Now showing items 1-17 of 17

    • Conference paper

      Acceptability of five species of freshwater algae to tilapia (Oreochromis niloticus) fry 

      JB Pantastico, JP Baldia & D Reyes Jr. - In CY Cho, CB Cowey & T Watanabe (Eds.), Finfish Nutrition in Asia : Methodological Approaches to Research and Development, 1985 - International Development Research Centre
      Unialgal cultures of Oscillatoria quadripunctulata, Chroococcus dispersus, Navicula notha, Euglena elongata, and Chlorella ellipsoidea were fed to tilapia fry for 30 days. Mean weights and survival rates of the fry were highest when given Navicula (105.6 mg, 86%) and Chroococcus (89.1 mg, 90%). Oscillatoria, a filamentous cyanophyte, showed limited acceptability to tilapia fry, possibly because of its larger size in comparison with Chroococcus. Fry fed Chlorella and Euglena did not survive at all.

      C14-labeled algae of the above species were fed to tilapia fry of varying ages. Assimilation rates per fry after 24 hours of feeding with a suitable algal species increased with the age of the fry. Moreover, the same trend as in the growth and survival experiments was observed, i.e., the highest assimilation rates were obtained in 40-day old tilapia fry given Navicula and Chroococcus as natural feeds. On the other hand, negligible amounts of the other three algal species tested were assimilated by tilapia fry.

      The above results were explained in terms of the enzyme secretion of tilapias. There seemed to be no transition stage in the feeding habit of both fry and adult tilapia. The acceptability of plant matter in the diet of even the early larval stages was demonstrated.
    • Conference paper

      Algal production and utilization relevant to aquaculture in the Philippines 

      JB Pantastico, JP Baldia, CC Espegadera & DM Reyes Jr. - In IJ Dogma Jr., GC Trono Jr. & RA Tabbada (Eds.), Culture and use of algae in Southeast Asia. Proceedings of the Symposium on Culture and Utilization of Algae in Southeast Asia, 8-11 December 1981, Tigbauan, Iloilo, Philippines, 1990 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An outline is given of research conducted at the Aquaculture Department of SEAFDEC at Rizal, Philippines regarding algal culture and utilization. Culture methods for both brackishwater and freshwater algae are described and details given of applications of microalgae in the aquaculture industry, which include feed for fish and shrimp larvae.
    • Conference paper

      Effects of different fat sources on the egg quality of grouper, Epinephelus suillus 

      GF Quinitio, RM Coloso, A Duller & D Reyes - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The effect of different fat sources on the egg quality of grouper, Epinephelus suillus eggs was evaluated. Fish in three tanks, each containing 3 females and 1 male, were fed various types of feeds namely: trash fish (control), trash fish + cod liver oil (treatment 1) and trash fish + SELCO, a lipid emulsion containing high levels of highly unsaturated fatty acid (HUFA) (treatment 2).

      Approximately 77.9 million eggs spawned from January to October 1992 by the control group, 40.0 million by fish in treatment 1, and 36.4 million by the treatment 2 group. Egg production (0.45 million eggs/kg BW) among the control group was significantly higher than treatment 2. Egg production of treatment 1 (0.06-0.36 million eggs/kg BW) was not significantly different (P<0.01) from the control group nor treatment 2 (0.02-0.30 million eggs/kg BW). Fertilization and hatching rates showed significant differences among the three groups with control > treatment 1 > treatment 2. There were no differences detected in the egg and oil globule diameters among the treatments. Crude protein and lipid levels of floating (good) and sinking (bad) eggs collected in February to March 1992, and August to September 1992 were similar in all treatments. Unfed larvae from treatment 1 survived until the fifth day after hatching while those in the control and treatment 2 groups lasted only until the third day. These results suggest that supplementation of cod liver oil and SELCO in the trash fish diet of E. suillus broodstock does not influence egg production, fertilization and hatching rates, and egg quality.
    • 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.
    • Article

      Feed preference of milkfish (Chanos chanos Forsskal) fry given different algal species as natural feed 

      JB Pantastico, JP Baldia & DM Reyes Jr. - Aquaculture, 1986 - Elsevier
      Acclimated milkfish fry (mean wet weight, 6.0 mg) were fed with unialgal cultures of five species of freshwater algae: Oscillatoria quadripunctulata, Chroococcus dispersus, Navicula notha, Euglena elongata and Chlorella ellipsoidea. In the first experiment, the filamentous blue-green alga, Oscillatoria, appeared most acceptable to milkfish fry throughout the growing period, while feeding milkfish fry with the unicellular species, Chroococcus, resulted in lower weights and survival. In the second experiment, increases in weight of milkfish fry fed with Oscillatoria alone or in combination with Chroococcus were comparable. However, a significant increase in survival was obtained with the combination feeding. A third experiment showed that high density cultures of Oscillatoria resulted in significantly large weight increments in all growth stages. The other algae tested did not support growth of milkfish fry.

