Now showing items 21-40 of 1064

    • Article

      Agar-digesting bacteria associated with ‘rotten thallus syndrome’ of Gracilaria sp. 

      CR Lavilla-Pitogo - Aquaculture, 1992 - Elsevier
      A condition of the tetrasporophyte stage Gracilaria spp., characterized by white to pinkish discoloration and gradual disintegration of the thallus, has been observed in tank-held stocks. Microscopic observation revealed no fungal or protozoan parasites. Appropriate dilutions of homogenates plated on nutrient agar and bromthymol blue teepol agar showed the presence of bacteria, all of which were agar-digesting, at the rate of 1.42 × 107 cells per g of affected thalli. Colonies on bromthymol blue teepol agar were round and yellow, while those on nutrient agar appeared creamy and round with entire edges, and were rapid agar digesters. The bacteria were Gram negative, fermentative and motile rods. Based on biochemical characteristics, the isolates were classified as belonging to the genus Vibrio. Microscopic observations of thalli cross-sections showed erosion of the pericarp, thus revealing the cortical and the medullary cells. Scanning electron microscopy revealed rod-shaped bacteria, including dividing cells, in affected tissues. Antibiotic sensitivity tests indicated that the bacteria were sensitive to Polymyxin B, nalidixic acid, nitrofurazone and oxytetracycline.
    • Article

      Air breathing of aquatic burrow-dwelling eel goby, Odontamblyopus lacepedii (Gobiidae: Amblyopinae) 

      TT Gonzales, M Katoh & A Ishimatsu - Journal of Experimental Biology, 2006 - Company of Biologists
      Odontamblyopus lacepedii is an eel goby that inhabits both coastal waters and intertidal zones in East Asia, including Japan. The fish excavates burrows in mudflats but, unlike the sympatric amphibious mudskippers, it does not emerge but stays in the burrows filled with hypoxic water during low tide. Endoscopic observations of the field burrows demonstrated that the fish breathed air in the burrow opening; air breathing commenced 1.3 h following burrow emersion, when water PO2 was ∼2.8 kPa, with an air-breathing frequency (fAB) of 7.3±2.9 breaths h–1 (mean ± s.d., N=5). Laboratory experiments revealed that the fish is a facultative air breather. It never breathed air in normoxic water (PO2=20.7 kPa) but started bimodal respiration when water PO2 was reduced to 1.0–3.1 kPa. The fish held air inside the mouth and probably used the gills as gas-exchange surfaces since no rich vascularization occurred in the mouth linings. As is known for other air-breathing fishes, fAB increased with decreasing water PO2. Both buccal gas volume (VB) and inspired volume (VI) were significantly correlated with body mass (Mb). At a given Mb, VI was nearly always equal to VB, implying almost complete buccal gas renewal in every breathing cycle. A temporal reduction in expired volume (VE) was probably due to a low aerial gas exchange ratio (CO2 elimination/O2 uptake). Air breathing appears to have evolved in O. lacepedii as an adaptation to aquatic hypoxia in the burrows. The acquisition of the novel respiratory capacity enables this species to stay in the burrows during low tide and extends the resident time in the mudflat, thereby increasing its chances of tapping the rich resources of the area.
    • Article

      Algal production in wastewater: Progress and problems. 

      JB Pantastico - Ergebnisse der Limnologie, 1987 - E. Schweizerbartsche Verlagsbuchhandlung
      Algal production in wastewater is reviewed in two major areas: (1) production of single-cell proteins, and (2) its integration with aquaculture for the production of natural feeds. Progress achieved so far in the various aspects of algal production in the laboratory and outdoors are discussed, as are biotechnological problems in the operation and maintenance of high-rate algal ponds. The need for more basic and applied research is emphasized.
    • Article

      Amino acid profiles in the midgut, ovary, developing eggs and zoea of the mud crab, Scylla serrata 

