Now showing items 1-9 of 9

    • Conference paper

      Breeding and culture of the polychaete, Marphysa mossambica, as feed for the mud crab 

      VR Alava, JB Biñas & MAE Mandario - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Marine worms (Annelida: Polychaeta) are considered as important food for crustacean broodstock because they contain hormones and correct balance of essential nutrients for reproduction. Marphysa mossambica (Peters, 1854) occurs in muddy coastal areas and is abundant in fish farms where it builds burrows in nutrient-rich sediments. This species encapsulates their eggs and larvae in gelatinous masses (jelly cocoons). It is a multiple spawner, and breeders are repeatedly spawning in tanks. Culture techniques have also been developed and established in tanks. Based on dry weight, cultured M. mossambica contained 62-66% crude protein and 7-12% lipids with levels of highly unsaturated fatty acids (HUFAs) such as arachidonic (20:4n-6), eicosapentaenoic (20:5n-3) and docosahexaenoic acid (22:6n-3) at 0.2-0.5%, 0.2-0.3% and 0.3-0.5%, respectively. Stocks were monitored for the presence of white spot syndrome virus (WSSV) using polymerase chain reaction-based diagnostic methods. The WSSV-free polychaetes mass-produced in tanks were utilized as live food for mud crab S. serrata broodstock. Mud crab broodstock fed natural food (mussel, fish, and squid) with live Marphysa on daily feed rotation produced higher number of crab zoeae, larval survival, total lipids and HUFAs than those fed natural food without live Marphysa. Production of nutrient-rich WSSV-free polychaetes in captivity can play a significant role in supporting crustacean hatcheries that supply seeds to the nursery and grow-out.
    • Article

      Effect of nitrite, ammonia, and temperature on P. monodon larvae 

      FF Catedral, DD Gerochi, AT Quibuyen & CM Casalmir - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      P. monodon larvae were studied for the effects of temperature, ammonia, and nitrite on survival. Toxicity levels of nitrite were found to vary with larval stage. Larvae could tolerate ammonia up to about 10 ppm, with the effect more clearly shown by the zoea stage. Survival and growth were not significantly affected by temperature, although moulting was enhanced at temperatures higher than 29°C. Larvae of P. monodon have lower tolerance toward nitrite and ammonia compared to postlarvae. Although high survival was obtained at low levels of nitrite and ammonia, it is still necessary to know their effects on metabolism, in order to examine possible biochemical parameters for diagnosing sublethal toxicity or stress.
    • Article

      Effect of some physico-chemical factors on the survival and growth of Penaeus monodon postlarvae 

      FF Catedral, R Coloso, N Valera, CM Casalmir & AT Quibuyen - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Growth and survival rates of P. monodon postlarvae were examined at different temperatures, salinities, and nitrite and ammonia concentrations, using one feed level. Condition of postlarvae greatly affected the experimental results shown in some instances where very low survival rates were obtained, even for the controls. Results indicated that postlarvae from P10 and up can tolerate salinity changes of 10 to 20 ppt without prior acclimation. Survival generally appears the same for temperatures between 24 and 36°C. It appears that P. monodon postlarvae have higher temperature tolerance. Tolerance of postlarvae at the early postlarval stage is between 30 and 50 ppm of nitrate. They were more tolerant from P10 upwards. Although survival was high in runs containing nitrite, growing appears to have been affected. Postlarvae could tolerate ammonia concentrations up to about 50 ppm. At 100 ppm higher mortality rates were observed. Whether or not there was any permanent effect by nitrate and ammonia at high but apparently tolerable levels is not known.
    • Article

      Isolation and culture in artificial media of Lagenidium from Penaeus monodon larvae 

      MCL Baticados, GL Po, CR Lavilla & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fungal infection of P. monodon larvae is a problem in hatchery operations. The fungus, which attacks the nauplius to postlarval stages and causes up to 100% mortality, has been tentatively identified as belonging to the genus Lagenidium. This pathogenic organism has recently been isolated and cultured. A description is given of the fungus, and features of its biology and pathology are discussed.
    • Article