      14C-Labeled algae of the same species were fed to milkfish fry. Significantly high assimilation retes were observed in almost all growth stages of milkfish fry with Oscillatoria alone or Chroococcus alone. Negligible amounts of Navicula, Chlorella and Euglena were assimilated.
    • Article

      Fry to fingerling production of Tilapia nilotica in aquaria using phytoplankton as natural feed 

      J Pantastico, C Espegadera & D Reyes - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Overall results of the study indicate that the availability of high concentrations of phyloplankton in the rearing medium favoured growth of T. nilotica fry to fingerling.
    • Article

      Fry-to-fingerling production of Tilapia nilotica in aquaria using phytoplankton as natural feed 

      JB Pantastico, C Espegadera & D Reyes - Kalikasan, The Journal of Philippine Biology, 1982 - University of the Philippines at Los Baños
      Two experiments were conducted to demonstrate the efficiency of phytoplankton as natural feed in fry-to-fingerling production of Tilapia nilotica . In the first experiment, growth and survival rates of fry given a sustained supply of algae increased considerably over the control fed with rice bran. In the second experiment, T. nilotica were grown in "green" water with phytoplankton concentrations adjusted to the following densities (cells/ml): high, 150-175 x 10 super(3); moderate, 90-120 x 10 super(3); and low, 50-60 x 10 super(3). Increasing the algal densities in the rearing medium enhanced growth of fry. Highest weight increments were obtained with high and moderate phytoplankton concentrations.
    • Article

      Hatchery rearing of sea bass Lates calcarifer Bloch 

      MM Parazo, DM Reyes Jr. & EM Avila - The Philippine Scientist, 1991 - Science and Technology Information Institute
      A hatchery rearing scheme for sea bass (Lates calcarifer Bloch) is described. Survival rate from hatching (d0) to harvest (d30) was 34%. Feeding sea bass fry with Chlorella-fed or Selco-enriched instar II Artemia from d19 to d23 resulted in similar survival rates (74%), total length (8.2 and 8.9 mm) and weight (8.9 and 12.1 mg) at d30. Although sea bass fry fed 2.5, 5 or 10 Artemia/ml/day from d14 to d20 exhibited similar survival rates (73-93%), fish were significantly larger as feed density increased (7.1, 8.2, 9.8 mm total length and 2.4, 4.3, 9.7 mg wet weight, respectively). The significance of this study lies in providing technical information on artificial production of sea bass fry.
    • Article

      HCG and LHRH-A induced spawning in bighead carp Aristichthys nobilis Rich. reared in floating cages in Laguna de Bay 

      AC Fermin & DM Reyes Jr. - The Philippine Scientist, 1989 - San Carlos Publications, University of San Carlos
      Hormone-induction of spawning in bighead carp Aristichthys nobilis Rich. by single or double intraperitoneal injection with varying combined dosages of HCG and LHRH-A was conducted. Fish were spawned successfully following a single or double injection with 1800 to 2000 IU HCG in combination with 10, 15 or 20 µg HRLR-A per kg body weight. Fish injected with lower dosages of HGC at 1200 or 1500 IU/kg body weight plus 20 µg/kg LHRH-A did not differ significantly (P>0.05). Fish given a single injection ovulated after 12.0 ± 0.1 hours. No significant difference was found in the total number of eggs spawned per fish among the injection protocols (P>0.05). However, lower fertilization and hatching rates of eggs were observed in fish that spawned spontaneously in the tank as compared to those fish whose eggs were stripped and dry-fertilized (P<0.05).
    • Article

      Induction of sex change in female Epinephelus coioides by social control. 