      VD Peñaflorida - The Israeli Journal of Aquaculture-Bamidgeh, 2004 - Society of Israeli Aquaculture and Marine Biotechnology
      Culture of the mud crab, Scylla serrata, is beset by low and inconsistent survival of larvae in spite of the high fecundity of crab breeders. The nutrition of the embryo and pre-feeding zoea depends on what is stored in the egg. The protein and free amino acid contents of the midgut gland, ovary, eggs, pre-feeding zoea, live food and a maintenance diet for broodstock were analyzed by HPLC. The maintenance diet had lower arginine, histidine, methionine, threonine and tryptophan than the ovary and egg. The midgut had higher phenylalanine and valine and lower leucine, methionine and tryptophan than the ovary. Amino acid profiles in the ovary, egg and zoea showed that methionine was highest in the ovary and leucine was highest in the zoea. Low val- ues were observed for isoleucine and valine in ovary, arginine in egg, methionine and pheny- lalanine in zoea. When live foods were compared to zoea, histidine in Brachionus, leucine and tryptophan in Artemia, and arginine, leucine and valine in Acartia were low. Essential free amino acids in fertilized eggs were 2.5 times higher than in unfertilized eggs. Arginine, histidine, lysine, methionine, tyrosine and threonine decreased with egg embryogenesis, suggesting that these are the major free amino acids utilized as the egg develops. Information on egg and zoea amino acids can be used to predict viable crab eggs while information on amino acid profiles in the ovary, egg and zoea can be used to develop broodstock diets. Identification of limiting amino acids in live foods can be used to develop larvae diets.
    • Article

      Amino acid requirements for growth of Nile tilapia 

      CB Santiago & RT Lovell - Journal of Nutrition, 1988 - American Society for Nutrition
      A series of feeding experiments was conducted in aquaria to determine the quantitative requirements of the 10 essential amino acids for growth of young Nile tilapia (Oreochromis niloticus). The test diets contained casein and gelatin supplemented by crystalline L-amino acids to provide an amino acid profile similar to 28% whole egg protein except for the test amino acid. Each set of test diets consisted of seven isonitrogenous diets containing varying levels of the amino acid to be tested. Weight gains analyzed by the broken line regression method indicated the following requirements as a percentage of the dietary protein: lysine, 5.12; arginine, 4.20; histidine, 1.72; valine, 2.80; leucine, 3.39; isoleucine, 3.11; threonine, 3.75; tryptophan, 1.00; methionine with cystine (0.54% of the protein), 3.21; and phenylalanine with tyrosine (1.79% of the protein), 5.54.
    • Article

      Ammonia excretion in Penaeus monodon postlarvae during handling and transfer. 

      JME Almendras - The Israeli Journal of Aquaculture-Bamidgeh, 1994 - Society of Israeli Aquaculture and Marine Biotechnology
      The ammonia excretion rate was used as an index of the physiological state of Penaeus monodon poltlarvae (PL) by monitoring excretion rates after handling and transfer to physiologically different media. The ammonia excretion rate of postlarval P. monodon increased from a mean of 0.543 µg to 0.815 µg total NH3-N per mg dry wt per hour after transfer from 32 to 20 ppt sea water. PL transferred to 40 ppt showed a significant decrease in excretion rate to 0.423 µg total NH3-N per mg dry wt per hour. These changes in excretion rate after transfer to different salinities were only temporary since acclimatized PL showed only minor deviations in excretion rate from the control. PL transferred from normal (8.2) to low (7.2) pH had elevated ammonia excretion rates, from 0.591 µg to 0.733 µg total NH3-N per mg dry wt per hour, while those transferred to high pH (9.2) had excretion rates that dropped drastically to 0.259 µg.

