Now showing items 47-66 of 125

    • Article

      Feeding behavior and food preference of Penaeus monodon Fabricius with scrap tilapia 

      FD Apud, N Deatras & K Gonzales - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The time of day during which P. monodon feeds at different depth levels in earthen ponds, and its preference for three types of tilapia feeds (dry, fresh and fermented) were determined. It was observed that P. monodon concentrated at the bottom beds during the day and along the periphery of dikes during night-time, with a slight tendency to swim and feed towards the surface as darkness increased. P. monodon showed special preference for dried tilapia compared to fresh and fermented tilapia. P. monodon also showed adaptability to the platform method of feeding, especially during night-time.
    • Article

      Ferrocement buoys for mussel culture 

      RT Tolosa - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A method is described for culturing mussels (Mytilus smaragdinus) using ferro-cement buoys, which may be used in the construction of a raft house or a flotation system for nets and cages.
    • Article

      Fishwater and agar as binders in a prawn diet 

      FP Pascual & N Tabbu - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The objectives of the study were to find out the proportion of water to fish fins, skin and bones that would give a good gel and to determine the effect of a combination of fish water and commercial crude agar on the water stability of the prawn diet. Under the conditions of the experiments it was concluded: (1) Fish water and commercial agar or agar bar gave the most stable pellet, 65% water stability; (2) a strong gel is obtained when one part shark fin is boiled in 1.5 parts water; (3) more fish water can be obtained from guitar fish than from shark fish.
    • Article

      The food and feeding habit of Penaeus monodon Fabricius collected from Makato River, Aklan, Philippines 

      CL Marte - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The food of Penaeus monodon collected from Makato R., from Sept 1977 to Jan 1978 is described with preliminary observations on its feeding habit and rate of foregut clearance. Feeding behaviour appears to be associated with the tidal phase. Foregut clearance rate is rapid, with 95% of food transported from the foregut 4 h after feeding. Frequency of occurrence and proportion of total food of various foregut contents are shown, as are dry weight, percentage mineral, organic and crude protein nitrogen from individual and pooled samples of gut contents, and foregut index in P. monodon collected during different phases of one tidal cycle.
    • Article

      Fry to fingerling production of Tilapia nilotica in aquaria using phytoplankton as natural feed 

      J Pantastico, C Espegadera & D Reyes - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Overall results of the study indicate that the availability of high concentrations of phyloplankton in the rearing medium favoured growth of T. nilotica fry to fingerling.
    • Article

      Fundamental study on the behavior of milkfish fry for the evaluation of the efficiency of traditional fry collecting gears in the Philippines 

      G Kawamura, S Hara & T Bagarinao - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The response of Chanos chanos fry to moving and stationary nets of different mesh size and colour, underwater visibility of the nets and water filtration were studied. Results indicate that milkfish fry may be driven by nets of mesh size larger than that presently used; larger mesh size decreases the net resistance in the water so that collectors may move the equipment easily. The large mesh nets should be of a dark colour, preferably black for effective driving; bowever white mosquito net is best for the core end, since the fry are more easily visible on a white background.
    • Article

      Gill lesions associated with acute exposure to ammonia 

      ER Cruz & GL Enriquez - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Histopathological effects of ammonia on the gills of milkfish (Chanos chanos) fingerlings were examined qualitatively.
    • Article

      Growth and survival of Penaeus monodon Fabricius zoeae on different diatom feeds 

      FP Suñaz - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A study was undertaken to determine the most suitable food for Penaeus monodon zoea out of mixed diatoms, Skeletonema costatum, Chaetoceros calcitrans and C. gracilis. Results indicate that mixed diatoms and C. gracilis are the better food. Addition of zooplankton, e.g.rotifers, is also recommended as early as Z3 since the larvae start to be omnivorous at this stage.
    • Article

      Growth and survival of Penaeus monodon postlarvae fed shrimp head meal and fish meal as primary animal source of protein 

