Now showing items 1-20 of 46

    • Article

      Commercial evaluation of monosex pond culture of the mud crab Scylla species at three stocking densities in the Philippines. 

      AT Triño, OM Millamena & C Keenan - Aquaculture, 1999 - Elsevier
      The effects of three levels of stocking density (0.5, 1.5 or 3.0 m−2) and monosex culture (male or female) on the growth, apparent feed conversion ratio (FCR), survival, and production of mixed species of mud crabs, Scylla serrata and S. tranquebarica, were investigated. The juvenile crabs were stocked in 150 m2 earthen ponds with Gracilariopsis bailinae as shelter and fed a mixed diet of 75% fresh mussel flesh and 25% fish bycatch. There was no interaction between stocking density levels and monosex culture (P<0.05) so that data were pooled for each sex or stocking density treatment. Highest survival and the most efficient FCR were obtained from stocking density of 0.5 m−2 (P<0.05). Crab growth rates in different stocking densities were not significantly different (P>0.05). Male crabs attained significantly higher (P<0.05) final weight and specific growth rate (SGR) than female crabs. However, final crab length, width, FCR, survival, and production were not significantly different between male and female crabs (P>0.05). Highest return on investment (ROI) and lowest production cost were obtained from 0.5 m−2. Partial budgeting analysis showed that no net benefit accrued from stocking beyond 1.5 m−2. Both male or female monosex cultures gave high net revenue and ROI of more than 100%. Results suggest that the culture of male or female mud crabs at 0.5–1.5 m−2 is economically viable but male monosex culture is more profitable.
    • Book chapter

      Development of formulated feeds for grow-out culture of grouper (Epinephelus coioides) - tank and field studies 

      OM Millamena & JD Toledo - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      The objectives of this study were to compare the performance of a Southeast Asian Fisheries Development Centre (SEAFDEC) formulated diet with a commercial feed for growout culture of grouper and to transfer technology on grouper diet developed at SEAFDEC to the industry. In the tank study, Epinephelus coioides juveniles were reared in 12 units of 150-litre tanks at 15 fish/tank with 4 replicates per treatment. Fish were fed the diets at a feeding rate of 5-6% of body weight (BW) and trash fish at 10-12% BW per day for 60 days. In the feeding trial, treatments were arranged in a randomized complete block design with size groups as block. 36 fish were stocked per size group. Formulated feeds were given twice a day for 120 days. In the tank study, the commercial feed resulted to significantly lower growth, survival and food conversion ratio (FCR) compared with the SEAFDEC diet and trash fish control. Results of the field trials at growout ponds did not show significant differences in growth performance, survival and FCR of grouper juveniles fed with the diets. Both the SEAFDEC diet and commercial feed conformed to the established protein requirement of juvenile grouper. In tank trials, the poor performance of commercial feed was attributed to the low protein content and deficiencies in essential amino acids as confirmed by analysis of the amino acid composition. Improvement in growth performance of fish given the commercial feed was achieved in field trials by increasing the dietary protein level and improving the amino acid composition to match that of the grouper juveniles.
    • Article

      Diet development and evaluation for juvenile abalone, Haliotis asinina: protein/energy levels 

