Now showing items 1-20 of 53

    • Book chapter

      Amino and fatty acid profiles of wild-sourced grouper (Epinephelus coioides) broodstock and larvae 

      VR Alava, FMP Priolo, JD Toledo, JC Rodriguez Jr., GF Quinitio, AC Sa-an, MR de la Peña & RD Caturao - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      This study was undertaken to provide information on the levels of amino acids in the muscle, liver and gonad of wild-sourced broodstock and larvae, as well as in neurula eggs and day 35 larvae from a hatchery. The fatty acid composition of grouper broodstock tissues was also determined. Samples were analysed for crude protein, amino acids, total lipids and fatty acid contents. Muscle contained higher levels of crude protein and amino acids than the ovary and liver. At the early maturing stage, the grouper ovarian protein was 73.3% and lipid was 19.3%, indicating the high dietary requirements of these nutrients for ovarian development. The crude protein and amino acid contents in wild-sourced larvae were higher than that in eggs and larvae from the hatchery.
    • Book

      Bangus fry resource assessment in the Philippines 

      M Ahmed, GA Magnayon-Umali, RA Valmonte-Santos, J Toledo, N Lopez & F Torres Jr. - 2001 - ICLARM - The World Fish Center
      Series: ICLARM Technical Report; 58
      Bangus or milkfish is the national fish of Philippine. Bangus culture is traditionally based on fry collected from the wild. Due to growing demand for fry the bangus industry. The Philippines Bureau of Fisheries and Aquatic Resources (BFAR), the Philippine Council of Aquatic and Marine Research and Development (PCAMRD), the Southeast Asian Fisheries Development Centre (SEFDEC) and ICLARM embarked of the conditions prevailing in the milkfish fry sector, project workshop was held in 1999. The present report is the outcome of workshop. Report highlights on the issues milkfish production, fry production in hatcheries, fry gathering activities, marketing issues, management of fry gathering grounds and its marketing and the related policy issues.
    • Book chapter

      Changes in the gastrointestinal tract and associated organs during early development of the grouper (Epinephelus coioides) 

      GF Quinitio, AC Sa-an, JD Toledo & JD Tan-Fermin - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      The histomorphological changes in the gastrointestinal tract of Epinephelus coioides and associated organs during its early development were studied. Larvae of E. coioides were reared in 5-tonne tanks using the semi-intensive culture system. Larval samples were collected at days 0, 2, 4, 6, 8, 10, 12, 14, 16, 20, 25, 30, 35, 40, 45 and 60. The total length (TL) of about 10-20 larvae per sampling was measured. At least 3 samples were examined from each stage for longitudinal sections using light microscopy. The digestive tract of day 0 larvae was a straight, undifferentiated tube composed of simple cuboidal cells. At day 2, cellular differentiation was observed in the pharynx, oesophagus, primordial stomach and intestine. The primordial stomach broadened into a voluminous pouch at day 10. The gastric gland was observed in the stomach from day 20. Day 35 seemed to be the proper time to feed larvae with minced fish when using the semi-intensive rearing system. Insignificant histomorphological changes in the metamorphosing grouper larvae were observed from days 40-60.
    • Article

      Characterization of betanodaviruses in the Philippines 

      LD de la Peña, K Mori, GF Quinitio, DS Chavez, JD Toledo, VS Suarnaba, Y Maeno, I Kiryu & T Nakai - Bulletin of the European Association of Fish Pathologists, 2008 - European Association of Fish Pathologists
      Viral nervous necrosis caused by betanodaviruses is one of the most devastating diseases in cultured marine finfish. In the Philippines, mass mortalities occurred in sea bass, Lates calcarifer larvae and grouper, Epinephelus coioides broodstock. The virus was isolated using SSN-1 fish cell line and confirmed by PCR. Cytopathic effect started to develop in the cell line 2 days post infection (p.i) with tissue filtrates until the cells completely disintegrated and detached from the flask at 5 days p.i. and the viral protein was detected by immunofluorescence. Sequence analysis revealed that VNN isolated from the brain of grouper broodstock and sea bass larvae were 98.6% similar. Sequence analysis between the Philippine isolates and red-spotted grouper nervous necrosis virus (RGNNV) genotype is 96.9% similar as compared to 72.0% and 64.0% similar with the barfin flounder nervous necrosis virus (BFNNV) and tiger puffer nervous necrosis virus (TPNNV) genotypes, respectively. These results confirm that the Philippine isolates belong to RGNNV genotype.
    • Conference paper

