Now showing items 1-5 of 5

    • Article

      Effects of temperature on behavior, growth, development and survival in young milkfish, Chanos chanos (Forskal) 

      AC Villaluz & A Unggui - Aquaculture, 1983 - Elsevier
      Effects of three temperature treatments on activity, feeding, growth, development and survival of young milkfish (Chanos chanos) were investigated. Low temperature (<22.6°C) and hypoxial condition (<1 ppm O2) decreased activity, responsiveness and food intake; high temperature (up to 33°C) had the opposite effect. Growth and development were fastest in fish maintained in high temperature (x = 29.5°C). Fish in low temperature (x = 20.7°C) had the least growth and were inhibited from developing into juveniles during the 3-month period. Highest survival (x = 99.7%) was obtained in high temperature but was not significantly different (P>0.05) from ambient temperature (x = 97.7%).
    • Article

      Effects of temperature on behavior, growth, development and survival of young milkfish, Chanos chanos Forsskal 

      AC Villaluz & A Unggui - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The effects of 3 temperature treatments on activity, feeding, growth, development and survival of young milkfish (Chanos chanos) were investigated under laboratory conditions. It is believed that the results may be applied to develop a land-based mass production technology in rearing milkfish fry to fingerlings.
    • Article

      Growth of juvenile milkfish Chanos chanos in a natural habitat 

      S Kumagai, TU Bagarinao & A Unggui - Marine Ecology Progress Series, 1985 - Inter Research
      A population of juvenile milkfish, C. chanos (Forsskaal) was studied in a small mangrove lagoon in Naburut Island, central Philippines. Several size groups of milkfish occurred in the lagoon as a result of its periodic connection with the sea. Body-weight to fork-length relation was: log W = - 5.2991 + 3.2388 log L, similar to that of pond-cultured specimens. In Naburut lagoon, juvenile milkfish take in primarily blue-green algae, as well as mangrove and seagrass debris, diatoms and detritus. The condition factor of fish caught during the day from May to Nov. stayed constant, indicating that lagoon conditions for growth in terms of food did not change markedly during the year. The monthly size-frequency distribution shows that juvenile milkfish in the lagoon grew at a rate of 7 to 9 mm wk super(-1) in 1979. Compared with pond-cultured specimens, their growth rate was lower during the first month but higher during the second month in the nursery. The limited area and depth of Naburut lagoon probably set the limit to the size of juvenile milkfish; these can be sustained there to just 150 to 180 mm fork length.
    • Technical Report

      A study on the milkfish fry fishing gears in Panay Island, Philippines 

      S Kumagai, T Bagarinao & AS Unggui - 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Technical report / SEAFDEC Aquaculture Department; no. 6
      This study was conducted to obtain information for evaluating the present fry fishing practices and for understanding the behaviour of the fry. A description of the milkfish, Chanos chanos, fry fishing gears is presented. Each gear is illustrated and its operation explained.
    • Book chapter

      Transplantation, hatchery, and grow-out of window-pane oyster Placuna placenta in Guimaras and Iloilo 

      SS Garibay, SN Golez & AS Unggui - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      The windowpane oyster Placuna placenta (local name kapis) used to be harvested in large quantities and support a shellcraft industry in the Philippines, particularly in Panay Island. But the fishery and the industry declined markedly by the 1990s. Studies were conducted to transplant kapis and also to develop hatchery techniques for it in an effort to counter the population depletion. Kapis with average shell heights of 7 cm and 10 cm were transplanted from Roxas City in northern Panay Island and from Oton, Iloilo in southern Panay to Taklong Island in Guimaras during the rainy season (July–November) and the dry season (February–June). Survival of the transplants was higher during the dry season (57–60%) than during the rains (35–48%). Sexually mature kapis 10 cm in shell height were induced to spawn by temperature manipulation, water level manipulation, and use of ultravioletirradiated sea water. Spawning was successfully induced by raising the water temperature to 29±0.5oC. Eggs measured 45 μm on average, and fecundity was 5,000–10,000 per female. Kapis larvae were reared on a combination of the microalgae Isochrysis galbana, Tetraselmis sp., and Chaetoceros calcitrans, maintained at a density of 100,000 cells/ml. Three water treatment schemes were tested for larval rearing: chlorination, ultraviolet irradiation, and filtration (control). Larvae survived to the umbo veliger stage (180 μm, day 10) in chlorinated sea water whereas mass mortality occurred at the straight-hinge stage (days 4–) in both UV-treated and filtered sea water.