Now showing items 1-4 of 4

    • Article

      Developmental and ecological stages in the life history of milkfish Chanos chanos (F.) 

      P Buri, VC Bañada & AT Triño - Fisheries Research Journal of the Philippines, 1981 - Fisheries Research Society of the Philippines
      Seven stages in the life history of milkfish Chanos chanos are suggested: embryonic, yolksac larval, larval, postlarval, juvenile, sub-adult and adult stages. These were based on morphological differences and on their particular ecological requirements. The latter include: behavioral pattern, food and feeding habits, and habitat requirements. Throughout the life cycle of milkfish the stronger driving force with determines particular behavioral strategies can be attributed to the evolutionary response of the organism of food distribution (availability) followed by predation pressure.
    • Article

      Economic evaluation of grow-out diets for Asian catfish Clarias macrocephalus (Gunther) production 

      EB Coniza, JD Tan-Fermin, MR Catacutan, AT Triño & RF Agbayani - UPV Journal of Natural Sciences, 2000 - University of the Philippines in the Visayas
      The economic feasibility of four grow-out diets for the Asian catfish Clarias macrocephalus was evaluated on a 1000 m2/crop basis. Hatchery-bred catfish juveniles with mean body weight (MBW) of 3.6 g and mean total length (MTL) of 7.8 cm were stocked at 10 fish/m2. Laboratory-formulated diet with 20% crude protein (CP; Diet 1) resulted in net losses. Laboratory-formulated diet with 34% CP (Diet 2), commercial feed pellet with 29% CP (Diet 3), and a mixed diet of blanched chicken entrails (80%) and rice bran (20%) with 32% CP (Diet 4) gave acceptable return on investment (ROI) of 131-326% and return on operating capital of 52-71%. Culture of Asian catfish fed Diet 2, however, attained higher net profit before tax per 1000 m2/crop, ROI (326%), and has the lowest payback period on investment (0.3 yr) or operating capital (1.4 yr) compared with using Diets 3 and 4. Partial budget analysis showed that higher net benefit can be earned by using Diet 2 as feed for C. macrocephalus compared with using Diet 4. Sensitivity analysis done by increasing in feed cost by 20% and decreasing the selling price of fish by 20% showed that ROI were 107-262% and 46-159%, respectively and return on operating capital of 42-57% and 18-35%, respectively. Payback period on investment were 0.4-0.9 yr and 0.6-1.9 yr, respectively while payback period on operating capital were 1.7-2.2 yr and 2.7-4.7 yr, respectively. Results suggest that C. macrocephalus culture is economically feasible with Diets 2, 3 and 4 as feed but the use of Diet 2 is more profitable.
    • Article

      Growth and survival of Penaeus monodon juveniles fed a diet lacking vitamin supplements in a modified extensive culture system 

      AT Triño, VD Peñaflorida & EC Bolivar - Aquaculture, 1992 - Elsevier
      Penaeus monodon juveniles with mean initial weight from 0.11 to 0.17 g were fed diets with and without vitamin supplement. The diets contained 34% protein and 8% fat. The animals were stocked at 5/m2 in 320-m2 earthen ponds and reared for 135 days. Growth, survival, net production, and net cost of production per kg of P. monodon were not significantly affected even if supplemental vitamins were eliminated from the diet. The absence of extra vitamins from the diet may have been compensated either by the basal diet used or by ingestion of natural food existing in the ponds. In either case, the possible influence of vitamins from these sources is manifested in the overall effects on growth, survival and net production of prawns when no vitamin supplement is added to the diet. Results obtained showed that the difference between diets in cost of production was statistically not significant (P > 0.05). However, the favorable cost difference of P 18.02 per kg of prawns produced would make it more profitable to use the diet without vitamin supplement in a modified extensive culture system.
    • Article

      Growth performance of Penaeus monodon in lablab, lumut, and digman ponds under various farm practices 

      AT Triño & MEC Bolivar - Journal of Aquaculture in the Tropics, 1990 - Taylor & Francis
      The influence of lablab, lumut (filamentous algae), and digmaan (Najas graminea) on the growth of prawns as associates of natural food biomass in brackishwater ponds was investigated. Ponds, each grown with the above macrophytes species and with no supplementary feed used, were selected as sampling areas. Sampling was conducted on a biweekly basis. Results showed that although the specific growth rate of prawns reared in the lablab pond was significantly higher than that of prawns reared in the lumut and digman ponds (p<0.01), absolute values in growth showed otherwise. Prawns reared in the digman pond attained highest growth which was significant (p<0.01). The digman pond was able to support a much higher density and produce a higher growth, coupled with a substantial survival. The digman pond yielded 606 kg of prawns, while the lablab pond yielded 569.5 kg and the lumut pond 305 kg. At value of $ 10 per kg, the rearing of prawns in the digman pond would be more profitable than the other treatments.