Now showing items 15-22 of 22

    • Conference paper

      Kappaphycus and Gracilariopsis meal as binders for diets of tiger shrimp 

      V Peñaflorida & N Golez - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Two locally grown seaweeds, Kappaphycus alvarezii and Gracilaria heteroclada, were tested as binders in diets for shrimp juveniles to minimize the use of wheat flour, a common binder. The seaweeds were washed, dried, ground, and made into paste. Seaweed meals were added to an isonitrogenous diet containing 5% flour at 5, 10 and 15%. The control diet contained 15% flour (no seaweed meal). The diets were fed to juvenile Penaeus monodon for 56 days to assess the acceptability of the seaweed meals in terms of shrimp growth, survival and feed conversion ratio (FCR). Seven dietary treatments, each with three replicates, were arranged in a completely randomized design. Treatment means were compared by analysis of variance and Duncan's multiple range test.Growth of shrimp fed diets with 5% and 10% G. heteroclada, and 10% K. alvarezii did not differ significantly but was higher than the rest of the treatments. Only those fed 10% G. heteroclada had growth similar to those fed the control diet. Diets with 5% and 10% K. alvareziii and 10% G. heteroclada had the best FCR. Shrimp survival decreased as the level of G. heteroclada increased. Survival was not affected by the level of K. alvarezii in the diet.Water stability of the diets was assessed in 4 h. High water stability was observed in the diet with 10% G. heteroclada (91%), 5% G. heteroclada (90%) and the control (90%). The rest of the diets were 87-89% stable. Thus, 10% G. heteroclada or 10% K. alvarezii could be used to supplement 5% flour as binders in shrimp diets with no adverse effect on growth and survival.
    • Conference paper

      L-ascorbyl-2-phosphate Mg as vitamin C source for juvenile Penaeus monodon 

      M Catacutan & C Lavilla-Pitogo - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Phosphated ascorbic acid (magnesium L-ascorbyl-2-phosphate or MAP) is a stable form of vitamin C. The suitability and growth requirement level of this derivative in practical diet was determined for juvenile Penaeus monodon. The stability and shelf-life of this derivative was compared with that of crystalline ascorbic acid in prepared shrimp diets. Leaching test was conducted at time intervals of 0 to 6 hours while storage test was conducted for 2 weeks to 3 months.In Experiment I, shrimps (183-254 mg) were given MAP at 0 to 1,500 mg/kg diet for 92 days. Shrimps given the diet without MAP supplement had the lowest growth, survival and feed conversion efficiency, but these were not significantly different from those of shrimps fed diets containing different MAP levels. The shrimps were infected with monodon baculovirus at the start of the experiment. At termination, the histological structure of the hepatopancreas showed improvement in those fed diets containing MAP at 100 mg/kg diet or higher.In Experiment II, shrimps (126-135 mg) were fed with diets containing MAP at 0-8,000 mg/kg diet. Seaweed was removed from the diet composition. After 81 days, shrimps given diet without MAP had significantly lower survival rate and feed conversion efficiency than the shrimps fed diets with MAP. Growth was lowest in shrimps without MAP but was not significantly different from that of shrimps given MAP. After feeding for 81 days on diets with different MAP levels, the shrimps were wounded and further maintained with their respective dietary treatments to observe the effects of MAP in wound healing. Complete healing of wounds were observed after two weeks among shrimps given with MAP at 100 and 200 mg/kg diet. In both experiments, shrimps without dietary MAP were weak and showed symptoms of vitamin C deficiency. Higher levels of MAP did not result in very high mortalities in shrimps. This study showed that MAP was utilized by P. monodon as a vitamin C source and the adequate level would be about 100 to 200 mg/kg of diet or 50 to 100 mg as ascorbic acid per kg diet.
    • Conference paper