      About 40% of the PL in high pH were moribund after the 150 min exposure. The ammonia excretion rate of PL after a 1 hour feeding was twice that of unfed PL during the first 15 min after transfer. This difference narrowed with time and was no longer significant at 75 min after transfer which also the duration that represented the postprandial surge in ammonia excretion after the 1 hour feeding.
    • Article

      Ammonia excretion rates of the sea bass, Lates calcarifer, in fresh and sea water 

      JME Almendras - The Israeli Journal of Aquaculture-Bamidgeh, 1994 - Society of Israeli Aquaculture and Marine Biotechnology
      The weight-specific ammonia excretion rate of sea bass (Lates calcarifer) fry in fresh water is higher than that of those in sea water. The allometric equation y = 24.426 x -0.4714 best describes the relationship between the ammonia excretion rate (y, in µg total NH3-N/g/hour) and body weight (x, in g wet weight) for fry in fresh water and y = 19.891 x -0.6712 for fry in sea water. The ammonia excretion rate of sea bass fry in fresh or sea water did not significantly increase or decrease during prolonged starvation.

      The pre-feeding ammonia excretion rate of sea bass subadults in fresh water was similar to those in sea water. The ammonia excretion rate of both groups ranged from 3.86 to 4.13 µg total NH3-N per g per hour. Half an hour after feeding, ammonia excretion rates rose to a significant level over pre-feeding values in both freshwater and seawater-adapted subadults. Both groups also showed the same peaks that were 7.5 times higher than pre-feeding levels 3 hours after feeding. By 10 hours after feeding, the ammonia excretion rate of both groups had returned to pre-feeding levels.
    • Article

      Analysing the diel feeding patterns and daily ration of Nile tilapia, Oreochromis niloticus (L.), in Laguna de Bay, Philippines 

      H Richter, U Focken, K Becker, CB Santiago & WB Afuang - Journal of Applied Ichthyology, 1999 - Wiley-Blackwell
      Cage cultured Nile tilapia, Oreochromis niloticus, were sampled at a commercial set-up on two occasions in 1995 in Laguna de Bay, Philippines, each time over a 24 h cycle. The stomach content weights were averaged for each subsample and analysed with the computer model MAXIMS. The model predicted that, in May, larger fish (mean total weight: 31.5 g) feeding on natural food alone fed continuously from dawn to dusk, ingesting 5.1 % body mass equivalent (% BME, wet weight basis) whereas smaller fish (mean total weight: 9.8 g) had two feeding periods per day, from sunrise to mid-morning and again from mid-afternoon until after sunset, ingesting 13.7 % BME. In August, fish were given supplemental feed once daily at 07:00 h. These fish (mean total weight: 81.7 g) fed intensely until supplemental feed ran out before mid-day, after which some ingestion of natural food took place later in the day. The fish ingested 5.8 % BME supplemental feed and 5.1 % BME natural food per 24 h. In May, most of the stomach contents consisted of the blue-green alga Anabaena spiroides, whereas in August, the natural food was made up principally of detritus.
    • Article

      Analysis of nitrite in aqueous solutions containing concentrated matrix ions using an octadecyl-poly(vinyl alcohol) gel microbore column and an electrochemical detector 

      S Rokushika, K Kihara, FM Yamamoto & PF Subosa - Journal of High Resolution Chromatography, 1991 - Dr. Alfred Huethig Publishers
      The importance of the analysis of low level nitrite concentrations in aqueous samples is increasing in various fields such as environmental, food, and aquaculture chemistry. Recent progress in ion chromatography paved the way to the direct analysis of nitrite in water samples at ppm to sub ppb levels. However, analysis of low level nitrite in highly concentrated salt matrix still remains a difficult problem. The presence of a large amount of the matrix ion makes establishment of an ion exchange equilibrium very difficult in the column, often resulting in bad peak shapes [1].

      In previous papers, we reported the analysis of a nitrite and other anions in chloride matrix on a conventional low capacity anion-exchange column by means of a heart-cut and recycling method [1] and by using a potassium chloride eluent [2]. To monitor the nitrite peak, both a UV detector and a conductimetric detector has been used [3]. Several groups have demonstrated the potential of an electrochemical detector for a specific and sensitive detection of nitrate. [4-6].