      F Piedad-Pascual & WH Destajo - SEAFDEC Aquaculture Department Quarterly Research Report, 1978 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Although shrimp head meal alone does not provide for good growth and survival, fish meal can provide high survival rate. The addition of shrimp head improves this diet. It is suggested that cholesterol present in shrimp could have caused this difference. Composition of the test diets is tabulated, as are proximate chemical analysis of the diets, and the mean initial weights, final weights, weight gains, survival rate, feed consumed, protein consumed, of Penaeus monodon postlarvae, feed conversion and protein efficiency ratio.
    • Article

      Growth and survival rates of hatchery-produced and wild milkfish fry grown to fingerling size in earthen nursery ponds 

      DD Baliao, EM Rodriguez & DD Gerochi - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Growth and survival rates of hatchery-produced and wild milkfish (Chanos chanos) fry grown to fingerling size were compared. Data show no significant difference between the 2 fry. At a recommended stocking density of 30 fry/m2, hatchery-produced milkfish fry could attain fingerling size of almost 2g with a survival of 68%. The study indicates that hatchery-produced fry/fingerlings can equal the culture performance of the wild fry. Comparative performance of hatchery-bred and wild fry should encourage intensified research on milkfish broodstock development and refinement of induced spawning methods.
    • Article

      Growth phases of cultured algae used as larval food 

      E Jereos-Aujero - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A study was undertaken to determine the onset and duration of the growth phases of cultured algae commonly used as larval food (Skeletonema costatum, Chaetoceros calcitrans, Tetraselmis chuii, Chlorella vulgaris, Isochrysis galbana) so as to predict the time of harvest at the desired stage to suit various needs and purposes.
    • Article

      Gum arabic, carrageenan of various types and sago palm starch as binders in prawn diets 

      FP Pascual & A Sumalangcay - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An experiment was undertaken in order to investigate the use of sago palm starch, gum arabic and carrageenans as binders in prawn diets. Water stability data are presented; EPT-2 carrageenan was found to be the best binder for both steamed and unsteamed pellets.
    • Article

      Identification and culture of common diatoms as possible feed for Penaeus monodon 

      T Pimoljinda - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Diatoms were collected from Buyuan Bay, and from the hatchery tanks at Tigbauan, to determine the commonly occurring species, the feasibility of culturing these species, and the potential of these selected species as food for larval P. monodon. The commonly occurring diatoms were identified as Chaetoceros calcitrans, Navicula grimmei, Nitzchia seriata, Nitzchia closterium and Amphiprora sp. These diatoms were isolated and unialgal cultures prepared. Protein content analysis using the micro-Kjildahl method gave the following result: C. calcitrans, 11 . 78%; Nitzchia seriata, 25%; Nitzchia closterium, 30 . 5%; Navicula grimmei, 9 . 06% and Amphiprora sp. 8 . 96%.

      Feeding experiments were conducted to determine acceptability of the different diatom species and percentage survival of larval stages Z1 - M2. Larvae were placed in 4-l capacity plastic containers with a stocking density of 10/l. The results of several feeding trials using the different mass-produced diatoms are summarized.

      From the data gathered, C. calcitrans appears to be the most promising candidate as feed for zoea and mysis stages of P. monodon. The average percentage survival of C. calcitrans was 63 . 76% for the 3 trials, and as high as 82 . 22% in the third trial. Comparatively high percentage survival of larvae was also recorded when Nitzchia seriata (48 . 17%) and Nitzchia closterium (67 . 6%) were given as feed, while both Amphiprora sp. and Navicula grimmei gave 0% survival. The poor results with Amphiprora sp. and Navicula grimmei may be due to their low protein content (8 . 96% and 9 . 06%, respectively) and the inability of the larvae to ingest them. Navicula and Amphiprora were observed to cling to the appendages of the larvae and to settle down in the medium making them unavailable to the larvae. Low survival was also noted when frozen C. calcitrans was used (14 . 25%). This may be due partly to the effect of the floculating agent (ALSO4.25 g/l) used in concentrating the diatoms.

