Mr.
Title:
Mr.
Keywords:
Abstract:
The study on the growth performance of mud crab (Scylla serrata) juveniles in floating cages was conducted at the Zamboanga State College of Marine Sciences and Technology (ZSCMST) marine water fishpond from March 09 to June 06, 2001. It was aimed at determining whether a significant difference on the specific growth rate (SGR) of mud crab (Scylla serrata) fed with kuhol between sexes (male and female), and in three different feeding rates can be observed, while an optimum feeding level was also being considered. Chopped kuhol was given at 5%, 10% and 15% biomass daily basis. Crabs weight and carapace lenght were regularly monitored every 15 days interval. The study initially employed six treatment combinations and was later reduced to four treatments due to mortality in other cages. Four treatment combinations were used; Treatment 1 (male with 5% biomass feed), Treatment II (female with 5% biomass feed), Treatment III (male with 10% biomass feed), Treatment IV (female with 15% biomass feed). A Completely Randomized Design (CRD) with two replication was used. Study results reveal no significant difference at 5% level in the Specific Growth Rate (SGR) and carapace width increase of the crabs in the different treatment combination. Molting frequency was high in males at 10% biomass than that at 5% biomass feed. Females have low molting frequency and were not affected by the different feeding rates. There was no great variation in the water parameter which ranges from 28-31 C (Temperature), 32-34 ppt (salinity), 7.9-8.7 (pH) and 4.8-5.6 (dissolved oxygen) on the average.??
Objectives:
It was aimed at determining whether a significant difference on the specific growth rate (SGR) of mud crab (Scylla serrata) fed with kuhol between sexes (male and female), and in three different feeding rates can be observed, while an optimum feeding level was also being considered.
Methods:
Completely Randomized Design (CRD)
Findings and Results:
A negative specific growth rate value was obtained on the first 15 days of culture. This is evident since there is also a decrease in the weight of the crabs from the initial stock to the first sampling period . These decrease was attributed to the slow intake of food by the crab as evidence of remnant foods noticed during during feeding. This slow intake is believed to be the result of the new feed (kuhol) being introduced and the adjustment of crab for both the both the food and environment (floating cage) alike and it is possibly contributed by stress factor. Some of the stocks were taken from Curuan dealer where inappropriate sorting and picking was noticed. However, specific growth rate abruptly increased to some extent in some treatment. Specifically Treatment IV on the 15th day and 30th days of culture, and Treatment III on the 45th , 60th and 75th days of sampling. Due to crabs staggered growth basis, the increase in size took over only after molting. After molting an abrupt increase in size and weight follows. It was futher noted that crabs in the advent of molting slows down its feeding and regain after molting. However, there is no significant difference among treatment means indicating that feeding rates did not significantly affect increase in the carapace width.
Conclusion:
Average growth in terms of specific growth rate (SGR) monitored at 15 days interval showed that Treatment IV recorded the highest on the first and second sampling with 1.565 and .980 SGR but was surpassed by Treament III on the 3 rd, 4 th and 5 th sampling with 1.145,.920 and 0.900 percent growth per day respectively. Treatments I and II also followed just behind Treatment III in the 5th sampling with both .550 percent growth per day. Treatment III underwent 3 molts for the two replicates while all the other treatments with two molts only during the 75 days culture period. Based on the results of the study, the following are recommended: 1. Pure kuhol meat does not give substantial growth and therefore should be used as suopplementary food in combination with other feeds. 2. A combination of feed made up of mollusk, fish, and carbohydrate should be tested for food of crab. This has been tested in sugpo where an imminent growth was observed. 3. A 10% body weight feed will suffice for male mud crab however futher test is necessary to validate results. 4. Futher studies should be conducted to develop appropriate feeds and feeding regimes.
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