Moulting-hormone activity in adult Artemia
Van Beek, E.; Criel, G.R.J.; Walgraeve, H.; De Loof, A. (1987). Moulting-hormone activity in adult Artemia, in: Decleir, W. et al. Artemia research and its applications: 2. Physiology, biochemistry, molecular biology. Proceedings of the Second International Symposium on the brine shrimp Artemia. pp. 173-179 In: Decleir, W. et al. (1987). Artemia research and its applications: 2. Physiology, biochemistry, molecular biology. Proceedings of the Second International Symposium on the brine shrimp Artemia. Universa Press: Wetteren. 562 pp., more |
| Available in | Authors | | Document type: Conference paper
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| Keywords | Biological phenomena > Metamorphosis > Moulting
Secretory products > Hormones
Artemia Leach, 1819 [WoRMS]
Marine/Coastal |
| Authors | | Top | - Van Beek, E.
- Criel, G.R.J., more
- Walgraeve, H.
- De Loof, A.
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| Abstract | The Artemia strain from Great Salt Lake (GSL 375) was used. Total body extracts and hemolymph of Artemia were purified by solvent partition and column chromatography. Moulting-hormone concentrations were then determined by a specific radioimmunoassay (RIA). Results are expressed in ng ecdysteroid activity/g fresh weight (or per ml). Initially, the RIA data on extracts of adults were highly variable. The use of a more accurate sampling technique based on the reproductive cycle of the females allowed to determine a hormone activity pattern.In females, moulting cycles alternate with vitellogenic cycles. The lowest values of ecdysone (3-6 ng ecdysone equivalents/g fresh body weight or ml hemolymph) occur during previtellogenesis and when lateral sacs containing ripe eggs are present. Peak values (+/- ng/g) are reached every vitellogenic cycle at periods corresponding to the most intensive yolk accumulation.The exact timing of developmental progress in the adult stage is much more difficult in males than in females. Ecdysteroid peak values (+/- 10 ng ecdysone equivalents/g fresh body weight) are present during the copulation period. |
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