      MN Bautista-Teruel & OM Millamena - Aquaculture, 1999 - Elsevier
      Juveniles of abalone, Haliotis asinina with mean initial weight and shell length of 0.6±0.03 g and 15±0.07 mm were fed practical diets for 90 days. The practical diets contained graded levels of protein from fish meal, shrimp meal, and soybean meal at 22 (diet 1), 27 (diet 2), and 32% (diet 3) with corresponding estimated metabolizable energy values of 3254, 3150, and 3090 kcal ME/kg diet. The amino acid profile and proximate analyses of muscle meat of the test animal and published nutrient requirements of other species of Haliotids were used as a basis for formulating and developing these practical diets. The diets were fed to abalone at 2–5% body weight once daily (1600 h) for biological evaluation in terms of weight gain (WG), increase in shell length (SL), specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR) and for physical evaluation in terms of shell coloration of the animal. Natural food, Gracilariopsis bailinae (17% CP/2200 kcal ME/kg) (NF) fed ad libitum served as the control. Better growth rates, in terms of WG and SL, FCR and PER were noted in abalone fed the three formulated diets compared with those fed seaweed, G. bailinae. Abalone fed diets 3 (WG: 347%; SGR: 0.81; SL: 140%) and 2 (WG: 307%; SGR: 0.70; SL: 139%) showed significantly better growth rate than those fed diet 1 (WG: 252%; SGR: 0.51; SL: 132%). Natural food-fed abalone had the lowest WG (134%), SGR (0.06) and increase in SL (77%). Survival was generally high at 85–95% for all treatments. FCR (1.5–2.3) and PER (2.19–2.47) for animals fed the three diets were significantly better than for those fed natural food (0.10 PER and 6.98 FCR). Regression analysis showed the optimum protein level for juvenile abalone to be 27% with an energy level of 3150 kcal/kg ME. Abalone juveniles fed the formulated diets produced shells with light bluish green color while those fed seaweed retained the original brown color. Diet 2 which contained 27% protein, 5% lipid and 40% carbohydrates with an energy value of 3150 kcal/kg ME may be used as a basal diet for the rearing of juvenile abalone, H. asinina.
    • Article

      Effect of detention time on aerobic waste stabilization pond performance in Southeast Asia 

      OM Millamena - Bulletin of Environmental Contamination and Toxicology, 1994 - Springer Verlag
      The rising level of pollution in rivers, lakes and other bodies of water has created problems of significant magnitude in Southeast Asia. Apart from the aesthetic desirability of clean rivers are the pressing dangers to health and detrimental effects on aquatic life. Pollution of these sources must be controlled so as not to interfere with the waters' legitimate uses.

      Waste stabilization ponds are well-accepted as an effective and economical means of waste disposal. A "stabilization pond" is an artificially created body of water intended to retain sewage or organic wastes until biological processes have rendered the wastes stable. The stabilization process consists of bacteria and algae interaction. Bacteria oxidize the wastes and produce sludge, carbon dioxide and ammonia. The nutrients produced from bacterial oxidation, along with light energy, supply the requirements for algal photosynthesis. Algae produce oxygen needed to sustain the treatment process. Optimum detention time refers to the average length of time required for waste to become stabilized within a pond.

      Properly designed and operated, a stabilization pond can provide treatment comparable to a more costly waste treatment plant. However, the design criteria for a particular climate may not be applicable to other climates. This study was conducted to establish suitable detention times for aerobic stabilization ponds in Southeast Asia.
    • Conference paper

      The effect of diet on the reproductive performance of pond-reared Penaeus monodon Fabricius broodstock 

      OM Millamena, JH Primavera, RA Pudadera & RV Caballero - In JL Maclean, LB Dizon & LV Hosillos (Eds.), The First Asian Fisheries Forum: Proceedings of the First Asian Fisheries Forum, Manila, Philippines, 26-31 May 1986, 1986 - Asian Fisheries Society
      Three practical diets were tested for their effects on the reproductive performance, survival and larval quality of pond-reared Penaeus monodon. Diets A, B and C were formulated to contain the same basal components but supplemented with different sources of lipids. Lipid sources were cod liver oil (Diet A), soybean lecithin (Diet C) or their 1:1 combination (Diet B). An all-natural diet consisting of squid and marine annelids served as control. Pond-raised P. monodon were stocked in four 12-m3 flow-through maturation tanks with 28 females and 22 males per tank. Broodstock were acclimated to the diets prior to unilateral ablation of females. Reproductive performance in terms of total number of spawnings, eggs and nauplii production, average hatch rate of eggs and larval quality was best for Diet A followed by Diet C. Diet B gave the poorest overall response but was better than the control. In the control most of the mature females resorbed their ovaries and failed to spawn; survival rates of females was also lowest. The results suggest that nutritional quality of broodstock diet affects reproduction and larval survival. Diet A (cod liver oil supplemented) was found to be a suitable diet for successful maturation and spawning of pond-reared P. monodon.
    • Article

