Now showing items 1-20 of 85

    • Article

      Acute nitrite toxicity and methemoglobinemia in juvenile milkfish (Chanos chanos Forsskal) 

      JME Almendras - Aquaculture, 1987 - Elsevier
      Nitrite was about 55 times more toxic to milkfish juveniles in fresh water than in 16% brackish water: the 48-h median lethal concentrations were 12 mg NO2-N/l (95% confidence limit=7.4–19.6) and 675 mg NO2-N/l (95% confidence limit = 435.8–1,045.4) respectively. Methemoglobin levels were higher for a given concentration of nitrite in milkfish kept in fresh water than in the brackish water. Methemoglobin decreased to a normal level within 24–26 hours of the removal of nitrite.
    • Article

      Aflatoxin B1 contamination of shrimp feeds and its effect on growth and hepatopancreas of pre-adult Penaeus monodon 

      MN Bautista, CR Lavilla-Pitogo, PF Subosa & ET Begino - Journal of the Science of Food and Agriculture, 1994 - Society of Chemical Industry
      A survey of aflatoxin B1 (AFLB1) levels in commonly used commercial shrimp finisher feeds in the Philippines showed a various range of values from not detected to 120 μg kg−1 using high-performance thin-layer chromatography. Six experimental diets were prepared to contain various levels of AFLB1 based on survey results to determine the effects of such contamination in pre-adult shrimp Penaeus monodon (17.5 ± 0.6 g). Results showed that shrimps fed diets containing AFLB1 greater than or equal to 73.8 μg kg−1 gave comparatively poor growth rate and higher susceptibility to shell diseases. No AFLB1 residues were detected in sampled whole shrimp tissues after 62 days of exposure to AFLB1 containing diets indicating a low potential for transmission of the toxin from edible shrimp tissues to consumers. Histopathological alterations in the hepatopancreas of shrimp chronically exposed to AFLB, were observed in all samples. The degree of alterations correlated with the level of AFLB1. Based on growth performance, pre-adult shrimps can tolerate AFLB1 levels of up to 52.3 μg kg−1 in the feeds although histopathological changes were already evident in the tissues of shrimps given diets with 26.5 μg kg−1 AFLB1.
    • Article

      Apparent digestibility of selected ingredients in diets for juvenile grouper, Epinephelus coioides (Hamilton) 

      PS Eusebio, RM Coloso & REP Mamauag - Aquaculture Research, 2004 - Blackwell Publishing
      Apparent digestibility coefficients (ADCs) for dry matter (ADCdm) and crude protein (ADCcp) of selected feed ingredients were determined in vivo for grouper using passive faeces collection (Guelph System). A reference diet (RF) and test diets (consisted of 70% RF and 30% test ingredient) with 1% Cr2O3 as an inert indicator were used. An RF contained 45% protein, 10% fat and 15.7 kJ g−1 metabolizable energy. Three isonitrogenous and isocaloric diets, each contained a test ingredient (white fish meal, white cowpea meal and ipil-ipil leaf meal), were used in a growth study based on ADCcp of feed ingredients. An RF without Cr2O3 was a control. The ADC values of experimental diets were also determined. In grouper, the ADCdm of white cowpea meal, defatted soybean meal, wheat flour and shrimp meal (74–76%) were significantly lower than that of squid meal (99%), but comparable with those of the fish meals (84–89%). No significant difference was observed between the ADCdm of ipil-ipil leaf meal, rice bran and wheat flour (56–73%). The ADCcp of white cowpea meal and defatted soybean meal were similar to those of the fish meals, squid meal and shrimp meal (94–99%). The ADCcp of wheat flour was comparable with that of ipil-ipil leaf meal (79–83%). Rice bran had the lowest ADCcp value of 43%. Based on specific growth rate (SGR), the growth of fish fed white cowpea meal-based diets was similar to that of the control fish (3.2–3.3% day−1). Also, no significant difference was observed between the ADCdm (68–72%) and ADCcp (88–91%) of white cowpea meal-based diet and the control diet. The results suggest that ADC values can be used as indicators to determine the nutritional value of feed ingredients. White cowpea meal can be incorporated as a protein source in practical diet for grouper at 20.5% of the diet with no adverse effect on growth.
    • Article