      Collection of naturally-spawned milkfish eggs in floating cages 

      CL Marte, J Toledo, G Quinitio & A Castillo - In JL Maclean, LB Dizon & LV Hosillos (Eds.), The First Asian Fisheries Forum. Proceedings of the First Asian Fisheries Forum, 26-31 May 1986, Manila, Philippines, 1986 - Asian Fisheries Society
      Natural spawnings of milkfish from floating cages were obtained from different stocks of 5-7 year-old milkfish in 1980, 1981, 1983 and 1985. The maximum number of eggs collected in 1980, using a series of 1-m diameter stationary plankton nets, was about 900. Increased collections were obtained in succeeding years with different types of egg collectors and methods. Egg collection, however, is inferior when based on the expected number of eggs spawned by a single female. Although no systematic study was attempted to compare efficiency of various egg-collecting gears and methods, the problems associated with the use of each gear are presented. The experience may be used as a guide in future designs of efficient gears of collecting naturally-spawned eggs of milkfish or other fish species in floating cages.
    • Article

      Comparison of fatty acid profile between cultured and wild-caught grouper Epinephelus coioides 

      JD Toledo, ES Ganzon-Naret & H Nakagawa - Suisan Zoshoku, 2005 - Japan Aquaculture Society
      The lipid content and fatty acid composition were examined in the liver, eye, muscle, brain and intraperitoneal fat body (IPF) of hatchery-bred and wild-caught orange-spotted grouper, Epinephelus coioides. The cultured and wild grouper were classified into three different body weights (small, medium and large size), and submitted to lipid content and fatty acid analysis. Muscle lipid in cultured grouper increased lineally with growth, but that of wild fish decreased. The amount of lipid in the IPF in cultured fish was higher than wild fish. Lipid content and essential fatty acids in cultured fish showed significant change with growth. All organs in the early growth stage of cultured fish seemed to contain poor arachidonic acid (AA) than the wild fish. The liver of small sized cultured fish contained low AA and docosahexaenoic acid (DHA), but no profound change was found in AA during growth of fish. While the proportion of DHA in the liver and IPF increased with growth in cultured fish, muscle DHA decreased with growth. The difference in fatty acid composition between cultured and wild fish disappeared with growth.
    • Article

      Critical factors influencing survival and hatching of milkfish (Chanos chanos Forsskal) eggs during simulated transport 

      LMB Garcia & JD Toledo - Aquaculture, 1988 - Elsevier
      The effects of loading density, length of transit time, temperature and salinity on milkfish (Chanos chanos Forsskal) eggs during simulated transport were examined. Rocking motion approximating conditions of transport of eggs collected from milkfish broodstock floating net cages to a hatchery was simulated using a laboratory orbit shaker. Loading densities of more than 7000 eggs/l in shipping bags resulted in decreased rates of survival and correspondingly lower hatching rates. Prolonged shaking simulating extended periods of egg transport also resulted in low egg survival and hatching rates compared to fertilized eggs not subjected to simulated transport. Egg survival after simulated transport at 20°C was lower than at 28°C, except at 20 ppt salinity, where survival was equal. Egg survival at 20°C progressively increased with declining salinity levels whereas high egg survival rates were observed after 2 h of simulated egg transport at 28°C and at the three salinities tested. Hatching rates of fertilized eggs after simulated transport were higher at 28°C than at 20°C regardless of salinity. Neither salinity nor its interaction with temperature affected hatching rates of eggs after simulated transport. These results indicate that survival and hatching of fertilized milkfish eggs after simulated transport is influenced by loading density, transport time, temperature and, to some degree, the salinity of the water. Based on these results, guidelines for handling and transporting milkfish eggs are given.
    • Article

      Cryopreservation of different strains of the euryhaline rotifer Brachionus plicatilis embryos 

      JD Toledo, H Kurokura & H Nakagawa - Nippon Suisan Gakkaishi, 1991 - Japanese Society of Fisheries Science
      Cryopreserevation of different strains of Brachionus plicatilis symmetrical stage embryos was conducted. One S-type strain, namely Yashima-S (YS), and three L-type strains, namely Yashima-L (YL), Nagasaki (NG), and Hamana (HA), were used. Symmetrical stage embryos in 10% DMSO-28‰ sea water solution were frozen at -196°C using a two-step freezing procedure; the embryos were first cooled slowly from -5°C to -20°C at a rate of 0.3°C/min and then cooled rapidly by direct transfer to liquid nitrogen. Frozen samples were thawed in a gently stirred water bath at room temperature.