      Effect of fatty acid composition of broodstock diet on tissue fatty acid patterns and egg fertilization and hatching in pond-reared Penaeus monodon 

      OM Millamena - Asian Fisheries Science, 1989 - Asian Fisheries Society
      The effect of dietary fatty acid composition on tissue fatty acid patterns and Penaeus monodon was evaluated with the use of 3 practical diets. Diets were formulated to contain the same basal components but with various lipid supplementation: Diet B1, 6% cod liver oil; Diet B2, 3% cod liver oil and 3% soybean lecithin; and Diet B3, 6% soybean lecithin.

      Three flow-through maturation tanks were each stocked with 50 broodstock at a sex ratio of 1.5 female to 1 male, with the females ablated on one eyestalk. Broodstock performance measured as total number and nature of spawnings, egg fertility and average hatching rate of eggs of each dietary treatment was assessed.

      Results showed that the fatty acid composition of broodstock diet affected the tissue fatty acid patterns and hatchability of eggs from pond-reared P. monodon . Females fed a diet high in 20:4n-6, 20:5n-3 and 22:6n-3 polyunsaturated fatty acids and n-3/n-6 fatty acid ratio gave higher percentages of fertilized eggs and higher hatching rates than did other diets.
    • Article

      The effects of diets on reproductive performance of eyestalk ablated and intact mud crab Scylla serrata 

      OM Millamena & E Quinitio - Aquaculture, 2000 - Elsevier
      The reproductive performance of female mud crabs was evaluated as affected by various diets. Dietary treatments were as follows: D1 — natural diet (mussel meat, squid, trash fish); D2 — combination of natural and formulated diets; D3 — formulated diet. Pond-sourced broodstock, with initial body weight of 300–400 g, were tagged in their carapace then stocked in three units of 10 m3 broodstock tanks at eight females per tank. Half of the females were ablated and the other half were intact. Spawnings were monitored and berried females were transferred to individual 500-l tanks for incubation of eggs. Four experimental runs were conducted. Broodstock response in terms of number of spawnings, spawnings with hatching, fecundity, egg fertilization rate, total zoea produced and broodstock survival was enhanced in females fed the mixed diet (D2) compared to those fed the natural diet (D1) or the formulated diet (D3). Larval quality measured as larval stage index followed the same trend. Results further showed that intact females fed diets D1 and D2 gave higher numerical values in reproductive performance and zoea growth index than ablated females while ablated females fed diet D3 performed better than their intact counterparts. This may be attributed to presence of essential nutrients and vitamins A, C, E in the formulated diet. Latent period from gonadal maturation to first spawning was shortened by eyestalk ablation. Use of a combined diet would ensure the production of good quality eggs and large numbers of zoea with the best chance of completing the larval stages and thus, would serve as an appropriate starting point in establishing a viable mud crab aquaculture.
    • Article

      Effects of various diets on the nutritional value of Artemia sp. as food for the prawn Penaeus monodon 