      GF Quinitio, NB Caberoy & DM Reyes Jr. - The Israeli Journal of Aquaculture-Bamidgeh, 1997 - Society of Israeli Aquaculture and Marine Biotechnology
      Mature female groupers (Epinephelus coioides) of different sizes were stocked in three floating net cages (2 fishes each) and in tanks (2-4 fishes) to induce sex change in the bigger female grouper after isolation from the original group. All the bigger fish (initial body weight 5.0-6.1 kg) in the floating net cages changed into males by the end of the experiment, while the smaller ones (initial body weight 4.5-5.2 kg) remained female. The fastest sex change was in cage 1 where the bigger fish had atretic oocytes one month after stocking and was milting after four months. In the other cages, milt production in the bigger fish was observed 6-10 months after stocking. In the tank-reared groupers, the biggest fish (initial body weight 6.4 kg) in the tank with four fishes was found to be milting about two months after stocking while the smaller fishes (initial body weight 3.4-4.0 kg) were still females. The fishes started to spawn two months later. In another tank that was stocked with two females, no sex change was observed in the bigger fish even 16 months after stocking. These results indicate that female groupers can be sexually changed into male by social control at the shortest period of four months in floating net cages and two months in tanks. However, there may be cases wherein sex change will not occur.
    • Article

      Isolation and cultivation of Anabaena sp. from organic media after sterilization 

      JB Pantastico, JP Baldia, SF Baldia, DM Reyes Jr. & AC Gonzal - Philippine Agriculturist, 1986 - University of the Philippines at Los Baños
      A species of Anabaena was isolated from the fronds of Azolla pinnata by combining the chopped fronds of the Azolla extract with either lake water or an organic medium (duck manure alone or combined with banana stalk) and sterilizing at 121°C and 15 psi for 20 min. Growth of Anabaena sp. was observed within 33 to 37 days and compared with the morphology of A. azollae squeezed from the fronds of Azolla pinnata. Results were discussed regarding the high temperature tolerance of the recently isolated Anabaena sp. Anabaena sp. was incubated in synthetic sponge carriers and grown in different media. The total nitrogen contributions of Anabaena sp. in lake water and in nitrogen-free inorganic medium was 22.3 and 13.2 mg/l respectively after 60 days.
    • Article

      Multiple gonadal maturation and re-maturation after hormone-induced spawning in bighead carp Aristichthys nobilis Rich. 

      AC Fermin, MA Laron & DM Reyes Jr. - The Philippine Scientist, 1991 - San Carlos Publications, University of San Carlos
      Gonadal maturation and rematuration after hormone-induced spawning in cage-reared female bighead carp Aristichthys nobilis were observed. Percent maturation ranged from 54 to 100% for females and 0 to 40% for males. Maturation rates in either sex were high during March (1988) and low during December (1987). No significant differences were observed for monthly mean oocyte diameters ranging from 1.41 to 1.51 mm. Of the 34 females injected with LHRH-a, Domperidone or HCG, either singly or in combinations, 12 females spawned successfully. Three females were spawned twice consecutively at intervals between 71 and 107 days. Fish possessed oocytes of similar characteristics as those obtained from pre-spawning females when sampled after 27 days from spawning. Generally, oocyte diameters of individual fish measured before the first spawning (range: 1.41 to 1.53 mm) were not significantly different from those measured during the succeeding spawnings (range: 1.38 to 1.49 mm). Physico-chemical and biological parameters in the lake did not influence maturation except for zooplankton.
    • Book

      Sea bass hatchery operations. 

      MM Parazo, LMB Garcia, FG Ayson, AC Fermin, JME Almendras, DM Reyes Jr., EM Avila & JD Toledo - 1998 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 18
      The manual addresses sea bass (Lates calcarifer) fry production in the hatchery. It describes the principles and practical procedures for rearing sea bass - from eggs until metamorphosis - as practiced by the SEAFDEC Aquaculture Department in Tigbauan, Iloilo, Philippines. It is presented under the following main section headings: General principles; biology; Selecting a suitable site; Design - tank systems, seawater supply system, freshwater supply system, aeration system, other facilities; Broodstock - source of breeders, breeding techniques; Egg collection, transport and hatching; Larval rearing - stocking density, feed types and feeding management, water management size-grading of larvae; Harvest and transport of fry; and, Propagation of larval food - Chorella, Brachionus, Artemia, Moina.
    • Article