      A mean survival rate of 36% after 30 days storage in liquid nitrogen of HA strain was significantly lower than YS (55%), YL (58%), and NG (54%), and is due likely to its relatively larger embryo volume. There was no significant difference in the intrinsic rate of increase (r) between strains among clones taken from the cryopreservation or unfrozen control group. The results also indicate that various strains of B. plicatilis embryos can be cryopreserve without seriously altering their reproductive capability. The freezing method described could be of great potential in aquaculture and in future studies on rotifer genetics.
    • Article

      Cryopreservation of the euryhaline rotifer Brachionus plicatilis embryos 

      JD Toledo & H Kurokura - Aquaculture, 1990 - Elsevier
      A method for the separation and cryopreservation of Brachionus plicatilis embryos is described. Juveniles with uniform development were collected from a cultured stock by passing them through a series of nets. Collected juveniles were cultured and the embryos separated by vigorous vortex mixing as soon as the majority had laid their first eggs. Separated embryos at stage I (cleavage stage), stage II (invagination stage), stage III (symmetrical embryo stage), or stage IV (“eyed” stage) were frozen to −196°C using various concentrations of DMSO and a two-step freezing procedure. No stage I embryos survived freezing and the highest post-thaw survival was obtained with stage III embryos. A DMSO concentration of 10% of the freezing medium resulted in high post-thaw survival while concentrations higher than 10% appeared to be harmful to embryos. Prolonged incubation in 10% DMSO for up to 30 min before freezing increased post-thaw survival.

      Incorporating the above results, stage III embryos from a single batch culture were incubated in 10% DMSO for 30 min and frozen to −196°C. Post-thaw survival rates of 63%, 62%, 53%, and 55% were obtained after 3, 7, 15, and 30 days of storage in liquid nitrogen, respectively. Survivors fed actively on marine chlorella and started to lay eggs 2–3 days after thawing.
    • Conference paper

      Culture of grouper, sea bass and red snapper 

      JD Toledo - In Fishlink 2001, 29-31 May 2001, Sarabia Manor Hotel, Iloilo City, 2001 - University of the Philippines Aquaculture Society, Inc.
      Marine fish production has increased dramatically in the past ten years and majority of the cultured species were produced in Asia in 1992. Increase in production was accompanied with concerns on increasing outbreak of disease, degradation of environment as a consequence of culture practices, and the alleged shortage of seed supply and feeds. This paper reviews the state of the art of the culture of grouper, sea bass and red snapper.
    • Article

      Density dependent growth of the tropical abalone Haliotis asinina in cage culture 

      EC Capinpin Jr., JD Toledo, VC Encena II & M Doi - Aquaculture, 1999 - Elsevier
      The effects of different stocking densities on the growth, feed conversion ratio and survival of two size groups of the tropical abalone Haliotis asinina were determined. Three culture trials were conducted in net cages installed in a sheltered cove, Guimaras Province, Philippines. Trials 1 and 2 were conducted using 15–20 mm abalone juveniles for 150 days, while trial 3 was conducted using 35–40 mm abalone for 180 days. The animals were fed sufficient amounts of the red alga, Gracilariopsis bailinae (=G. heteroclada), throughout the experiment. There was an inverse relationship between growth (length and weight) and stocking density. Feed conversion ratio was not influenced by density, but was observed to be higher for larger animals. Survival was not significantly affected by density. Net cages are appropriate for culture of H. asinina. This study showed that H. asinina can reach commercial size of about 60 mm in one year. It also showed that growth of H. asinina can be sustained on a single-species diet. An economic analysis will be important in choosing the best stocking density for commercial production.
    • 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.
    • Book chapter

      Digestive enzyme activity in developing grouper (Epinephelus coioides) larvae 

      PS Eusebio, JD Toledo, REP Mamauag & MJG Bernas - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      This study was undertaken to determine the activities of alkaline and acid type proteases [proteinases], α-amylase, lipase [triacylglycerol lipase], trypsin, chymotrypsin, leucine aminopeptidase [cytosol aminopeptidase], and alkaline and acid phosphatases during larval development of the grouper, Epinephelus coioides. The maximum variation in specific activities of alkaline and acid type proteases, α-amylase, lipase, trypsin, chymotrypsin, leucine aminopeptidase, and acid and alkaline phosphatases in the digestive tract of grouper larvae was mostly related to the onset or the end of metamorphosis during larval development.
    • Article

      Effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, growth and survival of early-stage grouper Epinephelus coioides larvae 

      JD Toledo, NB Caberoy, GF Quinitio, CH Choresca & H Nakagawa - Fisheries Science, 2002 - Springer Verlag
      A series of experiments were conducted to examine the effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage Epinephelus coioides larvae. Newly hatched larvae were transferred to 40-L aquaria at a density of 1500 individuals/aquarium. Larvae were exposed to different levels of aeration (0 mL/min per L, 0.62 mL/min per L, 1.25 mL/min per L, 2.50 mL/min per L, or 3.75 mL/min per L); salinity (8 ppt, 16 ppt, 24 ppt, 32 ppt, or 40 ppt); and light intensity (0 lx, 120 lx, 230 lx, 500 lx, or 700 lx) for 4–6 days. Twenty larvae were sampled daily at 11:00 hours to measure for total length (TL), oil globule volume, and feeding incidence. Survival rates were determined by counting the total number of larvae remaining in each aquarium at the end of the experiment. Significantly higher survival rates (P < 0.05) were observed at aeration levels of 0.62 mL/min per L and 1.25 mL/min per L, at salinity levels of 16 ppt and 24 ppt, and at light intensities of 500 lx and 700 lx. The influence of aeration level, salinity and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage grouper larvae are discussed.
    • Article

      Egg cannibalism by milkfish (Chanos chanos Forsskal) spawners in circular floating net cages 

      JD Toledo & AG Gaitan - Journal of Applied Ichthyology, 1992 - Blackwell Publishing
      Egg cannibalism by milkfish spawners in a circular floating net cage was investigated. The cage was lined with a fine mesh hapa net to retain spawned eggs and to prevent the entry of fish egg predators. Water samples were collected from the surface (0 m), middle (1.5 m), and bottom (3.0 m) of a 10 m diameter by 3 m deep floating net cage at the time of initial detection of spawning (0 min) and at 30, 60, 120 and 240 min thereafter. The mean number of spawned eggs at the surface significantly decreased (P<0.05) 60 min after spawning and very few eggs were recovered 240 min later. There was no significant difference (P>0.05) in the mean number of spawned eggs collected from the middle and bottom of the net cage at various times after spawning. Eggs were found in the digestive tract of all milkfish sampled (n=6) at about 5 h after spawning, indicating that captive milkfish eat their own eggs. It is recommended that spontaneously spawned milkfish eggs should be collected immediately after spawning to avoid loss by egg cannibalism.
    • Conference paper

      Egg quality of grouper Epinephelus coioides fed different fatty acid sources 

      GF Quinitio, RM Coloso, NB Caberoy, JD Toledo & DM Reyes Jr. - In D MacKinlay & M Eldridge (Eds.), The Fish Egg: Its Biology and Culture Symposium Proceedings. International Congress on the Biology of Fishes, 14-18 July 1996, San Francisco State University, 1996 - American Fisheries Society, Physiology Section
      Quality of eggs spawned by Epinephelus coioides fed fish by catch (control). Cod liver oil-enriched fish by catch (TFC), and commercial HUFA A-enriched fish by catch (TFS) was monitored. Monthly egg production, spawning frequency, fertilization rate, egg viability, and hatching rates of the control were significantly higher compared to TFS Egg production. Spawning frequency and hatching rate of TC and TFS were not significantly different. Results suggest that varying the species of fish by catch could provide the requirements of E. Coioides broodstock so as to provide quality eggs.
    • Book chapter

      Environmental factors affecting embryonic development, hatching and survival of early stage larvae of the grouper (Epinephelus coioides) 

