Serum steroid hormones, reproductive and larval performance of the Asian catfish Clarias macrocephalus (Gunther) during the off- and peak reproductive seasons
MetadataShow full item record
Serum samples were taken from gravid female catfish 0 to 24 h after injection of luteinizing hormone releasing hormone analogue (LHRHa) and pimozide (PIM) to monitor the serum steroid hormone levels during the off seasons (February) and the peak of the natural breeding period (August). A parallel study was also conducted to compare egg production, fertilization, hachuring and larval rates upon yolk resorption from spawn’s of hormone-treated fish. Serum E2 levels were significantly different only with varying times after injection (PI); a marked increase occurred at 13 h, but the elevation was higher in fish induced to ovulate during the peak (16.8 ng/ml) than off season(7.7ng/ml). Hormone-treated fish showed higher serum testosterone (T) levels during the peak season (17-23 ng/ml) than those injected during the off season (10-20 ng/ml) at 4-12 h PI. Serum 17¤, 20ß-dihydroxy-4-pregnene-3-one (DHP) levels og hormone-treated fish during the off season were only about half the level (0.29 and 0.52ng/ml) of those treated with the same hormones during the peak season (0.54 and 0.9 ng/ml) at 8 and 12 h PI, respectively. Initial eggs size was larger in fish induced to spawn in August (1.54 mm) than in fish induced in February (1.49 mm). All fish ovulated when induced to spawn during the peak of the natural breeding period, but ovulation rate was only 60% when were injected during the off season. Egg production, fertilization, hatchery and survival rates were similarly much higher when gravid females were induced to spawn in August (88 eggs/g body weight, 97%, 73%, and 95%, respectively) than those spawned in February (20 eggs/g BW,36%, 20%, and 47%, respectively). Results indicate that more eggs and of better quality, higher levels of T and DHP were produced during the peak season.
Tan-Fermin, J. D., Marte, C. L., Adachi, S., & Yamauchi, K. (2001). Serum steroid hormones, reproductive and larval performance of the Asian catfish Clarias macrocephalus (Gunther) during the off- and peak reproductive seasons. In J. Y.-L. Yu (Ed.), Recent Advances in Comparative Endocrinology. Proceedings of the Fourth Congress of the Asia and Oceana Society for Comparative Endocrinology, May 14-18, 2000, Academia Sinica, Taipei, Taiwan, R.O.C. (pp. 288–297). Taipei, Taiwan, R.O.C.: Institute of Zoology, Academia Sinica.
Showing items related by title, author, creator and subject.
The effect of diet on the reproductive performance of pond-reared Penaeus monodon Fabricius broodstock Millamena, Oseni M.; Primavera, Jurgenne H.; Pudadera, Rosario A.; Caballero, Rosemarie V. (Asian Fisheries Society, 1986)Three practical diets were tested for their effects on the reproductive performance, survival and larval quality of pond-reared Penaeus monodon. Diets A, B and C were formulated to contain the same basal components but ...
Primavera, J. Honculada (Aquaculture Department, Southeast Asian Fisheries Development Center, 1988)Following a review of first maturation in Penaeus monodon , details are given of endocrine, nutritional and environmental methods of induced maturation used in aquaculture. Broodstock constitution and maintenance operations ...