      Poly(vinyl alcohol) (PVA) gel have been introduced recently as a chemically stable HPLC column packings [7-9]. It was found that when an acidic eluent was employed, a PVA gel and its acylated gel columns produced large capacity factors for nitrite [10].
    • Article

      Anti-luminous Vibrio factors associated with the ‘green water’ grow-out culture of the tiger shrimp Penaeus monodon 

      The ability of the “green water” grow-out culture of the tiger shrimp Penaeus monodon to prevent outbreaks of Luminous Vibriosis was investigated by screening associated isolates of bacteria, fungi, phytoplankton and fish skin mucus for anti-luminous Vibrio metabolites. Among the 85 bacterial isolates tested, 63 (74%) caused +∼+++ inhibition of the Vibrio harveyi pathogen after 24–48 h co-cultivation. The variation in growth inhibition rates of +, ++, and +++ were demonstrated by 15 (18%), 13 (15%), and 28 (33%) isolates, respectively, 24 h after treatment. Eight bacterial isolates showed consistently sustained maximum inhibition of luminous Vibrio after 24 to 48 h exposure. The majority of these luminous Vibrio inhibiting bacterial isolates were obtained from tilapia mucus and gut. In tests with fungi, 4 of 20 (20%) yeast isolates showed intracellular metabolites inhibitory to luminous Vibrio. Among filamentous fungi, 5 of 45 (11%) isolates yielded intracellular metabolites while 3 of 41 (7%) isolates had extracellular metabolites inhibitory to luminous Vibrio. These fungal isolates were identified as Rhodotorula sp., Saccharomyces sp., Candida sp., Penicillium sp., mycelia sterilia, and two unidentified species. The microalgae, Chaetoceros calcitrans and Nitzchia sp., consistently demonstrated complete inhibition of luminous Vibrio from 24 h and 48 h post exposure, respectively, and during the 7-day experiment. Leptolyngbia sp. caused a 94–100% reduction of the luminous Vibrio population from 104 to 101 cfu/ml 24 h post exposure which was sustained throughout the 10-day observation period. In contrast, the inhibitory effects of Skeletonema costatum on luminous Vibrio was bacteriostatic throughout the 7-day exposure while Nannochlorum sp. did not significantly inhibit luminous Vibrio. The skin mucus of jewel tilapia, Tilapia hornorum, had no resident luminous bacteria and inhibited this bacterial pathogen in 6–48 h, which was proportionate to the 103 and 105 cfu/ml test concentrations of luminous Vibrio. This study provides a scientific explanation that the effectiveness of the “green water” culture of tiger shrimp (P. monodon) in preventing outbreaks of luminous Vibriosis among P. monodon juveniles in grow-out ponds can be attributed to the presence of anti-luminous Vibrio factors in the bacterial, fungal, phytoplankton microbiota and the skin mucus of tilapia associated with this novel technique of shrimp culture.
    • Article

      Antibacterial activity of tilapia Tilapia hornorum against Vibrio harveyi 

      EA Tendencia, MR dela Peña, AC Fermin, G Lio-Po, CH Choresca Jr. & Y Inui - Aquaculture, 2004 - Elsevier
      Disease due to luminous Vibrio has been a major problem of the shrimp industry. Different technologies have been introduced to control the disease. One of the techniques reported to work against luminous bacteria in the Philippines is the green water culture system (or finfish–shrimp integrated culture system). A green water culture system is an innovative technique wherein shrimp are cultured in water collected from a pond where tilapia or other fish species are grown. In some cases, the fish are cultured in an isolated net pen inside the shrimp culture pond. This study clarifies the effect of one component of the green water culture system, the presence of all male tilapia (Tilapia hornorum) on luminous bacteria Vibrio harveyi. Results showed that stocking tilapia at a biomass not lower than 300 g/m3 efficiently inhibited the growth of luminous bacteria in shrimp (biomass=80 g/m3) rearing water without the growth of microalgae.
    • Article

