Now showing items 1-4 of 4

    • Conference paper

      Abalone culture: an emerging aquaculture technology 

      AC Fermin - In Fishlink 2001, 29-31 May 2001, Sarabia Manor Hotel, Iloilo City, 2001 - University of the Philippines Aquaculture Society
    • Article

      Multiple gonadal maturation and re-maturation after hormone-induced spawning in bighead carp Aristichthys nobilis Rich. 

      AC Fermin, MA Laron & DM Reyes Jr. - The Philippine Scientist, 1991 - San Carlos Publications, University of San Carlos
      Gonadal maturation and rematuration after hormone-induced spawning in cage-reared female bighead carp Aristichthys nobilis were observed. Percent maturation ranged from 54 to 100% for females and 0 to 40% for males. Maturation rates in either sex were high during March (1988) and low during December (1987). No significant differences were observed for monthly mean oocyte diameters ranging from 1.41 to 1.51 mm. Of the 34 females injected with LHRH-a, Domperidone or HCG, either singly or in combinations, 12 females spawned successfully. Three females were spawned twice consecutively at intervals between 71 and 107 days. Fish possessed oocytes of similar characteristics as those obtained from pre-spawning females when sampled after 27 days from spawning. Generally, oocyte diameters of individual fish measured before the first spawning (range: 1.41 to 1.53 mm) were not significantly different from those measured during the succeeding spawnings (range: 1.38 to 1.49 mm). Physico-chemical and biological parameters in the lake did not influence maturation except for zooplankton.
    • Article

      Nursery rearing of the Asian sea bass, Lates calcarifer, fry in illuminated floating net cages with different feeding regimes and stocking densities 

      AC Fermin, MEC Bolivar & A Gaitan - Aquatic Living Resources, 1996 - Cambridge University Press
      Successful rearing of hatchery-reared sea bass, Lates calcarifer, fry in illuminated floating cages was demonstrated in a 42-day experiment. Three feeding regimes, i.e. natural zooplankton (NZ) + minced fish flesh (MFF), NZ alone, or MFF alone and two stocking densities (600 and 1 200 individuals m2) were tested in a 3 × 2 factorial experiment. Fish reared in unlit cages and fed MFF alone during daytime served as the control. Results showed that no interaction existed between stocking density and feeding regime and that the two stocking densities used did not influence fish growth in terms of mean final body size. In general, sea bass reared in lit cages (NZ + MFF and NZ) grew and survived better than the control fish (MFF). However, fish reared under NZ + MFF feeding regime had the highest final mean total length (TL, 42.1 mm) and body weight (BW, 1 311.8 mg) followed by fish reared under NZ feeding regime (mean TL = 26 mm, BW = 415 mg). Fish in the unlit control cages exhibited the poorest growth (final mean TL and BW: 26 mm and 277.6 mg BW). Furthermore, specific growth rates (range: 5.7–8.5% day−1) of fish in lit cages were significantly better than those of fish in the unlit control cages (mean: 3% day−1). Percentage survival (38%) of fish stocked at 600 m−2 density and fed NZ was not significantly different from fish in the NZ + MFF feeding regime. However, increasing the density to 1 200 ind. m−2 tended to significantly decrease percentage survival (20%) of fish with NZ feeding. Fish reared in the unlit control cages had the poorest survival of 13–14%. The high percentage composition by number (CN, 88%) of copepods in the stomachs of sea bass fry fed on NZ alone and the equally high percentage feeding incidence (94%) indicated that fish fed sufficiently on natural zooplankton. Supplemental feed using minced fish flesh contributed about 43–59% of the fish diet in addition to natural zooplankton.
    • Conference paper

      Studies on the nursery rearing of seabass, Lates calcarifer (Bloch) fry in illuminated floating net cages 

      AC Fermin, MEC Bolivar & A Gaitan - In SA Al-Thobaiti, HM Al-Hinty, AQ Siddiqui & G Hussain (Eds.), Aquaculture Technology and Investment Opportunities. Proceedings of the First International Symposium on Aquaculture Technology and Investment Opportunities, 11-14 April 1993, Riyadh, Saudi Arabia, 1994 - Ministry of Agriculture and Water; King Abdulaziz City for Science and Technology; Riyadh Chamber of Commerce and Industry
      The feasibility of rearing seabass, Lates calcarifer, fry for fingerling production in illuminated floating nursery cages was determined. In experiment 1, seabass fry of 20.0 mm mean TL were stocked at 600 and 1200 in 1 m3 illuminated cages and reared without supplemental feeding. Control fish were stocked at same densities in non-illuminated cages and fed minced trash fish. After 42 days, fish held in illuminated cages at either density had higher specific growth rates (SGR) and percent survival (20-38%) than those of fish reared in non-illuminated cages. Mean number of zooplankton trapped inside the illuminated cages was significantly higher than those found in the non-illuminated cages which was dominated by Copepods such as the Calanoid, Cyclopoid and Harpacticoid and their nauplii. In experiment 2, minimum body size of seabass fry at stocking in illuminated cages was determined. Seabass fry of 7.35, 11.30, 18.73 and 20.71 mm total length (TL) were stocked at three replicates in illuminated cages and reared for 30 days. Percent survival was significantly higher for fish stocked at an initial size of 11.30 mm TL than the other size groups. Number of “shooters” (range = 6-9%) was significantly higher among fish with initial size of 7.35 mm and 20.71 mm than in other groups. SGR of 8.28%/day was highest for fish with mean stocking size of 7.35 mm TL. Feeding incidence (FI) ranging from 13.16 ± 6.7% to 54.9 ± 4.2% was similar for all size groups during the first week of rearing and significantly increased towards the end of rearing period except for fish stocked at 7.35 mm initial TL. Results showed that nursery rearing seabass fry in illuminated cages is feasible. Natural zooplankton were attracted into the cages by artificial illumination sufficiently served as food to fish. Minimum stocking size of seabass fry is from 10-15 mm TL for better survival. Early transfer of fry in nursery cages and availability of natural zooplankton through artificial illumination can be a cost-effective method of nursing seabass fry.