      OM Millamena, RF Bombeo, NA Jumalon & KL Simpson - Marine Biology, 1988 - Springer Verlag
      The nutritional value of Artemia sp. as food for marine fish and crustacean larvae has been linked to the level of its polyunsaturated fatty acid (PUFA) content. Experiments in August 1984 were conducted to determine the effects of various artificial diets and algae on fatty acid composition of PUFA-deficient Artemia sp. (Utah GSL strain) and their resulting value as food for postlarvae of the prawn Penaeus monodon (Fabricius). Nauplii of the brine shrimp were grown on extracts of corn, copra, soybean and rice bran containing precursors (C18) to long-chain PUFA and also on algal species containing different levels of long-chain PUFA (C20). The nauplii were then used as food for P. monodon postlarvae. The results revealed that absence of C20 polyunsaturates from the feeds and their presence in the algae were reflected in the polyunsaturated fatty acid content of the tissues of Artemia sp. When fed with brine shrimp fed on algae, P. monodon displayed better postlarval survival and significantly higher growth; related to the content of polyunsaturated fatty acids in Artemia sp. A practical feeding approach in prawn hatcheries would be to grow Artemia sp. on a cheap diet such as rice bran, and then to enhance its nutritional value with a diet high in PUFA prior to harvesting, in order to improve hatchery production.
    • Book chapter

      The essential nutrients: Carbohydrates 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This section discusses the difference among the various forms of carbohydrate and their significance in fish nutrition; distinguish between utilization of carbohydrates by warmwater and coldwater fishes and know how dietary carbohydrates are made available to fish.
    • Book chapter

      The essential nutrients: Energy 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      After studying this section, the reader should be able to differentiate the forms of energy and their measurement. Understand dietary energy metabolism, the energy balance equation and factors that influence dietary energy requirement of fish; and understand the significance of optimal protein to non-protein energy in fish diets.
    • Book chapter

      The essential nutrients: Lipids and fatty acids 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The objective of this section is to acquaint the reader about common fatty acids, their nomenclature and formulas, and differentiate between saturated and unsaturated fatty acids; to know how environmental factors (temperature, salinity, diet) influence the fatty acid composition of fish; the mechanisms of fatty acid biosynthesis and oxidation, and factors that favor fatty acid biosynthesis and oxidation; the effects of lipid peroxidation and the function of antioxidants; and to understand the importance of fatty acid profiles in fish nutrition, and differences in the essential fatty acid requirements of warmwater and coldwater fishes.
    • Book chapter

      The essential nutrients: Minerals 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This section discusses the macro, micro, and trace minerals; their physiologic functions; and deficiency signs and symptoms. It also gives a summary of the mineral functions and mineral requirements of fishes and shrimp.
    • Book chapter

      The essential nutrients: Proteins and amino acids 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This section aims to teach the reader the ten essential amino acids required by fish and their chemical structures, distinguish between essential and non-essential amino acids; the fate of absorbed amino acids in fish; effects of deficiencies and excesses of dietary amino acids in fish diets; the procedure on how to determine the qualitative and quantitative amino acid requirements of fish; methods of evaluating protein quality; and how to determine protein requirements of some aquaculture species.
    • Book chapter

      The essential nutrients: Vitamins 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This section describes the various lipid-soluble and water-soluble vitamins, their differences, physiological functions, and the symptoms of vitamin deficiencies in fish. It also shows a summary of nutritional deficiency signs and the requirements of various fish species for vitamins.
    • Article

      Evaluation of processed meat solubles as replacement for fish meal in diet for juvenile grouper Epinephelus coioides (Hamilton) 

      OM Millamena & NV Golez - Aquaculture Research, 2001 - Blackwell Publishing
      Feeding experiments were conducted to determine the efficacy of low fish-meal-based diets for juvenile grouper Epinephelus coioides (Hamilton). A diet containing 44% protein was formulated using fish meal as the major protein source. Processed meat solubles, a rendered by-product of slaughterhouses, was tested as a replacement for fish meal at increasing percentages from 0 to 100% in isonitrogenous diets. Eight dietary treatments representing fish-meal replacements were arranged in a completely randomized design with four replicates per treatment. Twenty-five fish were reared in circular fibreglass tanks of capacity 250 L, maintained in a flow-through seawater system and fed at 5–6% of total biomass, provided daily at 08:00 and 16:00 for 60 days. Results indicate that processed meat solubles can replace 40% of fish-meal protein with no adverse effects on weight gain, survival and or feed conversion ratio of E. coioides juveniles. Higher inclusion levels resulted in a significant decline in growth performance and inefficient feed conversion ratios, which may partly result from the lack of essential nutrients such as essential amino acids in meat solubles. This study has shown that the use of processed meat solubles substantially lowers the level of fish meal required in juvenile grouper diet and can be an efficient means of turning byproducts from slaughterhouses into a useful feed resource.
    • Article