      Antibacterial properties of the microalgae Chaetoceros calcitrans 

      EB Seraspe, BF Ticar, MJ Formacion, IG Pahila, MR de la Peña & EC Amar - Asian Fisheries Science, 2012 - Asian Fisheries Society
      The antibacterial properties of the microalgae Chaetoceros calcitrans were assessed. Samples of C. calcitrans were first extracted in methanol, and then in different organic solvents of increasing polarity, n-hexane (n-Hex), dichloromethane (DCM) and ethyl acetate (EA) by liquid-liquid extraction. Solvent extracts were screened for antibacterial activity against four species of bacteria: Gram positive, Staphylococcus aureus and Bacillus subtilis; and Gram negative, Escherichia coli and Vibrio harveyi, with Amoxicillin as positive control, N-Hex extract, with significantly lower antibacterial activity than Amoxicillin, showed significantly higher activity than DCM and EA extracts, and least in methanolic extract. High antibacterial activity of n-Hex extract against all the microorganisms indicates that the bioactive components could be non-polar since the activity decreased as the solvent became more polar like methanol, and finally lost in aqueous extract. Results also showed that the extracts have a broad spectrum activity. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of all solvent extracts on all microorganisms tested ranged from 125 to 500 μg.mL-1. Partial purification and characterisation of the extracts confirmed the antibacterial activity in the non-polar fraction, which could be terpenes. The results suggest a good prospect in using C. calcitrans against Vibrio and other bacterial species.
    • Article

      Antibiotic resistance of bacteria from shrimp ponds 

      EA Tendencia & LD de la Peña - Aquaculture, 2001 - Elsevier
      The incidence of antibiotic resistance was compared in bacteria isolated from pond water, pond sediment, water and sediment from the receiving environment (area where water from pond drains, which is 0 and 50 m away from the exit gate, in this study) and cultured shrimp from ponds that have not used any antimicrobials, ponds that have previously used antimicrobials and ponds that are currently using oxolinic acid. Most of the bacteria isolated from all sample and pond type were Vibrios. Among the Vibrios, V. harveyi were most commonly isolated. Multiple antibiotic resistance (MAR) to at least two antimicrobials was highest in ponds currently using oxolinic acid (24% of bacteria isolated from such ponds), followed by those that have previously used antimicrobials (19%) and the least was those from ponds that have not used any antimicrobials (17%). The lowest incidence of antibiotic resistance was observed in ponds that have not used any antimicrobials (41% of the isolates from such ponds). Among the individual antibiotics, incidence of resistance to oxytetracycline was highest (4.3% of the total number of isolates) followed by furazolidone (1.6%), oxolinic acid (1%) and chloramphenicol (0.66%).

      Resistance to individual chemotherapeutants did not reflect the pattern of antimicrobial use with ponds that have previously used antimicrobials showing the highest incidence of resistance to one antimicrobial (12% of total isolates from such ponds). Resistance to both oxolinic acid and furazolidone (15% of total number of isolates) was highest compared to other antimicrobial resistance profiles (1–12%). Multiple antimicrobial resistance and intermediate reaction to at least one antimicrobial are associated with antimicrobial use.
    • Article

      Antimicrobial activity screening of Lyngbya majuscula crude methanolic extract against selected aquaculture pathogens 

      LG Ayukil III, EB Seraspe, DEG Corda, IG Pahila & MR de la Peña - Philippine Journal of Natural Sciences, 2010 - University of the Philippines Visayas
      Lyngbya majuscula crude methanolic extract (LMCME) was screened for antimicrobial properties in vitro. The Gram-negative Vibrio harveyi and Aeromonas hydrophila and the Gram-positive Staphylococcus aureus and Micrococcus luteus were used as reference test bacteria. The filamentous Lagenidium sp. was used as test fungus. LMCME showed a poor or weak antibacterial activity against the bacterial isolates. The activity against V. harveyi was observed at 1,000 mg/mL-1 while that against A. hydrophila was at 500 and 1,000 mg/mL-1 concentrations. These activities, however, were significantly lower (p<0.05) than the positive control (chloramphenicol). The activity of LMCME against S. aureus and M. luteus was observed in all the test concentrations, but it was against the M. luteus that the extract had high antibacterial activity. This activity, however, was significantly lower (p<0.05) than chloramphenicol. The antifungal activity test exhibited 100% mycelial growth inhibition at 100 mg/mL-1 concentration and was comparable (p>0.05) with the positive control (malachite green). The minimum inhibitory concentration (MIC) of LMCME against Lagenidium sp. was at 50 mg/mL-1, and the minimum fungicidal (lethal) concentration (MFC) at 100 mg/mL-1. Phytochemical screening revealed the presence of alkaloids to which its antifungal activity may be attributed. Brine shrimp assay against the larvae of Artemia salina L each showed that the LMCME was not toxic even at the highest concentration (1,000 mg/mL-1). By and large, L. majuscula can be a potential source of secondary metabolites that can be used for the control and treatment of larval mycosis in the aquaculture industry.
    • Article

