Collected reprints: Abstract 3209

Collected reprints

Abstract

Van Beek, E.; Criel, G.; Walgraeve, H.; De Loof, A. (1987). Moulting-hormone activity in adult Artemia. Artemia Research and its Applications 2: 173-179

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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