      Food value of Brachionus plicatilis fed three selected algal species as live food for milkfish, Chanos chanos Forsskal, fry production 

      CT Villegas, O Millamena & F Escritor - Aquaculture and Fisheries Management, 1990 - Blackwell Publishing
      The effects of three selected algal species, Tetraselmis tetrahele, Isochrysis galbana and marine Chlorella sp. on the population growth of Brachionus plicatilis was evaluated after 3, 5 and 7 days of culture. The rotifers fed on T. tetrahele showed superior growth with mean peak density of 92.5 individuals per ml to those fed on I. galbana (48.2 individuals per ml) and Chlorella sp. (47.2 individuals per ml) in 5 days.

      In another experiment, milkfish. Chanos chanos Forsskal, fry with initial mean body weight and standard length of 6.26 ± 1.07mg and 13.04 ± 1.40mm, respectively, were fed B. plicatilis reared on the three algal species for 30 days. Results showed that growth, measured in terms of gain in weight and length, was significantly different (P > 0.05) among treatments. Fastest growth was obtained in fry fed B. plicatilis cultured on T. tetrahele with mean gains in weight and length of 61.48 ± 8.40mg and 9.37 ± 1.68 mm, respectively, followed by fry fed B. plicatilis reared on I. galbana (43.56 ± 8.35mg and 6.25 ± 0.48mm). Milkfish fry fed B. plicatilis cultured on Chlorella sp. gave the poorest growth with mean gains in weight and length of 11.05 ± 1.82mg and 2.33 ± 0.29mm, respectively. Percentage survival ranged from 93.1 to 95.3 percent and was not significantly different between treatments (P < 0.05).

      The differences in population growth of B. plicatilis and consequently growth of milkfish fry was almost certainly attributed to the differences observed in the biological values of their algal diet, and in particular their protein and lipid contents. T. tetrahele and I. galbana improved the food value of B. plicatilis as live food for the milkfish fry. Their high dietary value was related to the higher algal protein and fat levels and contents of n-3 HUFA particularly 20:5n-3 and 22:6n-3 compared to B. plicatilis cultured on Chlorella sp. The results of the present study point to T. tetrahele as the most suitable food for the mass culture of the rotifer, B. plicatilis.
    • Article

      International study on Artemia. XXV. Factors determining the nutritional effectiveness of Artemia: The relative impact of chlorinated hydrocarbons and essential fatty acids in San Francisco Bay and San Pablo Bay Artemia 

      P Léger, P Sorgeloos, OM Millamena & KL Simpson - Journal of Experimental Marine Biology and Ecology, 1985 - Elsevier
      Different Artemia cyst samples harvested from the San Francisco and the San Pablo Bay regions (California, U.S.A.), and suspect because of their poor nutritional performance in fish and crustacean farming, have been analysed for their chlorinated hydrocarbon and fatty acid content. These results have been correlated with survival, growth, and biomass production of larvae of the marine crustacean Mysidopsisbahia Molenock fed those different Artemia in a standard culture test. Differences in chlorinated hydrocarbon content do not correlate with differences in mysid culture performance. Fatty acid profiles reveal three groups of Artemia batches with high, intermediate, and low levels of the highly unsaturated fatty acid 20:5ω3. The production yield of the mysid larvae could be correlated with the relative level of the 20:5ω3 fatty acid in the Artemia nauplii.
    • Book chapter

      Introduction to nutrition in tropical aquaculture 

      OM Millamena - In OM Millamena, RM Coloso & FP Pascual (Eds.), Nutrition in Tropical Aquaculture: Essentials of fish nutrition, feeds, and feeding of tropical aquatic species, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fish is a vital component of food security especially in developing countries of the world. As the world population grows, the need for more food and more fish has correspondingly increased. Aquaculture, the farming and husbandry of fish and other aquatic organisms, is now a well-established industry worldwide and is the fastest growing food production sector. However, as aquaculture operations expand, the risk to the environment grows.

