UPV Theses and Dissertations
Permanent URI for this communityhttps://hdl.handle.net/20.500.14583/10
Browse
2 results
Search Results
Item Evaluation of commercial shrimp larval diet as replacement of live foods in mudcrab larval rearingBurlas, Michael Rey J. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2014-04)ABSTRACT The use of live food such as rotifer and Artemia entails high cost of production in the hatchery. Hence, the general objective of the study was to reduce the use of natural food in the larval rearing of mud crab. The first study was conducted to screen four types of commercial shrimp formulated larval diet (Lansy, P. japonicus, P. monodon and BP Nippai) in mudcrab Scylla serrata larval rearing. Formulated diets were fed to each stage from zoea 1 to megalopa at an equivalent of 100% dry weight of the live food. Growth index and survival were determined at the end of the experiment. Results showed that of zoea 1 fed any of the formulated diet did not molt to zoea 2. When formulated diets were fed to zoea 2, 3 and 4, there was a decreasing trend in the growth index and survival as the larvae developed. Zoea 5 fed any of the formulated diet failed to molt to megalopa stage. Among the four formulated diets, BP fed larvae had better growth and survival. BP was then used in the second study to determine the amount of formulated diet (FD) that could replace natural food (NF) such as rotifer and Artemia. Results showed that larvae fed 25% FD + 75% NF and 50% FD + 50% NF had better survival and growth than those larvae fed 100% FD + 0% NF, 75% FD + 25% NF and 0% FD + 100% NF. This study indicates that shrimp larval diet in combination with formulated diet can be used to improve the growth and survival of S. serrata larvae.Item The effect of common table salt added in different levels of water salinity as culture medium on growth and survival of prawn larvae Peneus monodon FabriciusAbeto, Mario N. (College of Fisheries, University of the Philippines in the Visayas, 1989-09)A study was conducted on the effect of common table salt added in waters of different salinity levels used to determine the survival rate, developmental stage, and carapace length of Penaeus monodon larvae from zoea one to post larva one. The following treatments which were adjusted to 33 ppt by adding varying amount of common table salt were: treatment I (8 ppt + 29 g/l) , treatment II (13 ppt + 23 g/l) , treatment III (18 ppt + 17 g/1), treatment IV (23 ppt + 11 g/1), and treatment V (28 ppt + 5/g) . Natural seawater with salinity of 33 ppt was used as control. Certain key ions like Na+, CL-, Ca2+, and Mg2+ were analyzed in each treatment. A sharp drop of. population in all treatments was recorded in the first 5 days of the zoeal stage. Treatment V gave the highest survival rate (25%) , but not significantly higher than treatment IV (20.5%) and control (18%); however, significantly higher than treatment III (10.5%) and treatment II (6.5%) at P<0.05. None of the larvae survived in treatment I after 5 days. Larvae exposed to treatment V had completed post larva one in 11 days (growth index 7). This was not significantly different, however, from those obtained from the control (growth index 6.6) and treatment IV (growth index 6.3). The lowest growth index value which was significantly lower than treatment V was obtained from treatment II and treatment III (growth index 6.0). During the first sampling, carapace length in treatment I reached 0.47 mm, succeeded by the following treatments: III (0.43 mm) , II (0.42 mm) , and V (0.40 mm). Treatment IV and control gave similar results (0.30 mm). After 2 days, rate of increase of CL had shifted from lower to high ionic concentrations culture media. At the end of the study the following carapace lengths were obtained: 1.2 mm for treatment V, 1.15 mm for control, and 1.08 mm for treatment IV. Values obtained from treatment II (0.94 mm) and treatment III (0.98 mm) were significantly lower than treatment V (1.15 mm) . Rearing waters with higher concentrations of K+ and Mg2+ (control, treatments I, and II)showed better growth rate and percent survival than those media with relatively lower concentrations (treatments I, II, and III) . The addition of common table salt to low saline waters, however, did not compensate for the loss of physiologically important ions needed for growth and survival of prawn larvae.