      Arginine and threonine requirements of milkfish (Chanos chanos Forsskal) juveniles 

      IG Borlongan - Aquaculture, 1991 - Elsevier
      Growth studies were conducted with milkfish (Chanos chanos Forsskal) juveniles to determine the quantitative requirements for arginine and threonine. The amino-acid test diets (40% crude protein) contained casein and gelatin supplemented with crystalline L-amino acids to provide an amino-acid profile similar to milkfish protein except for the test amino acid. Each set of experimental diets consisted of six isonitrogenous and isocaloric diets containing graded levels of the essential amino acid to be tested. Break-points in the growth curves which represent the optimum dietary concentration of arginine and threonine for fish growth were determined by the broken-line regression method. Based on dry diet, the requirement of milkfish juveniles for arginine is 2.10% and for threonine, 1.80%. These values correspond to 5.25% arginine and 4.50% threonine when expressed as a percentage of dietary protein.
    • Book

      Biology and hatchery of mangrove crabs Scylla spp. 

      ET Quinitio, FD Parado-Estepa & JJ dela Cruz-Huervana - 2018 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 34
      This manual includes the biology of crab (Scylla serrata, S. tranquebarica, and S. olivacea), and describes principles and procedures for spawning the mature crabs and rearing the zoea to ‘fly’ size crabs. It focuses on the hatchery rearing of S. serrata as the farming of this species is more economically viable than the two other species. The techniques may be modified depending on the conditions or problems encountered in a specific site.
    • Book

      Biology and hatchery of mud crabs Scylla spp. 

      ET Quinitio & FD Parado-Estepa - 2008 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 34
      This manual includes the biology of mud crab, and describes principles and procedures for spawning the mature crabs (Scylla serrata, S. tranquebarica, and S. olivacea) and rearing the zoea to fly size crabs. It focuses on the hatchery rearing of S. serrata as this species is more economically viable than the two other species. The techniques may be modified depending on the conditions or problems encountered in a specific site.
    • Book

      Biology and hatchery of mud crabs Scylla spp. 

      ET Quinitio & FD Parado-Estepa - 2003 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 34
      This manual describes the principles and procedures for spawning the mature crabs (Scylla serrata, S. tranquebarica, and S. olivacea) and rearing the zoeae to juveniles. Hatchery conditions should satisfy the ecological requirements of each specific stage, thus the manual starts with a section on biology of mud crabs.
    • 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 paper

      Development of immunostimulant for mud crab, Scylla serrata 

      RF Traifalgar - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Non-specific immune activitation is considered a potential prophylactic approach in the prevention of disease outbreaks in crustacean aquaculture. The present investigation evaluates the dietary supplementation of bacterial and algal derived immunostimulants including peptidoglycan, ergosan, mannan oligosaccharide and acidic polysaccharides from Ulva, Sargassum and Padina to enhance the immunological responses and resistance of Scylla serrata juveniles against white spot syndrome virus (WSSV) infection. Each of the test immunostimulant was optimized for dose and frequency of administration.