      Fish nutrition and feeding play important roles in the sustainable development of aquaculture. The efficient conversion of feed to fish is important to fish farmers because feed is the largest component of the total cost of production. Improved feed composition and better feed efficiency will result in higher fish production, lower feed cost, and low waste production hence, decreased nutrient load from fish farming.
    • Article

      Low-cost feed for Penaeus monodon reared in tanks and under semi-intensive and intensive conditions in brackishwater ponds 

      OM Millamena & AT Triño - Aquaculture, 1997 - Elsevier
      Experimental diets for juvenile Penaeus monodon were formulated incorporating inexpensive indigenous raw materials. Local fish meal and cowpea meal were tested as replacements for imported protein sources and the diets did not contain vitamin and mineral premixes as supplements. Their effect on shrimp growth, survival, and feed conversion ratio were assessed under laboratory conditions. Best weight gain, specific growth rate, and feed conversion ratio were obtained in the diet with 75% replacement of protein from imported fish meal with local fish meal. This diet was field-tested in brackishwater ponds at three stocking densities: 5, 10, and 20 shrimp m−2. Results of two experimental runs in ponds showed that shrimp growth and survival was best at the lowest stocking density (5 m−2) and poorest at the highest stocking density (20 m−2) when 3% of shrimp became soft-shelled. Net pond production for 2 crops ha−1 year−1 were 1.87, 2.58, and 3.66 t ha−1 at 5, 10, and 20 m−2 stocking density. Cost-benefit analysis revealed a net return on investment (ROI) of 133, 58, 26% and payback periods of 0.7, 1.6, 4.0 years at stocking densities of 5, 10, 20 m−2, respectively. The low-cost feed, valued at P17 (US$0.70) kg−1, can effectively support pond production of P. monodon at a stocking rate of 5–10 m−2.
    • Article

      The macronutrient composition of natural food organisms mass cultured as larval feed for fish and prawns 

      OM Millamena, VD Peñaflorida & PF Subosa - The Israeli Journal of Aquaculture-Bamidgeh, 1990 - Society of Israeli Aquaculture and Marine Biotechnology
      The macronutrient composition of natural food organisms that are mass cultured as feed for the larval stages of fish and prawns in the SEAFDEC Aquaculture Department was determined by chemical analysis. The food organisms included five species of marine phytoplanktons (algae): Chaetoceros calcitrans, Skeletonema costatum, Tetraselmis chui, Chlorella vulgaris and Isochrysis galbana, and two zooplanktons: Artemia sp. nauplii (San Francisco Bay strain) and Brachionus plicatilis. The algal species were grown in batches on Guillard and Ryther media and harvested during the exponential phase of growth using a procedure which preserved cellular integrity and prevented cell lysis. The zooplankton were cultured using standard techniques adopted at the SEAFDEC Larval Food Laboratory. Each species was analyzed for proximate composition (protein, fat, fiber and ash) and for mineral content (calcium and phosphorous). Nitrogen-free extract (NFE) was determined by difference. For the five algal species, the protein, fat and NFE contents varied from 22% to 48%, 2% to 16% and 14% to 24%, respectively. The zooplanktons had higher protein and fat contents than any of the phytoplankton species except I. galbana which had the highest fat content. On the other hand, the phytoplanktons, particularly the diatoms which have a siliceous cell wall, contained significantly higher quantities of inorganic matter (ash). C. vulgaris had the highest fiber content which may be attributed to its cellulosic cell wall.