Now showing items 1-15 of 15

    • Article

      Attractants in purified diets 

      FP Pascual - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Juvenile Penaeus monodon were reared on purified diets containing different attractants used to gelatinize the cornstarch: plain water, shrimp, mussel, squid or trash fish extract. The highest survival rate was observed in the group given the shrimp attractant, followed by mussel, fish and squid. However growth appeared best in the diet containing mussel extract. Mussel extract apparently can be used to enhance the attractability of purified diets.
    • Article

      Carbohydrate requirements of Penaeus monodon (Fabricius) juveniles 

      VR Alava & FP Pascual - Aquaculture, 1987 - Elsevier
      P. monodon juveniles with an initial mean weight of 0.62 g were fed isonitrogenous (45%) and isolipidic (10%) semi-purified diets containing 10, 20 and 30% trehalose, sucrose and glucose for 56 days. Shrimp fed the diet with 20% trehalose had the highest weight gain. Of the three types of sugar tested, shrimp fed diets containing trehalose and sucrose exhibited better weight gains than those fed glucose diets. A dietary sugar level of 20% resulted in the best weight gain whereas the 30% level gave the lowest weight gain.

      The survival of shrimp was also affected by the type of carbohydrate fed. Trehalose and sucrose diets promoted higher survival rates than glucose diets. The different types and levels of carbohydrates showed combined effects on the dry matter percentages of crude protein and total lipid. Trehalose and sucrose diets generally promoted increased protein deposition. Trehalose at 30% and sucrose at 20% depressed lipid content.
    • Conference poster

      Carbohydrate requirements of Penaeus monodon juveniles. 

      VR Alava & FP Pascual - In Y Taki, JH Primavera & JA Llobrera (Eds.), Proceedings of the First International Conference on the Culture of Penaeid Prawns/Shrimps, 4-7 December 1984, Iloilo City, Philippines, 1985 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Penaeus monodon juveniles (initial mean weight=0.62 g) were fed semi-purified diets containing 10, 20 and 30% trehalose, sucrose or glucose for eight weeks. Results showed that shrimps fed 20% trehalose gave the highest growth rate. Of the three types of sugars tested, trehalose promoted the best growth rates, followed by sucrose and glucose. When the level of sugar was considered, 20% gave the best growth rate and 30%, the lowest. The type as well as level of sugar greatly affected the body crude protein and body lipid (P < 0.01), while survival was mainly affected by type of sugar alone (P < 0.01). Trehalose and sucrose diets promoted better survival than glucose diets. A negative linear correlation (r = —0.70) between the body crude protein and body lipid was obtained.
    • Article

      Early effects of nutritional stress on the liver of milkfish, Chanos chanos (Forsskal), and on the hepatopancreas of the tiger prawn, Penaeus monodon (Fabricius) 

      V Storch, JV Juario & FP Pascual - Aquaculture, 1984 - Elsevier
      After periods of food deprivation and subsequent feeding, hepatocytes of Chanos chanos fry and R-cells of Penaeus monodon juveniles were investigated by means of transmission electron microscope. They clearly reflect the quality of different diets and thus can be used as monitor cells. For purposes of comparison, the same diets were offered to land-dwelling isopods which are known to accept a variety of different diets. Thus, this technique could also be used as a method of determining the effectiveness of binders in artificial diets.
    • Book

      Feeding prawns for grow-out culture 

      FP Pascual & RV Rivera - 1989 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension pamphlet / SEAFDEC. Aquaculture Department; No. 2
    • Article

      Gum arabic, carrageenan of various types and sago palm starch as binders in prawn diets 

      FP Pascual & A Sumalangcay - Fisheries Research Journal of the Philippines, 1982 - Fisheries Research Society of the Philippines
      Sago palm starch, gum arabic and three types of carrageenan (EPT-2, St-0008-29 & St-008-30A) were tried as binders in a practical diet. EPT-2 carrageenan gave consistently better water stability than the other binders in both steamed and unsteamed pellets after 24 hours. Although water stability of the unsteamed pellets was lower than steamed pellets, those made with EPT-2 had higher water stability (53.4%) than those prepared with the other binders.
    • Conference paper

      Interaction of the midgut gland and the ovary in vitellogenesis and consequences for the breeding success: a comparison of unablated and ablated spawners of Penaeus monodon 

