Now showing items 1-3 of 3

    • Conference paper

      Effects of single injection of carp pituitary extract and human chorionic gonadotropin on germinal vesicle migration and ovulation in lampan sungai, Puntius schwanenfeldii (Bleeker): A preliminary study 

      SA Harmin, R Joannes & SH Cheah - 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 effects of crude pituitary extract (CPE) and human chorionic gonadotropin (hCG) on germinal vesicle migration and ovulation in lampan sungai Puntius schwanenfeldii (Bleeker) were investigated. Sexually mature female lampan sungai were divided into four groups (n=3 per group). In both experiments, fish were injected intramuscularly (im) once and were checked for germinal vesicle migration and sign of ovulation 8 h following injection. In experiment 1, females were treated with CPE at doses of 2, 4, or 6 mg/kg body weight (BW) while controls were administered an equivalent volume of saline. Ovulation occurred in one fish given 2 mg/kg and in another fish that received 6 mg/kg CPE. In a second experiment, female fish were administered hCG at doses of 1000, 2000, or 4000 IU/kg body weight. Similarly, controls received only saline. One female injected with 4000 IU/kg hCG responded positively to the hormone treatment. Clearly, in our study, a single intramuscular injection of CPE and hCG induced spawning in lampan sungai as well as accelerated oocyte development as evidenced by the increasing percentage of oocytes showing germinal vesicle migration.
    • Conference paper

      Endocrine changes associated with overripening of ovulated eggs in goldfish, Carassius auratus L. 

      MJ Formacion & TJ Lam - 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
      Changes in steroid hormone levels in the serum and ovarian fluid were studied during overripening in goldfish. Ovulated eggs retained in the ovarian cavity become overripe at around 12 h after ovulation and completely overripe 24 h after. Blood and ovarian fluid were taken at 0, 3, 6, 12, 18, and 24 h after ovulation. Estradiol-17ß (E 2) , testosterone (T), progesterone (P) and 17α,20ß-dihydroxy-4-pregnen-3-one (17α,20ß-P) in the serum were extracted directly with a solvent while those in the ovarian fluid were separated by HPLC before radioimmunoassay. Both serum and ovarian fluid P showed a highly significant decline at 18 h with a further decline at 24 h; P levels were higher in the ovarian fluid. Serum 17α,20ß-P showed a progressive and more rapid decline, decreasing significantly at 12 h with further decreases at 18 h and 24 h; the level was five-fold lower at 24 h compared to the 0 h level. Serum T increased significantly at 3 h which was maintained until 18 h, when it declined to 0 h level. No significant changes in E2 were observed in the serum, except for a significant difference between 6 and 24 h. There were no significant changes in E2, T and 17α,20ß-P in the ovarian fluid. Of the four steroids measured, only 17α,20ß-P and P showed changes which bear some correlation with the time course of overripening. The declines in the mean ratios of 17α,20ß-P/E2 in the serum and P/E2 in the ovarian fluid also appeared to have a good correlation with the time course of overripening. The postovulatory follicles (POFs) showed degenerative features which likewise correspond to the decline in P and 17α,20ß-P.
    • 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.