Now showing items 1-5 of 5

    • Conference paper

      Effects of different fat sources on the egg quality of grouper, Epinephelus suillus 

      GF Quinitio, RM Coloso, A Duller & D Reyes - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The effect of different fat sources on the egg quality of grouper, Epinephelus suillus eggs was evaluated. Fish in three tanks, each containing 3 females and 1 male, were fed various types of feeds namely: trash fish (control), trash fish + cod liver oil (treatment 1) and trash fish + SELCO, a lipid emulsion containing high levels of highly unsaturated fatty acid (HUFA) (treatment 2).

      Approximately 77.9 million eggs spawned from January to October 1992 by the control group, 40.0 million by fish in treatment 1, and 36.4 million by the treatment 2 group. Egg production (0.45 million eggs/kg BW) among the control group was significantly higher than treatment 2. Egg production of treatment 1 (0.06-0.36 million eggs/kg BW) was not significantly different (P<0.01) from the control group nor treatment 2 (0.02-0.30 million eggs/kg BW). Fertilization and hatching rates showed significant differences among the three groups with control > treatment 1 > treatment 2. There were no differences detected in the egg and oil globule diameters among the treatments. Crude protein and lipid levels of floating (good) and sinking (bad) eggs collected in February to March 1992, and August to September 1992 were similar in all treatments. Unfed larvae from treatment 1 survived until the fifth day after hatching while those in the control and treatment 2 groups lasted only until the third day. These results suggest that supplementation of cod liver oil and SELCO in the trash fish diet of E. suillus broodstock does not influence egg production, fertilization and hatching rates, and egg quality.
    • Conference paper

      Induced spawning of the mangrove red snapper, Lutjanus argentimaculatus 

      AC Emata, B Eullaran & M de los Santos - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Wild-caught mangrove red snapper, Lutjanus argentimaculatus, reared for a year in 4.0 m diameter by 1.5 m deep circular concrete tank spontaneously matured and were used for induced spawning trials. On 19 August 1992, a sexually mature female (4.6 kg BW) and male (3.2 kg BW) fish were given a single intramuscular injection of 1500 IU human chorionic gonadotropin (hCG)/kg BW. Spawning occurred 27 h after injection with total egg collection of 1.3 M. Hatching occurred 16 h after spawning at 28 °C and 32 ppt. On 18 March 1993, the same male and female together with a newly-caught spermiating male (6.3 kg BW) were injected intramuscularly with 100 µg luteinizing hormone-releasing hormone analogue (LHRHa)/kg BW. Spawning occurred 44 hours after injection with the total egg collection of 0.7 M. Hatching occurred 16 hours after spawning at the same temperature and salinity as the first trial. The successful spawning trials encourage further research to determine the effective minimum dose of hCG and LHRHa.
    • Conference paper

      LHRHa and pimozide-induced breeding in the catfish, Clarias macrocephalus (Gunther) 

      JD Tan-Fermin, RSJ Gapasin, AM Tan, MA Garcia & AC Emata - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Clarias macrocephalus is endemic yet dwindling freshwater foodfish in the Philippines. Induced breeding protocol was developed by monitoring the size and maturation of eggs at 0-48 h after a simultaneous injection of luteinizing hormone-releasing hormone analogue (LHRHa; 0.0005 - 0.10 µg/g BW) and pimozide (PIM; 1 µg/g BW). Based on its similar osmotic pressure with catfish plasma, eggs were fixed in 1% phosphate-buffered formalin. Mean egg diameter of fish that were induced to mature increased during ovulation. Oocyte maturation, indicated by oocytes with germinal vesicle breakdown (GVBD), was observed at least 12 h post-injection in fish given 0.01 - 0.10 µg LHRHa + 1 µg PIM/g BW, followed by ovulation 4 h thereafter. Results showed that a simultaneous injection of C. macrocephalus with 0.05 µg LHRHa + 1 µg PIM/g BW at 1800-1900 h followed by stripping at 16-20 h post-injection resulted in high ovulation, fertilization and hatching rates.
    • Conference paper

      Maturation of Oreochromis niloticus gonads 

      AA Casauay & VS Carino - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      At hatching when fry were 5 to 6 mm, primordial germ cells (PGCs) were found to concentrate along the dorsomedian region of the peritoneal wall at the root of the developing mesentery and in places far from the appearance of testocoel and ovocoel. At 56 days posthatching, oogenic cells in the ovary had enlarged approximately 2 to 3 times their former size. The testis remained quiescent although the stromal tissues with developing efferent ducts increased distinctly in amount. Spermatogenesis occurred at three months posthatching.
    • Conference paper

      A review of grouper (Epinephelus suillus) fry production research in Malaysia 

      HM Ali - In CL Marte, GF Quinitio & AC Emata (Eds.), Proceedings of the Seminar-Workshop on Breeding and Seed Production of Cultured Finfishes in the Philippines, Tigbauan, Iloilo, Philippines, 4-5 May 1993, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Research on grouper (Epinephelus suillus) fry production in captivity has been carried out in Malaysia since 1986 at Tanjung Demong Marine Finfish Production and Research Centre (TDMFPRC) but the breakthrough was only achieved four years later in 1990. Eggs were obtained through natural and induced spawning in tanks. Natural spawning of grouper in captivity seldom occurred and was unpredictable. However induced spawnings were successfully carried out by injecting human chorionic gonadotropin (hCG) intramuscularly at a dose of 500-1000 IU/kg fish.

      The results from several trials on larval rearing conducted since 1989 until recently showed that larvae obtained from natural spawnings survived longer with some reaching the juvenile stage. The highest recorded survival rate of 43 days posthatch (32.5 mm total length) was 12.1% at 28-32 °C water temperature. On the other hand, 100% mortality usually occurred in larvae obtained from induced spawning 7 days after hatching.

      The major constraints of grouper fry production in Malaysia are lack of male spawners, inconsistent and unpredictable natural spawning, small quantity of eggs released every spawning day, poor fertilization and hatching rate, weak hatchlings, and high mortality rate at the early stages of larval development. The latter is probably due mainly to problems on initial feeding.