      Nutritional requirements of commercially important shrimps in the tropics 

      M Boonyaratpalin - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The culture of tropical shrimps has gained greater economic importance particularly among Southeast Asian countries. As shrimp fanning moves from low-input, low-technology operation to the intensive and even highly intensive scales of operation, farmers are increasingly seeking ways to achieve more efficient means of production. Feed takes up the major portion of the cost of production. It also has a significant effect on the health of cultured species. Therefore, nutritional adequacy and cost-effectiveness of feeds are critical to the growth of the aquaculture industry. This paper discusses the nutritional requirements for growth as well as for health of some commercially important shrimp species in the tropics with emphasis on P. monodon.
    • Conference paper

      A preliminary study on the effect of hypoxia on carotenoid metabolism in black tiger shrimp Penaeus monodon Fabricius 

      FI Heralde, M Leaño, A Reyes & R Coloso - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The pigmentation of black tiger shrimp Penaeus monodon is due to astaxanthin, astaxanthin monoester, and astaxanthin diester. These carotenoids are biosynthesized from beta-carotene or zeaxanthin. Biosynthesis is postulated to be mediated by the enzymes C3 and C4 monooxygenase and caroten-4-ol dehydrogenase. Blue-shrimp syndrome, characterized by low total astaxanthin levels in shrimp epidermis, is associated with nutritional deficiency for carotenoids but other factors such as high organic matter, hypoxia, high density, and high pH may also be involved. In this study, the effect of hypoxia on carotenoid metabolism in P. monodon was investigated with respect to retention and transformation of carotenoids and the activity of the enzymes C3 and C4 monooxygenase and caroten-4-ol dehydrogenase.Two tanks were prepared each containing 25 pieces of shrimp fed a control diet (not containing any carotenoid) for two weeks. Shrimps in one tank (Treatment 1) were given beta-carotene supplemented diet (3.8 ppm) in the next two weeks while those in the other (treatment 2) were fed the control diet. Two days after introduction of the test diets, both treatments were subjected to hypoxia challenge (dissolved oxygen, 2.5-2.7 mg/L) and the carotenoid content and profile of feces monitored for succeeding days. Assay of enzyme activity was performed five days after hypoxia challenge. Results showed a ten-fold increase in fecal total carotenoid content of shrimps in treatment 2 (122.2 ppm) compared with that in treatment 1 (12.4 ppm) on hypoxia challenge and restores to basal level (3.9-4.1 ppm) after three days. The carotenoids found in the feces of shrimps in treatment 2 were astaxanthin, astaxanthin monoester, astaxanthin diesters, and an unidentified carotenoid which was also found in the muscle of stressed shrimp. Using beta-carotene as substrate, conversion to astaxanthin was not observed in the hepatopancreas homogenates of shrimps in both treatments. Instead, a slow conversion of astaxanthin to betacarotene (i.e., a reverse reaction) was noted in treatment 2 exhibiting twice the activity in treatment 1. Radiolabelling studies using 14C-labelled astaxanthin as substrate confirmed the existence of this enzyme-mediated reductive pathway from astaxanthin which occurs at a very slow rate. This study demonstrated the carotenoid-depleting effect of hypoxia on shrimp, both through enhanced fecal release and moderately elevated reductive pathway from astaxanthin. This effect suggests a possible mechanism by which blue-shrimp syndrome may develop.
    • Conference paper

      Reproductive performance of captive Penaeus monodon fed various sources of carotenoids 

      ET Quinitio, FD Parado-Estepa, OM Millamena & H Biona - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Three groups of pond-reared Penaeus monodon broodstock were fed formulated diet in combination with carotenoid-containing natural food: mussel + shrimp broodstock pellet (MBP), crab + BP (CBP), and Artemia + BP (ABP). After four months, maturation and spawning rates did not differ significantly among treatments. After eyestalk ablation, MBP-fed shrimps Initially spawned 20 days; 34 days for CBP-fed; 50 days for ABP-fed shrimps. The number of eggs per g body weight of spawner (1616-2359 eggs /g BW) did not differ significantly among all groups. Only nauplii from MBP-fed broodstock reached postlarval stage. Rematuration was observed only in MBP- and CBP fed shrimps. Sperm count was highest in MBP- and lowest in ABP-fed shrimps at the final phase of the test.
    • Conference paper

