THE EFFECT OF MOTILITY SPACE AND USING THE SNAIL Achatina sp. AS FEED FOR GROWING THE MUD CRAB Scylla serrata IN FLOATING CAGE AT THE TRADITIONAL CULTURE POND IN MANGROVE AREA, BOLAANG MONGONDOW NORTH SULAWESI

• Main Author: Sulhandi
• Format: Theses
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/35988
• Institution: Institut Teknologi Bandung

The mud crab Scylla serrata is very popular sea food not only in domestic market but also in overseas market. Since the increasing demand for mud crabs, it is a challenge to increase its production sustainably. If the crab production base on the direct catch from nature it would be problems cause scarcity. One of the mud crab cultures can be carried out is by a floating cage system. The fragmented floating cages were designed for an individual crab in order to avoid cannibalism impact. The purpose of this study was to study the best motility space for growing mud crab by using the floating cages, placed in traditional culture ponds; and to know the best snail feed percentage for mud crab (S. serrata). The sizes of motility space as treatments were designed as follows 4500 cm3, 18.000 cm3 and 40.500 cm3, respectively and the percentage treatments of snail feed (Achatina sp) were 3 %, 5 %, and 7 % of the crab weight. Initial body weights of used mud crab had range between 55.1 g – 58.1 g, with length and width of carapaces were 4.8 – 5.0 cm and 6.8 – 7.0 cm, for 70 days culture period. Parameters observed were body weight increasing, carapace length and carapace width, correlation of body weight, carapace length and carapace width, daily growth rate, survival number, biomass, frequency of molting, and FCR. Physicochemicals of water observed were salinity, temperature, water depth transparency and pH). The results of this study showed that the treatments of motility spaces, and snail feed percentages were significantly different (p < 0,05). The floating cage with size 40.500 cm3 and 5% feed weight had the highest production in terms of body weight increasing, length and width increasing of carapaces, biomass, daily growth rate, survival, and frequency of molting. The lowest value of FCR was found at 2.3.