Now showing items 1-11 of 11

    • Conference paper

      Cannibalism among different sizes of tilapia (Oreochromis niloticus) fry/fingerlings and the effect of natural food 

      JB Pantastico, MMA Dangilan & RV Eguia - In RSV Pullin, T Bhukaswan, K Tonguthai & JL Maclean (Eds.), The Second International Symposium on Tilapia in Aquaculture, 1988 - Department of Fisheries, Bangkok, Thailand; International Center for Living Aquatic Resources Management, Manila, Philippines
      Experiments were conducted in jars, tanks and aquaria to determine the occurrence of cannibalism among 7 different size groups of Nile tilapia (Oreochromis niloticus ) fry and fingerlings. Cannibalism became more intense as the size difference increased. Big fry were less susceptible to cannabalism than small fry. On the other hand, bigger fingerlings were highly cannabalistic compared with smaller ones. This was evident as early as the first 10 minutes after stocking when fingerlings which usually stayed at the bottom moved swiftly towards the surface and swallowed the smaller fry.

      Availability of additional natural food in the growing medium affected survival of fry (mean weight = 9.3 mg) which were stocked with fingerlings (mean weight = 163.5 mg) in aquaria. Feeding with Spirulina proved more effective in reducing cannibalism than feeding with Navicula . After 5 days of rearing, fry survival was highest when fed with Spirulina (83.1%) followed by Navicula (16.6%) and the unfed control (5.6%).
    • Article

      Growth response of Nile tilapia fry to salinity stress in the presence of an ‘internal reference’ fish 

      ZU Basiao, RV Eguia & RW Doyle - Aquaculture Research, 2005 - Blackwell Publishing
      Growth of three strains of Oreochromis niloticus L. fry exposed to salinity stress in the presence of an internal reference fish were compared. The Central Luzon State University (CLSU) strain was obtained from the Freshwater Aquaculture Center, CLSU, Philippines. The ISRAEL strain was acquired from the Philippine government's Bureau of Fisheries and Aquatic Resources National Freshwater Fisheries Technology Center (BFAR-NFFTC), Munoz, Nueva Ecija. The National Inland Fisheries Institute (NIFI) strain was obtained from the NIFI, Bangkok, Thailand. Eight to nine full-sib families (replicates) per strain were split into two groups. One group was grown in freshwater for 2 weeks, acclimated to 32 ppt and reared for 2 weeks and finally grown in freshwater for another 2 weeks. Another group was contemporaneously grown in freshwater polyethylene tanks for 6 weeks. Each replicate family included a size-matched internal reference population of red tilapia strain. Two-way analysis of variance (anova) revealed no significant strain differences (P=0.081; r2=0.106). However, analysis of covariance with the internal reference strain used as a covariate showed significant (P=0.049; r2=0.638) strain effects on specific growth (based on standard length measurements). The ISRAEL strain showed consistently better growth rate in both saline and freshwater environments than the NIFI and CLSU strains. We estimated the statistical power of the two-way anova (ϕ=√(k′−1)(factor MS−s2)/(k′s>2); Zar 1984) to be ∼0.30. There was a 70% probability of a Type II error and no true difference in the growth of the three strains was detected. The use of internal reference strain as a covariate improved the r2 from 0.106 to 0.638 and increased the efficiency of the test in detecting a true difference. Other strain comparison studies in our laboratory at the Southeast Asian Fisheries Development Center Aquaculture Department showed that the ISRAEL strain shows better growth than the NIFI and CLSU strains in a crowding stress tolerance experiment, when fed only with rice bran and under restrictive feeding regimes.
    • Article