      Results showed significant enhancement of shrimp survival against WSSV infection if Mannan oligosaccharide is supplemented at 2000 mg kg-1 diet applied every 3 days. Optimum dose and frequency of application for peptidoglycan was determined as 1000 mg kg-1 diet applied every 3 days while a dose of 2000 mg kg-1 diet applied every 3 days was found optimum for ergosan. Enhancement of survival was also observed in crabs given the acidic polysaccharide extracts from seaweeds. Better survival was observed in the treatment receiving Ulva at 1000 mg kg-1 applied every 3 days. Similar dose and frequency were also observed to enhance the resistance of the juvenile crabs against WSSV when maintained with diets supplemented with Padina and Sargassum acidic polysaccharides. The high survival in these treatments is associated with the prominent enhancement of immunological responses including phenol oxidase activity, respiratory burst and total hemocyte counts. At optimum dosage and application frequency, these immunostimulants are observed to improve overall growth performance of the juvenile crab. These results suggest that dietary supplementation of peptidoglycan, ergosan mannan oligosaccharide, and acidic polysaccharides from Ulva, Sargassum and Padina at a dose described above can be used to boost the immunological response and enhance the resistance of S. serrata juveniles against WSSV infection.
    • 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

      Dietary requirement of milkfish (Chanos chanos Forsskal) juveniles for total aromatic amino acids 

      IG Borlongan - Aquaculture, 1992 - Elsevier
      The phenylalanine requirement of milkfish at two dietary tyrosine levels was determined using a 2× 6 factorial feeding experiment. The amino acid test diets (45% crude protein) contained vitamin-free casein and gelatin supplemented with crystalline L-amino acids to provide an amino acid profile similar to milkfish tissue protein except for the test amino acid. The experimental diets consisted of 12 isonitrogenous and isocaloric diets containing six graded levels of phenylalanine (1.18, 1.3, 1.6, 1.9, 2.2, and 2.5% of dry diet) at two levels of tyrosine (0.45 and 1.2% of dry diet). Each of the 12 diets was fed to triplicate groups of 15 milkfish juveniles (initial mean weight = 0.58 ± 003 g) for 12 weeks.

      Breakpoint linear regression analysis of the growth data estimated the phenylalanine requirement to be 1.90% of the dry diet (4.22% of dietary protein) at 0.45% dietary tyrosine. In the presence of 1.2% dietary tyrosine, the phenylalanine requirement was estimated to be 1.26% of the dry diet (2.80% of dietary protein), suggesting that tyrosine can supply a portion of the total aromatic amino acid requirement thereby sparing phenylalanine. The optimum total aromatic amino acid requirement of milkfish obtained in the study was 5.22% of dietary protein and the replacement value of tyrosine for phenylalanine was computed to be about 46%. Total aromatic amino acid levels higher than 6.88% caused a significant depression of growth in milkfish juveniles.
    • Article

      Dietary soy peptide enhances thermotolerance and survival of juvenile japanese flounder, Paralichthys olivaceus 

      JA Ragaza, REP Mamauag, S Yokoyama, M Ishikawa & S Koshio - Journal of the World Aquaculture Society, 2015 - World Aquaculture Society
      Soy peptide (SP), a soy protein enzymatic hydrolysate, contains bioactive substances that could be utilized as an immune-stimulating feed ingredient. The experiment evaluated the efficacy of dietary SP on promoting growth, and enhancing tolerance and survival to heat stress in juvenile Japanese flounder, Paralichthys olivaceus. Four diets were incorporated with different levels of SP (0, 2, 5, and 10%) and a 6-wk feeding trial ensued. Following the feeding trial, the experimental groups were subjected to heat stress to measure survival rate and heat shock protein 70s (HSP70s) in gill, liver, and skin. Fish fed diets with SP inclusion showed considerable decrease in percent weight gain. Significantly higher lethal time values to 50% mortality (LT50) value were recorded for fish fed 10% SP. Moreover, LT50 values of fish fed 2 and 5% SP were significantly higher compared with fish fed control diet. HSP70s produced in all the tissues were significantly highest in fish fed 10% SP. HSP70s values were significantly higher in fish fed 2 and 5% SP compared with fish fed control diet. A significant reduction in HSP70s among all groups during recovery period was also observed. These results suggest that SP can be used to enhance the immune response and survival of P. olivaceus under heat stress.
    • Article

      Effect of dietary organic acid salts, potassium diformate and sodium diformate on the growth performance of male Nile tilapia Oreochromis niloticus 