      Antimicrobial susceptibility of Aeromonas spp., Vibrio spp. and Plesiomonas shigelloides isolated in the Philippines and Thailand 

      RP Maluping, CR Lavilla-Pitogo, A DePaola, JM Janda, K Krovacek & C Greko - International Journal of Antimicrobial Agents, 2005 - International Society of Chemotherapy
      Aeromonas spp., non-cholera vibrios (NCVs) and Plesiomonas shigelloides belong to the expanding group of water and food-borne pathogens. They are widely distributed in aquatic environments and are increasingly regarded as important pathogens of aquatic animals, causing significant economic losses in the aquaculture industry worldwide. In addition, these bacteria have been implicated as opportunistic pathogens, mainly causing gastroenteritis in humans. The occurrence and isolation of these bacteria from different sources has been reported in Asia, including the Philippines and Thailand. However, information on antimicrobial susceptibility of these isolates, especially those recovered from aquaculture and aquatic environments is scarce. The aim of this study was to acquire data on the occurrence of antimicrobial resistance among 38 strains of Aeromonas spp., NCVs and P. shigelloides isolated from different sources in the Philippines and Thailand. In addition, the production of extended-spectrum ß-lactamases (ESBLs) by selected strains was determined.
    • Article

      Apparent digestibility coefficient of nutrients from shrimp, mussel, diatom and seaweed by juvenile Holothuria scabra Jaeger 

      ZGA Orozco, JG Sumbing, MJH Lebata-Ramos & S Watanabe - Aquaculture Research, 2014 - Wiley
      The ability of Holothuria scabra to digest nutrients, such as organic matter (OM), protein and carbohydrate from animal and plant feed ingredients was investigated. Four test feeds prepared by mixing sand with single ingredients from animal sources (shrimp and mussel) and plant sources (diatom and seaweed) were fed to H. scabra to estimate apparent digestibility coefficient (ADC). The total assimilated nutrient (TAN) increased with ADC, whereas ingestion rate (IR) varied slightly among the feeds suggesting that ADC might be a good indicator of nutrient availability to H. scabra. The ADCOM of shrimp and mussel was significantly higher than that diatom and seaweed: 86.2%, 77.1%, 55.1% and 32.3% respectively. ADCprotein was similar for shrimp (88.7%), mussel (84.8%) and diatom (75.2%), but significantly lower in seaweed (34.4%). ADCcarbohydrate was similar in mussel (58.5%) and diatom (58.3%) as well as in seaweed (31.6) and shrimp (28.0%). ADCprotein was relatively higher than ADCcarbohydrate suggesting that H. scabra generally digests more protein than carbohydrate. Furthermore, results indicated that nutrients from animal-based feeds are more efficiently digested by H. scabra; thus, animal ingredients rich in easily digestible protein could potentially provide an efficiently balanced diet for H. scabra fed with diatom containing high easily digestible carbohydrate.
    • Article

      Apparent digestibility of diets with various carbohydrate levels and the growth response of Penaeus monodon 

      MR Catacutan - Aquaculture, 1991 - Elsevier
      The digestibility of four isonitrogenous practical diets (40% crude protein) containing different levels (5%, 15%, 25% and 35%) of gelatinized breadflour as carbohydrate source were determined for P. monodon (average weight 30–40 g). The digestibility coefficients for protein ranged from 92.8 to 94.3%. Crude fat digestibility ranged from 90.0 to 92.8% and dry matter digestibility from 75.7 to 86.9%. Carcass crude protein was similar in all treatments but carcass crude fat decreased significantly (P<0.05) with increasing dietary carbohydrate.

