of Fisheries Laboratory and Research Station, Sony Bawing, General Santos City for a period of 45 days from January 25 to March 12, Three types of cages classified as rectangular (1.2m x 0.8m x 1.5m), square (1m x 1m x 1.5m) and circular (diameter=1.13m; height=1.5m) were used as enclosure for the experimental animals and were installed in the pond. Thirty five (35) milkfish fry with an initial weight of 0.142g were stocked per cage. A Complete Randomized Design (CRD) was used in the study with three (3) treatments replicated three (3) times and labeled accordingly. The fish were fed commercial diets with approximate crude protein (CP) of 33% and fed at feeding rate of 10 % of their body weight in the first 30 days and adjusted to 8 % for the next 15 days for all treatments. Statistical analysis was done using the IBM SPSS Statistics (Version 20). The significance between treatments means was determined using Duncan Test. The highest mean final body weight was obtained by fish in Treatment III with 5.95g, followed by Treatment I with 5.45g and ‘Treatment II with 4.94g. The highest mean weight gain was obtained by fish in Treatment III with 5.81, followed by Treatment I with 5.31g and the lowest in Treatment II with 4.80g. Fish in Treatment III obtained the highest mean daily weight gain of 0.13g/day, followed by Treatment I with 0.12g/day and the lowest was gained by Treatment II with 0.11 g/day. Statistical analysis showed significant difference among treatment means (P<0.05). When growth parameters were subjected to Duncan's Multiple Range Test (DMRT), mean final weight gain, mean weight gain and mean daily weight gain showed that all treatments were significantly different (P<0.05) with each other. Better feed conversion ratio (FCR) was obtained by Treatment IIl with 0.99 followed by Treatment I with 1.01 and Treatment II with 1.07. Statistical analysis showed no significant difference among treatment means (P>0.05). Temperature readings ranged at 28- 33.2 °C. salinity at 24-32 ppt, pH at 7.1 — 7.7, dissolved oxygen at 2.8 — 6.7 ppm and ammonia at 0.0 ppm. These ranges are found to be within the tolerable range of milkfish. Under the condition of the study, Treatment IIl had the best result in terms of growth and FCR.