      MLA Cuvin-Aralar, C Luckstaedt, K Schroeder & KJ Kühlmann - Bulletin of Fish Biology, 2011 - Verlag Natur & Wissenschaft
      The effect of two organic acid salts on the production performance of juvenile male Nile tilapia Oreochromis niloticus were studied in two separate experiments. In the first trial the fish (initial size: 7.84kg) were fed commercial feed supplemented with 0,3% potassium diformate (KDF) while in the second trial the fish (initial size: 16.48 kg) were fed diets supplemented with 0,3% sodium diformate (NDF). The control group for both trials used the same commercial fish feed with no supplementation. The feeding trials lasted for 74 and 78 days, respectively. Results showed that the supplementation of either KDF or NDF significantly improved growth and feed conversion of male Nile tilapia compared to the control group. The fish in the KDF treatment had a mean final weight of 51.4g and FCR of 1.81 compared to 45.4g and 1.97, respectively, for the control. Mean final weight and FCR of fish in the NDF treatment were 66.2g and 0.69, respectively, while those of the control were 58.7g and 0.77. The condition factor of the fish in both trials was not affected by treatment.
    • Article

      Effect of juvenile hormone and serotonin (5-HT) on mixis induction of the rotifer Brachionus plicatilis Muller 

      WG Gallardo, A Hagiwara & TW Snell - Journal of Experimental Marine Biology and Ecology, 2000 - Elsevier
      Juvenile hormone (JH) and serotonin (5-HT) were previously shown to enhance mictic (sexual) female production of the rotifer Brachionus plicatilis in batch cultures. To explore the basis of these effects, experiments were conducted on isolated individuals. JH treatment of maternal rotifers with 5 and 50 µg ml-1 (18.8 and 187.7 µM) resulted in significantly higher (P < 0.05) mictic female production in the second (F2) and third (F3) generations. JH treatment was effective even at a lower food concentration of 7 × 105 cells ml, but it was not effective when free ammonia was added at 2.4 and 3.1 µg ml-1. Mictic female production was not increased with exposure to 5-HT up to 50 µg ml-1 (129.1 µM) concentrations. When food level was reduced to 7 × 105 cells ml-1, however, 5-HT-treated rotifers produced significantly (P < 0.05) more mictic females than the control, particularly in F3 generation. Mictic female production of 5-HT-treated rotifers did not differ from that of the control with or without free ammonia, but the intrinsic rate of natural increase (r) of 5-HT-treated rotifers at 3.1 µg ml-1 free ammonia was significantly higher than the control. These results show that juvenile hormone increases mictic female production under optimum and sub-optimum food levels, whereas 5-HT increases both mictic female production at low food level and population growth rate at high free ammonia concentrations. These compounds could be used to manage rotifer cultures and probe the mechanisms controlling the rotifer life cycle as it switches to mictic reproduction.
    • Article

      Effect of rotenone and saponin on the shell quality of juvenile tiger shrimp, Penaeus monodon 

      ER Cruz-Lacierda - The Israeli Journal of Aquaculture-Bamidgeh, 1993 - Society of Israeli Aquaculture and Marine Biotechnology
      Tiger shrimp (Penaeus monodon) juveniles were exposed to varying concentrations of rotenone and saponin to determine their effects on survival and shell quality. The highest concentrations tested, 50 ppm rotenone and 100 ppm saponin, were not lethal to shrimp. Shrimps exposed to 0.001 to 50 ppm rotenone had 7.4-66.6% shell softening while shrimps exposed to 0.001 to 100 ppm saponin had 2.66-66.6% shell softening. The shell softening rates were significantly higher in 1.0 to 50 ppm rotenone and 100 ppm saponin than in control shrimps.
    • Article

      Effect of salinity on survival of Metapenaeus anchistus juveniles and subadults 

      MJHL Lebata & J Primavera - UPV Journal of Natural Sciences, 1997 - University of the Philippines in the Visayas
      Survival of Metapenaeus anchistus (De Man) juveniles and subadults at 5, 15, 25, 35 (control) and 45 ppt salinity levels was determined and compared. Salinity levels lower than 35 ppt level were prepared by diluting pure seawater with tap water (OPPT) while 45 ppt level was prepared by diluting 85 ppt water with tap water. Survival was observed at 0.5, 1, 2, 3, 6, 12, 18, 24 h after stocking and every 12 hours thereafter until 96 h.