      The same diets were fed to a group of smaller P. monodon (average initial weight=0.139±0.011 g) for 8 weeks. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR) and survival rate did not differ significantly (P>0.05) among treatments. However, weight gain and SGR were lowest and FCR was poorest with 35% carbohydrate.
    • Article

      Apparent digestibility of selected feedstuffs by mud crab, Scylla serrata 

      MR Catacutan, PS Eusebio & Si Teshima - Aquaculture, 2003 - Elsevier
      A feeding experiment was conducted to determine apparent digestibility coefficients for dry matter (ADMD), crude protein (ACPD), crude fat (ACFD), crude fiber (ACFbD), nitrogen-free extract or NFE (ANFED), and crude ash (AAD) of selected feed ingredients for mud crab, Scylla serrata. The nine feed ingredients were Peruvian fish meal, squid meal, Acetes sp., meat and bone meal, copra meal, wheat flour, rice bran, corn meal, and defatted soybean meal. A reference diet (RF) and test diets (consisted of 70% RF diet and 30% of the feedstuff) were used with Cr2O3 as external indicator.

      The ADMD of the RF and test diets were high except for diet with meat and bone meal. Crude protein, crude fiber, and ash of feedstuffs were digestible in mud crab. Nutrients in squid meal, corn meal, and defatted soybean meal were digested well (ACFbD>95%; ANFED>92%; AAD>71%) compared with nutrients in the meat and bone meal. The AAD of copra meal, wheat flour, rice bran, and meat and bone meal were similar. The ACFD in carbohydrate-rich plant feedstuffs were significantly higher than that in protein-rich animal feedstuffs. For this species, the relative amounts of dietary protein and NFE in feedstuffs had an effect on the ACFD but not on ADMD.
    • 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

      Application of poly-β-hydroxybutyrate (PHB)-based biodegradable plastic as artificial substratum in Litopenaeus vannamei culture 

      G Ludevese-Pascual, JL Laranja, E Amar, P Bossier & P De Schryver - Journal of Polymers and the Environment, 2019 - Springer
      The use of artificial substratum made out of poly-β-hydroxybutyrate (PHB) based biodegradable plastic for penaeid shrimp culture was investigated for the first time. Provision of PHB substratum consisting of PHB type P209 (Biomer, Krailling, Germany) to postlarval whiteleg shrimp Litopenaeus vannamei (106 ± 52 mg) resulted in significantly higher survival (P ≤ 0.05) of 83.6 ± 3.4% as compared to 73.9 ± 3.0% for postlarvae provided with conventional substratum consisting of polyvinylchloride (PVC) pipes. Results on final weight showed significantly higher weight (P ≤ 0.05) of 1008.2 ± 4.5 mg in postlarval whiteleg shrimp provided PHB substratum as compared to 893.4 ± 30.0 mg for postlarvae provided with PVC substratum. The trends of higher visit and preference by postlarval whiteleg shrimp on 10-day and 70-day aged PHB substrata over 10-day and 70-day aged PVC substrata suggest the importance of PHB substratum as grazing area rather than as shelter. Test conducted on water quality also showed a trend towards higher total ammonia-nitrogen (TAN) conversion from an initial concentration of 1.75 ± 0.0 mg L−1 to 0.35 mg ± 0.04 mg L−1 after 72 h with PHB substratum while using no substratum and PVC substratum lead to TAN concentrations of 1.28 ± 0.06 mg L−1 and 1.23 ± 0.10 mg L−1, respectively. Overall, this study indicates that artificial substratum consisting of PHB-based biodegradable plastic increases the quality of postlarval whiteleg shrimp and that it contributes to maintaining good water quality.