      G Vogt, ET Quinitio & FP Pascual - In N De Pauw, E Jaspers, H Ackefors & N Wilkins (Eds.), Aquaculture - A Biotechnology in Progress. Proceedings of the International Conference Aquaculture Europe '87, Amsterdam, The Netherlands, June 2-5, 1987, 1989 - European Aquaculture Society
      The midgut glands and ovaries of unablated and ablated females of Penaeus monodon were examined before and after spawning by light and electron microscopy to elucidate the role of the midgut gland during vitellogenesis. In addition, the larvae of both were divided into fed and starved groups and the mortalities were recorded up to stage postlarva 5 in order to compare the quality of the offspring from unablated and ablated spawners. Although a limited number of spawners was used in this preliminary study, a close interaction of the midgut gland and the ovary during vitellogenesis is evident. The influence of eyestalk ablation on the breeding success is discussed and hypothetically correlated to endocrinology. In late vitellogenesis, the resorptive cells of the midgut gland of an unablated female exhibited specific ultrastructural characteristics such as whirls of rough endoplasmic reticulum, conspicuous Golgi bodies and highly active smooth endoplasmic reticulum. The ablate these features only in moderate development. After spawning, the normal structures of the midgut gland cells were restored to a large extent. In the ovary of the unablated female before spawning, mature oocytes were dominant. After spawning, the ovary of the unablated female contained only immature oocytes. In contrast, all stages of maturation could be found in the ablated female 2h after spawning. The hatching rate was much lower in the ablated female. Up to stage postlarva 5, however, fed larvae from the ablated and unablated spawners had the same mortality rates. Starved zoea 1 from both types of spawners could not reach the next moulting stage without feeding. This indicates the urgent necessity of good feed at the very beginning of larval development. When the larvae were fed until moulting to mysis and then starved during mysis stage, the offspring of the ablated spawner died earlier than that of the unablated female. Only a very few starved larvae reached the postlarval stage. In any case, starvation led to an extension of the various larval stages and substages.
    • Article

      Leucaena leucocephala leaves in formulated feed for Penaeus monodon: a concrete example of the application of histology in nutrition research 

      G Vogt, ET Quinitio & FP Pascual - Aquaculture, 1986 - Elsevier
      Penaeus monodon postlarvae were fed with formulated diets containing either soaked or unsoaked Leucaena leaves. A similarly prepared feed with soybean in place of Leucaena was used for comparison. Results were analysed by statistical and histological methods.

      Results of the 4-week feeding experiment showed that mean weight gains and percentage survival of the prawns fed with the two Leucaena-containing diets were higher, but not significantly different from soybean-containing diet. The content of the poisonous amino acid mimosine in the Leucaena leaves could be reduced about 70% by soaking the leaves in freshwater for 24 h. Highest weight gain was obtained with the feed containing these soaked leaves.

      In addition to growth and survival, the R-cells of the midgut glands of the postlarvae were investigated by light and electron microscopy. Although the statistical growth values and the proximate analyses of the test diets were similar, a food-specific ultrastructure was established after only 4 days of feeding. All diets resulted in subcellular characteristics typical for well fed prawns and, at that time, the Leucaena diets were already slightly superior to the soybean control. This indicates that different sources of macronutrients lead to different ultrastructures even if the proximate analyses of protein, carbohydrate and lipid are similar.

      Only slight changes in the R-cells were observed after 11, 20 and 28 days in the prawns fed with the soybean diet compared to 4 days of feeding. In the diet containing unsoaked Leucaena leaves, however, many R-cells became heavily damaged after 20 and 28 days, whereas the prawns fed with the diet containing soaked leaves exhibited less pronounced distortion. Statistical analyses of growth and survival rate did not show these adverse effects at that time. Although it is highly probable that the mimosine is responsible for those pathological symptoms, complementary experiments could not clearly prove that.

      The effects of feed components are visible on the cellular or organ level after only a few days, whereas the individuals (organism level) reflect them about 10 days later. Another 10 days later the changes are manifested in the population. Therefore it is suggested to use histology in nutrition studies as a supplementary source of information to statistical and biochemical parameters. The midgut glands can further be used to monitor the nutritional condition of prawns in aquaculture, sea ranching, and in ecological investigations.