      Laboratory breeding of the mud crab Scylla serrata (Forskal) through the zoea and megalopa stages to the crab stage 

      H Motoh, D de la Peña & E Tampos - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A series of experiments is being conducted to establish breeding techniques to mass-produce seedlings of S. serrata for pond cultivation to meet the commercial demand for the crab. The objective is to culture the crab through the 5 zoea stages and 1 megalopa stage to the crab stage. A brief resume of the experiments is presented. Heavy mortality occurred at the 1st, 2nd and 5th zoea stages, and during the megalopa stage. Initial mortality is attributed to unfavourable rearing conditions, and later mortality to cannibalism.
    • Article

      Larvae of decapod crustacea of the Philippines - I. The zoeal stages of a swimming crab, Charybdis cruciata (Herbst) reared in the laboratory 

      H Motoh & AC Villaluz - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1976 - The Japanese Society of Scientific Fisheries
      Six zoeal stages of Charybdis cruciata (Herbst) which are reared in the laboratory, are described. The zoea has a rostral, a dorsal and a pair of laterial spines. There are a pair of lateral hooks on the 2nd and 3rd abdominal segments. The number of natatory hairs on the rirst and second maxillipeds increased by one pair at each molt, being 4, 6, 8, 10, 12 and 14, in the 1st to 6th zoea, respectively. The number of inner setae on the telson are 3+3 in stage 1; 4+4 in stages 2 and 3, 4+1+4 in stage 4, and 5+5 in stages 5 and 6. Spinal arrangement form proximal to distal segment of the endopodite of the first maxillipeds are 2-2-0-2-5 in stages 1-3 and 2-2-1-2-6 in stages 4-6 and that of the second maxillipeds are 1-1-4 in stages 1 and 2 and 1-1-5 in stages 3-6.
    • Article

      The larval stages of benizuwai-gani, Chinoecetes japonicus Rathbun reared in the laboratory 

      H Motoh - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1976 - The Japanese Society of Fisheries Science
      This study deals with the larval stages of C. japonicus, and with the comparison with those of Zuwaigani, C. opilio. There are 2 zoneae and 1 megalopa. The larval stages of C. japonicus are morphologically similar to those of C. opilio excepting some characters as follows: (1) Chromatophores of Zoeae and megalopa are vermillion or crimson in C. japonicus and brown or reddish in C. opilio. (2) C. japonicus is generally bigger than C. opilio in zoeae and megalopa. (3) Length of postero-lateral spine on 3rd abdominal segment is>1.3times the length of the 4th abdominal segment in C. japonicus, but is shorter than (rarely equal to) that in C. opilio. (4) Ischiopodite of cheliped has no spine in C. japonicus, but it has a spine in C. opilio, in megalopa.
    • Conference paper

      Preliminary observation on the number of vertebra in milkfish, Chanos chanos (Forskal) 

      T Senta & S Kumagai - In Proceedings of the International Milkfish Workshop Conference, May 19-22, 1976, Tigbauan, Iloilo, Philippines, 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The existence of races and/or subpopulation in milkfish, a widely distributed species, is suggested by many workers. Comparison of mean numbers of vertebrae is one of the useful method of distinguishing subpopulations. The present paper reports the results of preliminary studies made on the vertebral counts of milkfish fry collected from several areas. The results obtained, though not conclusive, suggest the scope for further study in the line.
    • Article

      Relationship between diet composition and growth rate of the zoeal and mysis stages of Penaeus japonicus Bate 

      CT Villegas & A Kanazawa - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Diets containing Chaetoceros gracilis plus Artemia nauplii artificially prepared diet, Diet-B, and two commercial feeds Tapes and mysid meals, were fed to larvae of P. japonicus. Highest survival rate was obtained when larvae were fed with Diet-B. The results show that the early larval stages of P. japonicus can be reared on artificially prepared diets. Since the chemical composition of the diet is known, it can be used as supplemental data for larval feeding development and nutritional requirement studies for the early larval stages of Penaeus japonicus and/or other penaeids. Information is tabulated on feeds and feeding rates used, composition of the artificial diet, fatty acid composition of lipids of the different diets, and of the sterols of the different diets.