Now showing items 1-6 of 6

    • 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.
    • Article

      An assessment of algal growth in net cages in Laguna Lake 

      JB Pantastico & JP Baldia - Fisheries Research Journal of the Philippines, 1981 - Fisheries Research Society of the Philippines
      Quantitative determination of the algal population, in terms of cells/ml and biomass/ml, was conducted during the first month of growing P. monodon postlarvae in Laguna Lake. Algae were sampled from each side of net cages at depths of 15, 30 and 45 cm below the water surface. Accumulation of algae appeared to be influenced by the direction of water flow. Moreover, growth of algal species was inversely proportional to depth of water. After two weeks, algal biomass was estimated to reach 4.5 kg per cage (1 x 1 x 1 m).

      Diatoms (Chrysophyta) predominated throughout the experimental period followed by members of Cyanophyta and Chlorophyta.
    • Conference paper

      Efficiency of some cyanophytes as larval feed for silver carp (Hypophthalmichthys molitrix) and the culture of Spirulina platensis 

      JB Pantastico, SF Baldia & JP Baldia - 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
      Six-day old carp (Hypophthalmichthys molitix) fry (mean weight 3 mg) were stocked at 5/l in aquaria. These were fed with unialgal cultures of three species of blue-green algae, namely: Anabaena sp., Oscillatoria quadripunctulata and Spirulina platensis. Best increase in weight was obtained when feeding consisted of Spirulina followed by those fed with Oscillatoria. Poor results were obtained when fry were fed solely with Anabaena. Weight gain was highest during the first two weeks with Spirulina as feed. On the other hand, survival of fry was higher (68%) with Oscillatoria than with Spirulina (54%). Proximate analysis of fish and algae were conducted. Spirulina seemed to be the most promising live food organism for larval rearing of silver carp. Thus, laboratory culture of the cyanophyte at different pH (9, 10 and 11) and two types of media (hog manure and urea) were investigated. Algal biomass production in a semi-continuous, outdoor tank system was also determined.
    • 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

      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.