Now showing items 1-3 of 3

    • Article

      Harvesting techniques for Nile tilapia fingerlings 

      NS Tabbu, RB Lacierda & RV Eguia - Fisheries Research Journal of the Philippines, 1986 - Fisheries Research Society of the Philippines
      The experiment was conducted in nine-320m2 - freshwater ponds to evaluate various techniques of harvesting tilapia fry. Three treatments with three replicates each were used: harvesting by seining the fry (Treatment I), daily harvesting of fry in ponds using fine-mesh scoop net (Treatment II) and harvesting of fry from hapa net cages installed in ponds (Treatment III). All broodstock ponds were prepared, maintained uniformly and sustained through fertilization at recommended dose.

      Results of the two trials/experiments indicated that the recovery of fry in hapa net installed in ponds is far superior than the other two techniques but mortality in all treatments is not significant.

      Hapa cages are used here as a tool for easy management as well as mechanical aid to prevent predation of fry and cannibalism inherent if fish is directly stocked in ponds. Hapa also served as substrate for natural food and additional grazing areas for young tilapia fry which resulted in high recovery.
    • 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

      A practical method of extracting mimosine from ipil-ipil, Leucaena leucocephala, leaves and its effect on survival and growth of Penaeus monodon juveniles 

      VD Peñaflorida, FP Pascual & NS Tabbu - The Israeli Journal of Aquaculture-Bamidgeh, 1992 - Society of Israeli Aquaculture and Marine Biotechnology
      Soaking fresh ipil-ipil, Leucaena leucocephala, leaves in tap water (1:1, v/v; or 50 g in 500 ml) for 30-48 hours with a water change after 24 hours extract atleast 90% of its mimosine, a toxic lysine derivative. This extraction procedure is more economical and practical for fish farmers than the use of dry or moist heat or iron compounds.

      Soaked or unsoaked leaves of Peruvian or Hawaiian ipil-ipil Leucaena leucocephala formed 1/3 of trial diets fed to Penaeus monodon juveniles (1-2 g). Other protein sources consisted of fish and shrimp-head meals. A diet without ipil-ipil leaves (FS) served as the control.

      After 8 weeks, the mass weight of shrimp fed the FS and soaked Hawaiian leaf diets (HLS) was significantly (α= 0.05) higher than soaked (PLS) and unsoaked (PLU) Peruvian leaves. The HLS group had a significantly higher survival rate than the PLS and PLU groups but not the FS-fed shrimps; survival among shrimp fed unsoaked Hawaiian leaves (HLU) was zero.

      It was found that the Hawaiian variety of ipil-ipil leaves when soaked for 24 hours can be incorporated in the P. monodon juvenile diet with good survival (87%) under laboratory conditions. However, the optimum amount of leaves to be included in a low cost and efficient diet has yet to be determined.