      When protein contents of C. calcitrans, N. seriata and N. closterium are compared, the 2 Nitzchia species have relatively higher protein contents than C. calcitrans and, therefore, could be the more desirable feed candidates. However, few feeding trials were made using Nitzchia so that additional investigations will have to be done on this aspect.
    • Article

      Identification of the postlarval Penaeus (Crustacea, Decapoda, Penaeidae) appearing along shore waters 

      H Motoh & P Buri - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Diagnostic characters for the identification of postlarval Penaeus appearing along the coastal waters of the Philippines are reviewed and categorized, based on materials from the wild and laboratory. Presently there are 7 adult known species belonging to the genus Penaeus around Panay Island and its adjacent waters, namely: P. monodon, P. semisulcatus, P. merguiensis, P. indicus, P. japonicus , P. canaliculatus, and P. latisulcatus.
    • Article

      Improvement of diet attractability for Penaeus monodon by supplementing various attractants 

      T Murai, A Sumalangkay & FP Pascual - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An experiment was undertaken to test the effect of supplemental krill meal, earthworm meal, glycine, sucrose or mussel water on diet attractibility of Penaeus monodon. Only glycine or mussel water significantly improved diet attractibility.
    • Article

      In vitro effects of fungicides on the fungus Haliphthoros philippinensis 

      GD Lio-Po, MCL Baticados, CR Lavilla & MEG Sanvictores - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Pure cultures of Haliphthoros philippinensis, isolated from infected Penaeus monodon larvae, were exposed for 24 hours to varying concentrations of antifungal agents. The efficiency of each agent to inhibit sporulation and mycelial growth was measured. Effects on P. monodon eggs and larvae were also investigated. It is concluded that preliminary bioassay of larval tolerance to the suggested effective doses should always be made prior to prophylaxix or therapeutic applications.
    • Article

      In-vitro effect of fungicides on hyphal growth and sporogenesis of Lagenidium sp. isolated from Penaeus monodon larvae and Scylla serrata eggs 

      GD Lio-Po, MEG Sanvictores, MCL Baticados & CR Lavilla - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The sensitivity of Lagenidium, isolated from Penaeus monodon, Scylla serrata , to 34 antimycotics was determined. Effects on the development of vesicles, zoospores and mycelial growth were evaluated. Although mycoidal levels of the chemicals tested will be ideal for lethal treatment on control of the fungus, the high dose required may be lethal to the host, thus the use of mycostatic concentrations is more practical. Treatments of rearing water containing larvae, adult shrimps or crabs should be done only after preliminary tolerance experiments using at least the mycostatic dose prove to be safe for the hosts. Mycocidal doses can be used for determining disinfection doses of equipment and facilities used in rearing procedures as well as for destroying batches of infected larvae.
    • Article

      Ipil-ipil (Leucaena leucocephala) leaves as a plant protein source in prawn diets 

      F Piedad-Pascual & NS Tabbu - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Penaeus monodon juveniles were fed diets containing fish meal, shrimp head meal and ipil-ipil leaves soaked and unsoaked, local and peruvian varieties. Mean weight gain at the end of 8 wk was significantly highest among those given the diet containing commercial ipil-ipil leaves. Gain in length followed the same pattern as mean weight gains. Among the diets containing ipil-ipil leaves there was a direct relationship in the amount of mimosine in the diet and the survival rate, the lower the amount of mimosine (due to soaking) the higher the survival rate. The Results thus indicate the beneficial effect of the addition of commercial ipil-ipil leaves to the diets of prawns, providing the mimosine content is kept low by soaking. A reduce in costs is also obtained, since 1kg of shrimp head meal or fish costs more than 2 or 4 tons, respectively, than that of ipil-ipil foliage.
    • 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.