      Screening of inexpensive and indigeneous ingredients for use in practical feed for juvile sea bass (Lates calcarifer Bloch) 

      RM Coloso, JR Hipolito & D Murillo - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An eight-week feeding experiment with juvenile sea bass (about 15 g) was conducted in 500-1 fiberglass tanks to screen the most cost-effective practical diet for use in ponds and floating cages. Eleven formulations and one control feed were tested. Protein sources used were locally available ingredients such as fish meal, shrimp head meal, scrap squid meal, cow's blood meal, poultry feather meal, leaf meals, soybean meal, and mung bean meal. The diets contained a combination of animal and vegetable protein sources such that the essential amino acid composition was close to the requirement or tissue levels. Crude protein and fat levels were about 42% and 8.3%, respectively. Fish were fed ad libitum twice a day at 0800 and 1600 h. Best weight gain (189%) and feed conversion ratio (FCR, 1.7) were observed in fish given a combination of fish meal, shrimp head meal, scrap squid meal, soybean bean meal, and kangkong leaf meal as protein sources. This was followed by those given a combination of fish meal, shrimp head meal, scrap squid meal, soybean meal, and ipil-ipil leaf meal (139% weight gain, FCR of 2.2). Worst growth (22%) and FCR were observed in fish given a combination of fish meal, cow's blood meal, scrap squid meal, soybean meal, and mulberry leaf meal. Control fish given a combination of fish meal, shrimp meal, and soybean meal showed weight gain of 195% and FCR of 1.8. Survival was high (83-100%) in all treatments. The two diets which gave the best growth rates, survival, and FCR in the screening phase can be tried in ponds and floating net cages.
    • Conference paper

      Use of the golden apple snail, cassava, and maize as feeds for the tiger shrimp Penaeus monodon in ponds 

      I Bombeo-Tuburan, S Fukumoto & E Rodriguez - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Penaeus monodon stocked in ponds at 8,000/ha were fed four types of farm-made feeds starting on day 16 of a 4-month culture period. The feeds were golden apple snail alone or in combination with cooked cassava or maize, or maize alone. Mixed feeds resulted in significantly higher production and better size-frequency distribution of shrimp. Survival (88-99%) was not significantly different among the treatments. Maize alone and snails alone were inadequate. Presumably, the high amount of carbohydrate in cassava (92%) or maize (87%) provided the needed energy, and the high protein content of golden snail (54%) was available for growth. The fatty acid profile of the golden snail shows that it is a good source of 18:2n-6, 18:3n-3, and 20:5n-3 which are essential fatty acids for P. monodon. Golden snails, with an essential amino acid index (EAAI) of 0.91, are a suitable alternative source of protein for tiger shrimp. Feeding shrimps with golden snails and cassava yielded the highest net income (P 49,332/ha-crop) and return on investment (ROI = 213%) better than feeding with maize alone (net income = P 23,626/ha-crop; ROI = 125%). If shrimp farmers tap golden snails as direct feed or as feed ingredient, the problem of snail infestation in rice fields may be reduced.
    • Conference paper

      Weaning of the Asian catfish, Clarias macrocephalus Gunther, larvae to formulated dry diet 

      AC Fermin & MEC Bolivar - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Two feeding trials lasting 10 days each were conducted to determine the weaning time in the Asian catfish, Clarias macrocephalus, larvae to dry diet feeding. Three-day-old catfish larvae were fed newly-hatched Artemia nauplii for 2,4, and 6 days after which ad libitum feeding with a commercial feed (trial 1) or a formulated diet (trial 2) was started. Fish fed exclusively dry diet (0-day Artemia feeding) or those fed only Artemia for 10 days served as the controls. In trial 1, fish fed Artemia at different durations had significantly higher growth and survival than those reared exclusively on dry diet. In trial 2, percent survival was not significantly different among fish with or without Artemia pre-feeding. However, fish had significantly higher final body weight and SGR when reared initially on Artemia prior to dry diet than those fed exclusively dry diet. Based on the results, catfish larvae can be successfully weaned to dry diet after feeding Artemia for a maximum period of four days (ave. BW=12.25 mg).