      The study confirms that Leucaena leaves are a promising protein source for prawn diets if mimosine could be reduced to a very low level. A mimosine level of 0.25% in the feed is still too high, if the diet is used uninterruptedly for several weeks.
    • Article

      Midgut gland as monitor organ for the nutritional value of diets in Penaeus monodon (Decapoda) 

      G Vogt, V Storch, ET Quinitio & FP Pascual - Aquaculture, 1985 - Elsevier
      Midgut gland cells of Penaeus monodon postlarvae were investigated by electron microscopy after starvation and refeeding with different diets.

      Well nourished postlarvae could be starved for 5 days without irreversible detriment. They recovered easily on a good diet. Only R cells were affected by a short starvation period. After 13 days of food deprivation the structures of all cell types were disintegrated. The postlarvae were able to starve for a maximum of 15 days. The most diversified ultrastructure was obtained by refeeding with cod liver oil and 2s (mixed diet). Casein was not well utilized. Sucrose was the poorest diet. The midgut gland of Penaeus monodon seems to be lipid oriented. Only fat was used as storage material; glycogen was lacking.

      Different ultrastructures were induced in R cells by a given diet after longer starvation periods. The reestablishment of their ultrastructure by means of a definite diet seems to be impossible after a certain period of starvation (point of no return).

      R cells are very sensitive to different diets. B cells show slight reactions, while F and E cells remain relatively unchanged. This indicates that R cells could be used to monitor the nutritional value of prawn diets in aquaculture.
    • Book

      Nutrition and feeding of Penaeus monodon 

      FP Pascual - 1989 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 3
      Following an account of the feeding habits and nutritional needs of Penaeus monodon, diet formulation for cultured shrimp is discussed in detail. Equipment required, preparation of the diets and methods of feeding are detailed.
    • Article

      A practical method of extracting mimosine from ipil-ipil, Leucaena leucocephala, leaves and its effect on survival and growth of Penaeus monodon juveniles 

      VD Peñaflorida, FP Pascual & NS Tabbu - The Israeli Journal of Aquaculture-Bamidgeh, 1992 - Society of Israeli Aquaculture and Marine Biotechnology
      Soaking fresh ipil-ipil, Leucaena leucocephala, leaves in tap water (1:1, v/v; or 50 g in 500 ml) for 30-48 hours with a water change after 24 hours extract atleast 90% of its mimosine, a toxic lysine derivative. This extraction procedure is more economical and practical for fish farmers than the use of dry or moist heat or iron compounds.

      Soaked or unsoaked leaves of Peruvian or Hawaiian ipil-ipil Leucaena leucocephala formed 1/3 of trial diets fed to Penaeus monodon juveniles (1-2 g). Other protein sources consisted of fish and shrimp-head meals. A diet without ipil-ipil leaves (FS) served as the control.

      After 8 weeks, the mass weight of shrimp fed the FS and soaked Hawaiian leaf diets (HLS) was significantly (α= 0.05) higher than soaked (PLS) and unsoaked (PLU) Peruvian leaves. The HLS group had a significantly higher survival rate than the PLS and PLU groups but not the FS-fed shrimps; survival among shrimp fed unsoaked Hawaiian leaves (HLU) was zero.

      It was found that the Hawaiian variety of ipil-ipil leaves when soaked for 24 hours can be incorporated in the P. monodon juvenile diet with good survival (87%) under laboratory conditions. However, the optimum amount of leaves to be included in a low cost and efficient diet has yet to be determined.
    • Article

      A preliminary study on the protein requirements of Chanos chanos (Forskal) fry in a controlled environment 

      C Lim, S Sukhawongs & FP Pascual - Aquaculture, 1979 - Elsevier
      Milkfish (Chanos chanos) fry with an average weight of 40 mg per fish were stocked in 60-l wooden-glass aquaria filled with 30 l of filtered sea water with a salinity of 32–34 p.p.t. and a temperature of 25–28°C. They were fed diets containing 20, 30, 40, 50 and 60% protein and 2740 kcal of digestible energy per kg at a daily rate of 10% of the biomass for a period of 30 days. Fish which were fed the diet containing 40% protein had the highest weight gain which was significantly higher (P < 0.05) than those of fish receiving the lower dietary levels of protein. Slightly lower weight gains were obtained when fish were fed diets containing 50 and 60% protein. Although feed conversion values were not statistically different (P < 0.05) among all treatments, the value for the 40% protein diet (1.96) was the best. The mean survival rates were low for all treatments but was highest for the 40% protein diet. No significant difference (P < 0.05) was found in the survival rates of fish receiving different treatments. Results show that a dietary level of 40% protein was required by milkfish fry for maximum growth, efficient feed conversion and high survival rate.
    • Article