      Shrimp survival was highest at 35 ppt (P<0.01); differences among treatments were first observed at 2 h after exposure with some shrimps dying at 5 ppt. At the end of the experiment, survival was highest at 35 ppt (100%), followed by 25 and 45 ppt (90 and 80%, respectively), 15 ppt (50%) and 5 ppt (0%).
    • Article

      Effect of streamer tags on survival and growth of juvenile tiger prawns, Penaeus monodon, under laboratory conditions 

      JH Primavera & RM Caballero - Marine and Freshwater Research, 1992 - CSIRO Publishing
      The effects of streamer tags and initial prawn size on survival and growth in 2-month- and 7-month-old pond-reared juveniles of Penaeus monodon Fabricius (11-30 mm carapace length, CL) were assessed under laboratory conditions. Tagging did not cause immediate mortality in juveniles of 11-21 mm CL within a one-week period but led to a significantly lower survival rate after 6 to 8 weeks in 1-m3 tanks. However, tagged prawns of 21-30 mm CL showed high long-term survival rates up to 90% in a 12-m3 tank. The 2-month-old juveniles had lower survival rates than 7-month-old prawns. Specific growth rate was not affected by tagging but was significantly higher in smaller prawns. In general, there was no interaction between the effects of tagging and prawn size in terms of growth and survival rates.

      The lower long-term survival rate associated with tags may be due to the attractiveness of tags to predators, or to trauma or stress caused by the weight of the tags. These factors are discussed in relation to findings for other penaeid species.
    • Article

      The essential fatty acid requirement of milkfish (Chanos chanos Forsskal) 

      IG Borlongan - Fish Physiology and Biochemistry, 1992 - Springer Verlag
      The essential fatty acid (EFA) requirement of milkfish was examined by a 12-week feeding trial using defined, purified diets at water temperature of 28–29°C and salinity of 32‰. The test diets contained varying levels of 18:0 (triglyceride form, TG), 18:3(n−3), 18:2(n−6) and (n−3) highly unsaturated fatty acids (n−3 HUFA). Milkfish juveniles were starved for 7 days and were than fed lipid-free diet for 30 days before the initiation of feeding trials. Low growth and feed efficiency together with high mortalities were observed in fish fed the lipid-free diet as well as in the EFA-deficient diet. Supplementation of 2% 18:2(n−6) to the tristearin based diet did not improve growth rate of milkfish as effectively as feeding with (n−3) fatty acids. The highest weight gain was obtained in milkfish fed a combination of 5% 18:0 + 1.0% 18:3(n−3) + 0.5% 20:5(n−3) + 0.5% 22:6(n−3) although the supplementation of 2% 18:3(n−3) alone or combination of 0.5% 20:5(n−3) + 0.5% 22:6(n−3) to the tristearin based diets were also effective for improvement of growth. Thus, (n−3) fatty acids, such as 18:3(n−3) and (n−3)HUFA were nutritionally more important than 18:2(n−6) for milkfish. The fatty acid composition of the polar lipids from whole body of milkfish juveniles fed the various test diets were influenced by the composition of the dietary fatty acids.
    • magazineArticle

      European Union's special project on mudcrab 

      Southeast Asian Fisheries Development Center, Aquaculture Department - SEAFDEC Asian Aquaculture, 2003 - Aquaculture Department, Southeast Asian Fisheries Development Center