      JD Toledo, NB Caberoy & GF Quinitio - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
      Series: ACIAR Monograph 110
      These series of experiments were conducted to determine the effects of density (200, 400, 800 and 1600 eggs/litre), salinity (8, 16, 24, 32 and 40 ppt), aeration (0, 0.62, 1.25, 2.50 and 3.75 ml/min/litre) and light intensity (0, 120, 230, 500 and 700 lx) on the survival of fertilized eggs and early stage larvae of Epinephelus coioides. Under statice incubation conditions, the highest egg viability, hatching rate and percentage of normal larvae were obtained at a stocking density of 400 eggs/litre with moderate aeration (100 ml/min) and salinity of 32-42 ppt. Gentle aeration at 0.62 to 1.25 ml/min/litre, rearing water of 16 to 24 ppt and a light intensity of 500 to 700 lx maximized the survival of early stage E. coioides larvae in the hatchery.
    • Article

      The financial feasibility of small-scale grouper aquaculture in the Philippines 

      RS Pomeroy, R Agbayani, MN Duray, J Toledo & G Quinitio - Aquaculture Economics and Management, 2004 - International Association of Aquaculture Economics and Management (IAAEM)
      This paper presents the results of an economic analysis of the aquaculture of two species of grouper E. coloides (orange‐spotted grouper, green grouper, red‐spotted grouper) and E. malabaricus (malabar grouper, black‐spotted grouper) for small producers in the Philippines. The findings of the analysis indicate that, based on the assumptions, grouper culture is financially feasible. However, the capital requirements for the broodstock, hatchery/nursery, and integrated system may be beyond the financial means of many small producers. These stages of grouper culture may need to be developed as a larger project by private investors or government. The capital investment requirement for grow‐out (not including purchase of transport boxes) is within the financial means of small producers. Loans or other incentives will need to be made available for the small producer, but the cash flow indicates that these loans can be repaid in the first year of production.
    • Article

      Food selection of early grouper, Epinephelus coioides, larvae reared by the semi-intensive method 

      JD Toledo, SN Golez, M Doi & A Ohno - Suisan Zoshoku, 1997 - Japan Aquaculture Society
      The grouper, Epinephelus coioides, larvae were reared in outdoor tanks with nauplii of copepods and/or rotifers, Brachionus rotundiformis as food. Nauplii propagated in tanks consisted mainly of Pseudodiaptomus annandalei and Acartia tsuensis. Gut content was examined for a total of 953 larvae sampled from day 3 to day 10 (day of hatching being day 0) . Grouper larvae successfully started feeding on early stage nauplii even if their abundance was as low as ca. 100 ind./l and showed better survival and growth thereafter compared to those fed with rotifers only. Feeding incidence reached 100% on day 4 when nauplii were available and only on day 9 when rotifers were given alone. Selective feeding ability of larvae seemed to start from day 4 and the larvae thereafter preferred to feed on medium- and large-size nauplii than rotifers. Coastal calanoid copepods of the genera Pseudodiaptomus and Acartia could be reproduced in tanks and their nauplii can be used as food for marine fish larval rearing.
    • Book chapter

      Grouper aquaculture R&D in the Philippines 

      JD Toledo - In IC Liao & EM Leaño (Eds.), The Aquaculture of Groupers, 2008 - Asian Fisheries Society; World Aquaculture Society; The Fisheries Society of Taiwan; National Taiwan Ocean University
      Culture of groupers in ponds and floating net cages has been practiced for many years in the Philippines. Unsustainable culture practices such as dependence on wild caught seeds, use of trash fish, use of high stocking densities, and unregulated expansion and proliferation of fish cages, have led to the "boom and bust" cycle of grouper aquaculture in the Philippines. The drastic decrease in grouper aquaculture production in the late 90's was mainly attributed to environmental deterioration and diseases outbreaks. To sustain grouper production, research on the breeding, seed production and culture of groupers started in the mid 1980s. As a regional inter-government R&D organization, the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD) followed the recommendations of the 1987 Seminar-Workshop on Aquaculture Development in Southeast Asia on grouper R&D. Research activities initially focused on market survey of grouper species in the Philippines and Southeast Asia, assessment of fry and availability in traditional fishing grounds, and development of broodstock management techniques. Following the spontaneous spawning of Epinephelus coioides in concrete tanks and floating net cages in 1990's, protocols for the seed production of milkfish and sea bass were adapted and modified. Parallel studies to determine sustainable culture techniques in ponds and net cages were conducted. Studies on the nutritional requirements of grouper at various developmental stages were done to reduce dependence on live prey organisms and trash fish as feeds. Research geared towards health management started in the in late 90's to early 2000's. Prospects for grouper aquaculture are discussed in the light of recent advances in grouper R&D and the Government of the Philippines initiatives to increase fish production by mariculture.