Browsing by Author "Baldia, Susana F."
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 SocietySix-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.
Growth responses of Spirulina platensis to some physico-chemical factors and the kinetics of phosphorus utilization SF Baldia, K Fukami, T Nishijima & Y Hata -
Fisheries Science, 1995 - Japanese Society of Fisheries ScienceThe growth responses of Spirulina platensis NIES-46, a brackishwater strain originally isolated from Lake Texcoco Mexico, to some physico-chemical factors and nutrients were investigated. The optimum conditions for growth were the following: light intensity of 160 µE m-2 sec-1, temperature of 30°C, pH 10, and chlorinity of 0.55‰. NIES-46 strain could utilize both inorganic and organic phosphorus sources. Values on the different growth parameters for orthophosphate and other organic phosphorus sources were as followings: half-saturation constant of 0.02-0.07 mg-P/l; maximum growth rate of 0.8-1.0/d; minimum cell quota of 0.08-0.32 pg-P/cell, and level for saturated growth yield of 0.3-1.0 mg-P/l. The result that this species utilized effectively a rather wide range of both inorganic and organic phosphorus and showed a high growth rate suggests that mass production of this species is possible by recycling organic waste.
ArticleJB Pantastico, JP Baldia, SF Baldia, DM Reyes Jr. & AC Gonzal -
Philippine Agriculturist, 1986 - University of the Philippines at Los BañosA 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.
ArticleSF Baldia, MCG Conaco, T Nishijima, S Imanishi & KI Harada -
Fisheries Science, 2003 - Japanese Society of Fisheries ScienceThe amount of microcystin in Microcystis aeruginosa bloom was investigated during the rainy season of 1999 in Laguna de Bay, the Philippines. Bloom samples taken from the West Bay and East Cove stations of the lake were studied in relation to the characteristics of environmental conditions. Four types of microcystins, microcystin-LR (MC-LR), microcystin-RR (MC-RR), 6(Z)-Adda-microcystin-RR, and 3-desmethylmicrocystin-LR were identified from the natural bloom samples among which MC-LR was the most dominant type of microcystin. Production of microcystin (88.6 µg/100 mg dried cells) was highest during the first sampling week that coincided with high water transparency and high conductivity. The occurrence of a strong typhoon during the second sampling week had changed the environment drastically, which was characterized by low water transparency, high turbidity, low water temperature, and with trace amounts of MC-LR detected at the East Cove station. Thus, toxin production over time as well as the relationship between Microcystis production and toxin concentration could not be fully evaluated.
Milkfish (Chanos chanos) fingerling production in freshwater ponds with the use of natural and artificial feeds Milkfish fry were reared to fingerling size in freshwater ponds. For the first experiment, fish were fed the blue-green algae Oscillatoria inoculated and grown in the ponds, Oscillatoria supplemented with a fishmeal-based formulated diet, and the formulated diet alone. Twelve 50-m2 earthen ponds were prepared to enhance growth of the indigenous natural foods. Acclimated wild milkfish fry were stocked randomly at 90/m2 and were fed for 6 weeks. Milkfish fed the formulated diet alone had a significantly higher (P<0.05) mean weight gain (1.314±0.201 g) than milkfish given the combination of Oscillatoria and formulated diet (0.882±0.230 g). Growth was lowest for fish fed Oscillatoria alone. The feeding treatments in the second experiment were: combination of Spirulina powder and formulated diet, formulated diet alone, and rice bran alone. The stocking rate was equivalent to 91.5–92.5 fry/m2 and feeding lasted for 7 weeks. All feeds promoted some growth but the milkfish fed the formulated diet alone invariably had the highest weight increment (1.504±0.167 g), followed by fish given the feed combination (0.881±0.140 g). Rice bran alone gave the lowest growth response. For both pond experiments, growth trends of the young milkfish were similar to those grown under laboratory conditions. Although survival rates were significantly different in one aquarium experiment, survival rates of milkfish in ponds did not differ significantly (P>0.05) among treatments.