Now showing items 1-20 of 125

    • Article

      A comparative study of various extenders of milkfish, Chanos chanos (Forsskal) sperm preservation 

      S Hara, JT Canto Jr. & JM Almendras - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Four chemical extenders in 7 different concentrations (potassium chloride, sodium chloride, glucose, sodium citrate, Ringer s solution, cow serum and milkfish (Chanos chanos) serum) were compared in the preservation of milkfish sperm. Results showed milkfish serum to be the most suitable of the various extenders tested. This may be attributed to suitable osmotic potential and/or presence of proteins which may have directly or indirectly influenced sperm viability. The effects of milkfish serum on the motility and fertilizing capacity of sperm at different durations of storage however need to be investigated.
    • Article

      A comparison between the catching efficiency of two milkfish fry collecting gears and their respective modifications 

      GF Quinitio & G Kawamura - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An experiment was conducted along the shore of Culasi, Antique in Panay to compare the milkfry (Chanos chanos) catching efficiency of the ordinary fry seine against its innovation and the ordinary sweeper against its 2 modifications. Results show that it is possible to replace the wings of the presently used sweeper and the ends of the fry seine with a coarse-meshed netting. This improvement decreases the water resistance of the gears and thus enables fry gatherers to use larger ones thereby giving more catch.
    • Article

      A preliminary study on the growth and survival of stunted and non-stunted milkfish fingerlings 

      MN Lijauco, EG Griño, DD Gerochi & EM Rodriguez - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A study was conducted comparing the growth of stunted and non-stunted milkfish.
    • Article

      A statistical index of growth condition in an aquaculture experiment 

      RH Tan & IE de Mesa - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A simple statistical index, for evaluating the condition of growth in an aquaculture experiment and indicating the extent of effect of any plausible rival hypothesis, is presented.
    • Article

      Acute toxicity of un ionized ammonia to milkfish (Chanos chanos) fingerlings 

      ER Cruz - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings was determined using a static bioassay system. Median lethal concentrations found show that milkfish fingerlings have a high tolerance to ammonia and it is unlikely that levels as high as those employed for the acute exposure would be found to occur under natural conditions. Although the threat of acute toxicological effects induced by ammonia are remote, such conditions might be encountered in stressed natural environments or in heavily loaded aquaculture systems.
    • Article

      Acute toxicity of unionized ammonia to milkfish (Chanos chanos Forsskal) fry 

      NA Jumalon - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Amino acid analysis of P. monodon muscle 

      FF Catedral & VA Dy-Peñaflorida - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Figures for the amino acid composition of Penaeus monodon, are tabulated, and compared to those for white tuna meat.
    • Article

      Attractants in purified diets 

      FP Pascual - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Juvenile Penaeus monodon were reared on purified diets containing different attractants used to gelatinize the cornstarch: plain water, shrimp, mussel, squid or trash fish extract. The highest survival rate was observed in the group given the shrimp attractant, followed by mussel, fish and squid. However growth appeared best in the diet containing mussel extract. Mussel extract apparently can be used to enhance the attractability of purified diets.
    • Article

      Bacteria from seawater used in Penaeus monodon larval cultures 

      AT Llobrera & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Bacteria in the seawater used in P. monodon hatchery operations were isolated on Bachmann's agar. The total plate counts in 25 isolations ranged from 1.0 - 5.0 x 102 to 5.1 -10.0 x 105 cells per ml. Out of 124 isolates, 98 (79 percent) were Gram-positive and 26 (21 percent) were Gram-negative. Micrococcus and Staphylococcus were dominant in the former group, while Acinetobacter, Moraxella, Flavobacterium and Alcaligenes were most numerous in the latter. Twenty-nine of the Gram-positive isolates closely resembled Peptostreptococcus, Planococcus, and Pediococcus.
    • Article

      Bioenergetics of the freshwater prosobranch Idiopoma angularis Muller in Laguna de Bay 

      EA Baluyut - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      This study was made as an attempt to investigate some of the ecological aspects of the freshwater snail Idiopoma angularis Muller in a modern framework of energy flow and mathematical models. It offers the first investigation of respiration (as related to temperature and body size), production (growth), and excretion in the prosobranch I. angularis in Laguna Lake.
    • Article

      The biology and control of Caligus sp., an ectoparasite of the adult milkfish Chanos chanos Forskal 

      EM Laviña - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      One unidentified species of copepod belonging to the genus Caligus of the family Caligidae was found to infest the adult milkfish broodstock. To control the parasites infesting the adult milkfish, tests were made using the chemical (2,2,2-trichloro-1-hydroxyl)-phosphonic acid-dimethylethol (Neguvon) at a concentration of 0.25 ppm. It is noted that a concentration of 0.25 ppm of Neguvon maintained for 12-24 hours in the sabalo-containing tanks in a closed water system but with aeration is effective in controlling the parasites. Fish mortality during the experiment was due to inadequate aeration in the tanks.
    • Article