      Growth response of three Oreochromis niloticus strains to feed restriction 

      MRR Eguia & RV Eguia - The Israeli Journal of Aquaculture-Bamidgeh, 1993 - Society of Israeli Aquaculture and Marine Biotechnology
      Growth of fry from three test strains of Nile tilapia (CLSU, ISRAEL and NIFI) fed restrictively and nonrestrictively were compared. Four-week old fry were matched for size with similarly aged red tilapia fry which served as an internal reference. Fish were stocked in 60l aquaria at a ratio of 25 tests:25 reference fish. Test fish were fed commercial fish feed ad libitum during the initial and final two weeks and rations of the same feed at 10% of the fish biomass during weeks 3 and 4. Control fish were fed commercial fish feed ad libitum throughout the six week experiment. Although feed restriction retarded growth in all three test strains, growth differed significantly between strains. Under both restrictive and nonrestrictive feeding regimes, the ISRAEL strain grew better than the CLSU and NIFI strains.
    • 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.
    • Book

      Modyular na pag-aalaga ng tilapya sa mga kulungang lambat 

      RV Eguia, MRR Romana-Eguia & ND Salayo - 2011 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 51
      An extension manual detailing traditional cage culture method, concept of modular cage culture, economic feasibility of modular cage culture, and post harvest processing.
    • Book

      Pag-aalaga ng tilapya 

      RV Eguia & MRR Eguia - 2007 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 22
      The manual discusses tilapia culture methods in concrete tanks, netcages, and fishponds. It details the species of tilapia cultured in the Philippines, which include Oreochromis nilotucus, O.mossambicus, O.aureus. It covers the following: site selection; construction of netcages and its modules; fishpond construction and pond preparation; criteria for fry selection; stocking; netcage and pond management including water quality management; and harvest. The manual also lists the agencies involved in tilapia research and development in the Philippines; defines some technical terms in a glossary, and lists some useful references.
    • Book

      Pagpapaanak ng tilapya 

      RV Eguia & MRR Eguia - 2007 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 23
      This 52-page revised edition of the 1996 manual, discusses the spawning of tilapia in concrete tank hatcheries, hapa hatcheries in ponds and lakes and the hatchery operations of tilapia.
    • Book

      Pagpapaanak o pagpaparami ng tilapya 

      RV Eguia, MRR Eguia & ZU Basiao - 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 23
      The manual discusses spawning tilapia (Oreochromis spp) in concrete tank hatcheries, hapa hatcheries in ponds and in lakes in the Philippines. Also included in the manual are a list of agencies involved in tilapia research, a glossary of technical terms, and useful references.
    • Conference paper

      Salt tolerant Nile tilapia production: Prospects in aquaculture 

      RV Eguia & MRR Romana-Eguia - In MC Remany & J Kumar (Eds.), Proceedings of the India Tilapia Summit 2014 and 2nd Edition of the Dr. E. G. Silas Endowment Lecture, 18th December 2014, Vijayawada, India, 2016 - Rajiv Gandhi Centre for Aquaculture (MPEDA)
      In the Philippines, salt tolerant Nile tilapia strains have been developed and promoted for culture to increase tilapia production in brackishwater pond systems previously dedicated for milkfish and/or penaeid shrimp culture. This was mainly done to address the decline in the production of such major commodities in ponds and/or cages brought about by diseases and mass fish kills caused by intensified culture methods. The present paper focuses on the different salt tolerant Nile tilapia stocks that have been developed and disseminated in the Philippines, the culture practices involved, as well as the prospects for profitable production of Nile tilapia in saline conditions.
    • Book

      Tilapia broodstock and hatchery management 

      RV Eguia & MRR Eguia - 2007 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 38
      This manual will surely assist tilapia operators and technicians in producing good-quality fry and fingerlings which the industry currently needs. Fisheries researchers, teachers, and students will also find this manual as a good source of basic informarion regarding tilapia broodstock and hatchery management.
    • Book

      Tilapia farming in cages and ponds 

      RV Eguia & MRR Romana-Eguia - 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 36
      This 40-page manual describes the farming practices for tilapia in cages, pens, ponds, and tanks. Also details selection of quality seedstock, maintenance of stock (feeding, water management), and harvesting. A list of institutions working on tilapia R&D is included.