Breeding and Seed Production of Cultured Finfishes in the Philippineshttp://hdl.handle.net/20.500.12066/51012024-03-28T11:19:54Z2024-03-28T11:19:54ZEndocrine changes associated with overripening of ovulated eggs in goldfish, Carassius auratus L.Formacion, Minda J.Lam, Tom J.http://hdl.handle.net/20.500.12066/51292022-02-28T03:24:40Z1996-01-01T00:00:00ZEndocrine changes associated with overripening of ovulated eggs in goldfish, Carassius auratus L.
Formacion, Minda J.; Lam, Tom J.
Marte, Clarissa L.; Quinitio, Gerald F.; Emata, Arnil C.
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.
1996-01-01T00:00:00ZThe role of cyclic amp in oocyte maturation of goldfish, Carassius auratusSeraspe, Ebonia B.Tan, Cheong HuatLam, Tom J.http://hdl.handle.net/20.500.12066/51302022-02-28T03:21:34Z1996-01-01T00:00:00ZThe role of cyclic amp in oocyte maturation of goldfish, Carassius auratus
Seraspe, Ebonia B.; Tan, Cheong Huat; Lam, Tom J.
Marte, Clarissa L.; Quinitio, Gerald F.; Emata, Arnil C.
The role of cyclic AMP in oocyte maturation was investigated using denuded goldfish oocytes cultured in vitro. The oocytes were stimulated with a maturation-inducing steroid (MIS), 17α, 20ß dihydroxy-4-pregnen-3-one (17, 20 P) with or without forskolin or forskolin only. Changes in cAMP concentrations and percent maturation of the oocytes were determined. Results showed that elevated levels of cAMP maintain the oocytes in meiotic arrest while a decrease would trigger the resumption of meiotic maturation.
1996-01-01T00:00:00ZMaturation of Oreochromis niloticus gonadsCasauay, A. A.Carino, V. S.http://hdl.handle.net/20.500.12066/51312022-02-28T03:24:50Z1996-01-01T00:00:00ZMaturation of Oreochromis niloticus gonads
Casauay, A. A.; Carino, V. S.
Marte, Clarissa L.; Quinitio, Gerald F.; Emata, Arnil C.
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.
Abstract only.
1996-01-01T00:00:00ZInduced spawning of the mangrove red snapper, Lutjanus argentimaculatusEmata, Arnil C.Eullaran, B.de los Santos, M.http://hdl.handle.net/20.500.12066/51322022-02-28T03:21:20Z1996-01-01T00:00:00ZInduced spawning of the mangrove red snapper, Lutjanus argentimaculatus
Emata, Arnil C.; Eullaran, B.; de los Santos, M.
Marte, Clarissa L.; Quinitio, Gerald F.; Emata, Arnil C.
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.
Abstract only.
1996-01-01T00:00:00Z