      Biology and farming of the green mussel Mytilus smaragdinus 

      WG Yap, C Orano & M Tabbu - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Biological investigations were carried out in Sapian Bay, Capiz from November 1975 to December 1976 with samplings conducted fortnightly. Histological studies on the gonad reveal a high percentage of ripe and spent females during the month of April and May, and ripe to near ripe during November to December. However, larval counts were highest on February 25, 1976 with 253 mytilid larvae per haul compared to 0-79 per haul during all other months. The high larval count was followed by the highest spat settlement during the next sampling period two weeks later, with the spat collector set in the water during the February 25 sampling. The four materials tested, blue polypropylene fiber rope, black polypropylene fiber, and coir rope, all had their highest spat counts during this period with an average of 471 spats per standard 10 cm rope piece. The range during the other time periods is 2-283 spats. Of the 4 materials tested, the black fibrillated polypropylene film had the highest larval counts in 15 out of a total of 25 sampling periods. The blue rope was the poorest spat collector. Coconut husk was tested later on and it proved to have a very high catchability, with spats completely enveloping the husk surface. Growth monitored from one cohort in Sapian Bay averaged 10 mm per month. 50-60 mm is considered marketable size. Trial growth experiments with transplanted mussels were also conducted at Igang Bay in Guimaras Island, Makato River in Aklan, and a milkfish pond in Leganes, Iloilo. Survival in Igang was less than 50% after the second week, and the condition of the surviving mussels can be described only as watery with the mantle completely transparent. Mortality was minimal in Makato but the growth rate was only 30% that of Sapian Bay. The pond experiments were terminated due to severe crab predation.
    • Article

      Catch composition of penaeid prawns caught with fish corrals at Batan Bay, Philippines 

      H Motoh, N Solis & E Caligdong - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Changes in length and weight of milkfish fry preserved in formalin 

      S Kumagai & N Castillo - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fry shrank immediately after they were preserved in formalin, but from the second week onwards shrinkage was almost nil. Fry in freshwater formalin solutions shrunk less than those in seawater formalin solutions. It is recommended that milkfish Chanos fry be preserved in formalin solutions for 1 wk prior to length measurement and at least for 3 wks before determining body weight.
    • Article

      Courtship and mating behavior in Penaeus monodon Fabricius 

      JH Primavera - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An illustrated description is given of the courtship and mating behaviour of P. monodon. Courtship and mating follow three distinct phases: (1) parallel swimming of male and female from the bottom to a height of 20-40 cm over distances of 50 to 80 cm; (2) male turns ventral side up to female; and (3) male turns perpendicular to female, arches body around the female and lifts head and tail. Mating is believed to take place generally at night, following moulting of the female. On the basis of thelycum structure and mating pattern, Penaeus may be divided into two groups: (1) those with a close thelycum in which mating follows moulting, such as P. merguiensis and P. monodon; and (2) those with open thelycum where mating takes place immediately preceding spawning, as in P. stylirostris and P. vannamei.
    • Article

      Culture experiments on the copepod, Tisbintra elongata MORI, and evaluation of that species as food organism for milkfish larvae 

      S Yamasaki & J Canto Jr. - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Five types of food were used to culture T. elongata: rice bran, cow dung, bread, cow dung, bread yeast, fermented fish solubles and Spirulina. Bread yeast was found to give the highest densities. An evaluation was also made of the effectivity of rice bran and fermented fish solubles for the outdoor mass culture of T. elongata . A comparative study on the growth and survival rate of milkfish fry (Chanos chanos) fed with T. elongata and Artemia showed there to be no significant differences between the diets.
    • Article

      Culture of grey mullet, Mugil cephalus, Linnaeus in brackishwater ponds at two stocking densities 

      DD Baliao, EM Rodriguez & DD Gerochi - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The culture potential of hatchery-produced grey mullet (Mugil cephalus , Linnaeus) stocked with average weight of 3.7 g and at 2,500 (treatment I) and 3,000 (treatment II) fingerlings/ha in six 350m brackishwater ponds following the lab-ab method of culture was studied.
    • Article

      Culture of the mud crab, Scylla serrata (Forskal) at different stocking densities in brackishwater ponds 

      DD Baliao, EM Rodriguez & DD Gerochi - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The mean weight percentage survival, relative growth increment, net production and feed conversion value of S. serrata stocked in monoculture at different stocking densities are presented.
    • Article

      Developmental and ecological stages in the life history of milkfish Chanos chanos Forsskal 

      P Buri, S Kumagai, V Bañada, A Triño & N Castillo - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Seven stages in the life history of the milkfish C. chanos , are recognized and suggested: A, embryonic; B, yolksac larval; C, larval; D, postlarval; E, juvenile; F, subadult; G. adult. An outline is presented of the life history. It is concluded that the milkfish, throughout the known stages of their life history are well adapted and equipped for optimal survival. High swimming performance, broad flexibility in feeding habits, high adaptability to a wide range of physicochemical conditions of the environment are but a few of the adaptations. The main driving force in all developmental stages is the evolutionary response to food distribution and availability followed by predation pressure.
    • Article

      Diel fluctuations in catch of the postlarval Penaeus japonicus group 

      H Motoh, N Solis & M Gelangre - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Experiments were undertaken in order to measure the diel fluctuations in the catch of the post-larvae of P. japonicus in relation to the tidal cycles, light conditions and water temperature. The fluctuations are discussed comparing them with other post-larvae Penaeus species appearing along shore waters in the Philippines.