      A preliminary study on the use of the local variety of ipil-ipil Leucaena leucocephala as a protein source for prawn feed 

      FP Pascual - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A study was carried out to determine the effect of 10 or 20% leaves or seeds in the diet of Penaeus monodon , and the extent to which local ipil-ipil (Leucaena leucocephala ) could replace head shrimp meal. A brief description is given of the experimental methodology, and details of composition of the diet, proximate chemical composition of the diets, mean weight gain and survival of Penaeus monodon larvae fed shrimp head meal and ipil-ipil as protein sources, are presented. Mean weight gains for all groups were poor and not statistically significant. Survival rates for those fed 10% ipil-ipil were significantly higher than those fed 20% diets. Wherever the survival rate was high, mean weight gain was low and vice versa. The presence of the toxic alkaloids mimosine in ipil-ipil could have caused the low survival rate.
    • Article

      Specific amino acid-free semi-purified diets for Penaeus monodon juveniles 

      FP Pascual & A Kanazawa - Memoirs of the Kagoshima University Research Center for the South Pacific, 1986 - Kagoshima University Research Center for the South Pacific
      To determine the effects of deficiency of individual amino acids believed to be essential to Penaeus monodon juveniles, a 28-day feeding experiment was carried out with P. monodon postlarvae.

      P. monodon postlarvae weighing around 120 mg each were randomly distributed in individual perforated one liter jars, 10 jars in 60-liter, fiberglass tanks, in a flow through seawater system, which passed through a 0.35 micron filter before use. Animals were reared in these jars for 28 days on semi-purified moist diets. Salinity and temperature ranged from 27 to 32 ppt and 26 to 28.9°C, respectively.

      Percentage weight gains and survival rates were not significantly different among test diets. However, some amino acids seemed to be more critical than others in the diets. Animals given phenylalanine-free, leucine-free, and methionine-free diets gained more than 300% compared to those fed the complete amino acid diets. A low weight gain of 228.6% was observed in animals fed arginine-free diet. Animals fed the histidine-free, lysine-free, threonine-free and valine-free diets also gained less than 200%. Survival rates were 60% for those given threonine-free and isoleucine-free diets, 70% for histidine-free and complete amino acid diets, whereas those fed the phenylalanine-free, leucine-free and methionine-free diets had survival of 80 to 85%. These results suggest the possibility that some amino acids were taken from sources outside the diets and could have corne from whatever bacterial growth there was in the rearing jars.
    • Article

      Tissue lipid content and fatty acid composition of Penaeus monodon Fabricius broodstock from the wild 

      OM Millamena & FP Pascual - Journal of the World Aquaculture Society, 1990 - Wiley-Blackwell
      Tissues (hepatopancreas, muscle, gonad) of wild Penacus mordon females with ovaries in different stages of development and males were analyzed for Upid content and fatty acid composition. Hepatopancreatic tissue had the highest mean levels of lipid at 15.72–25.20% in females and averaged 46.20 ± 1.53% in males. Levels of Lipid in the muscle were low with no marked variation throughout the maturation s-es. Ovarian lipid levels increased significantly at stage II (early maturing ovaries) and remained high through stage IV (fully mature ovaries). Peak lipid level was found at stage III (late maturing ovaries) and coincided with a decline in hepatopancreas lipid. Ovarian and hepatopancreatic lipids declined drastically in spent females. Profiles of fatty acid in the tissues consistently showed the presence of PUFA 204n-6, 20:5n-3 and 22611-3, with high levels in the polar lipid fraction of vitellogenic ovaries. These values were reflected in the male testis and spawned eggs. The finding suggest storage and utilization of lipids for maturation and spawning processes and that the phospholipids were mainly responsible for increases in ovarian lipids. The type of fatty acids present in maturing prawn ovaries is indicative of their importance in reproductive physiology.