      Size- and weight-dependent cannibalism in hatchery-bred sea bass (Lates calcarifer Bloch) 

      MM Parazo, EM Avila & DM Reyes Jr. - Journal of Applied Ichthyology, 1991 - Blackwell Publishing
      The relationship of predator size to maximum prey size, and predator weight to weight of prey consumed among cannibalistic sea bass (Lates calcarifer Bloch) in a hatchery were assessed. Maximum prey size was computed from morphological measurements (predator mouth width, prey body depth and fish total length), while prey consumption was determined from predators kept in experimental beakers and fed only prey sea bass for a 7-day period. Maximum prey size was 61–67 % of predator total length (TLprey = 0.5944 TLpredator+ 0.0724). Gut dissection of predators showed that size of ingested prey increased with increasing predator size not exceeding the maximum size limit indicated by the above equation. Daily prey consumption of predators in the beakers was expressed as WPrey = -0.2407 Wpredator+ 0.7697Wpredator-0.1141. During hatchery rearing of sea bass, fish with length differences of more than 33 % must be separated and food of appropriate size provided to limit cannibalism.
    • Conference paper

      Survival of yolk-sac larvae of grouper (Epinephelus suillus) under simulated transport conditions. 

      GF Quinitio, JD Toledo, AT Duller & DM Reyes Jr. - In P Lavens, P Sorgeloos, E Jaspers & F Ollevier (Eds.), Larvi '91. Short Communications and Abstracts of Contributions Presented at the International Symposium on Fish and Crustacean Larviculture, 27-30 August 1991, Gent, Belgium, 1991 - European Aquaculture Society. EAS Special Publication No. 15
      Transport of live fish is a routine activity in aquaculture. Various transport techniques have been reported by Berka. Transport of grouper eggs (Epinephelus suillus) between fisheries stations in Thailand is being conducted. However, no report has been made on transport of yolk-sac larvae of this fish. In the Philippines transport of eggs poses difficulties, particularly for hatcheries which are distant from the broodstock rearing site since spawning occurs between 1600 and 1800 h. Eggs can only be collected the following morning and hatching starts around 1200-1300 h (20 h after fertilization). Thus it seems advisable to transport yolk-sac larvae rather than eggs of grouper under such conditions. This study was conducted to determine the feasibility and optimum loading density of transporting grouper yolk-sac larvae for about 2 h.
    • Article

      Survival of young rabbitfish (Siganus guttatus Bloch) under simulated transport conditions 

      FG Ayson, MM Parazo & DM Reyes Jr. - Journal of Applied Ichthyology, 1990 - Blackwell Publishing
      The effect of loading density, transport duration, water temperature, and salinity on survival of young rabbitfish (Siganus guttatus Bloch) under simulated transport conditions was investigated. The rocking motion of transport was simulated by an electric shaker. At ambient temperature and salinity (28°C/32‰S) increasing loadin density and transport duration resulted in decreasin fish survival rates. When both temperature ant salinity (20°C/20‰S) were lowered survival improved sinificantly. Dissolved oxygen, water temperature, and salinity were critical factors affecting survivaf of young rabbitfish during simulated transport. Based on the results, a density of 100 fish/L can be packed for 8 hours of transport and 300 fish/L for 2 hours at 28°C and 32‰, and about 200 fish/L for 4 hours at 20°C and 20‰S.
    • Article

      Tilapia (T. nilotica) and Azolla (A. pinnata) cage farming in Laguna Lake 

      JB Pantastico, SF Baldia & DM Reyes Jr. - Fisheries Research Journal of the Philippines, 1986 - Fisheries Research Society of the Philippines
      Four batches of Azolla were grown in cages in Laguna lake between 1981 to 1983. Percent increase in weight per day ranged from 35% (Feb. 24 - March 2, 1981) to 5% (May 8 - May 12, 1983.) Best growth was attained during the cold months.

      Acceptability of Azolla as supplemental feed for tilapia was determined in four experiments conducted between 1981-1984. The stocking densities varied in the four experiments: 25/m2, 50/m2, 100/m2 and 150/m2. All the results showed increase in mean weight of tilapia fed with fresh Azolla over the unfed control. Statistical analysis showed significantly high (p<0.05) mean weights of tilapia fed with Azolla in two experiments only.