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    • Article

      The effects of water hardness on the hatching and viability of silver carp (Hypophthalmichthys molitrix) eggs 

      AC Gonzal, EV Aralar & JMF Pavico - Aquaculture, 1987 - Elsevier
      An investigation was conducted to establish water hardness concentration for optimum hatching of silver carp (Hypophthalmichthys molitrix) eggs. Eggs were incubated for 19 h at 26.5°C at six levels of water hardness: 100, 200, 300, 400, 500 and 600 mg/l CaCO3. Water absorption at 100–200 mg/l CaCO3 caused eggs to burst prematurely and minimal water absorption occurred at 600 mg/l CaCO3. Chloride concentration at 0 and 6 h post-fertilization was significantly related to egg hatchability. Total ammonia-nitrogen at 6 h, pH at 6 h, magnesium hardness at 18 h and chlorides at 18 h significantly influence viability of larvae. A water hardness of 300–500 mg/l CaCO3 is recommended for the successful hatching of silver carp eggs.
    • Article

      Limnological features of Lake Buluan: Preliminary findings and observations 

      WG Yap, EA Baluyut & JMF Pavico - Fisheries Research Journal of the Philippines, 1983 - Fisheries Research Society of the Philippines
      A limnological survey of Lake Buluan in Mindanao was conducted to evaluate its potentials for fishpen and fish cage culture. The lake was found to be shallow and highly productive, with the major physicochemical and biological parameters within ranges favorable for fish production.

      The lake has high gross primary production values attributable to high densities of phytoplankton, primarily blue-green algae. It has a high annual yield of 10,000 mt of fish, which when divided by its area of 6,000 hectares, gives an average production of 1.64 mt/ha/yr - the highest open water catch in the Philippines and in Southeast Asia today.