Effects of lunar cycles on Artemia
density in hypersaline environments
W.N. Camargo, L. Van Vooren, P. Sorgeloos-2002
Hydrobiologia, 468(1-3): 251-260
Abstract:
The effects of lunar cycles are known to have an
influence, although not yet clear, on the behavior of aquatic organisms. A
study was conducted in two different locations (Manaure, Guajira and
Chengue, Magdalena, Caribbean coast, Colombia) during July and August, 1997
and November, 1998 to determine the effects of medium term cycles (lunar
cycles) on the presence of Artemia franciscana (Crustacea:
Anostraca) density. Samples were collected every 4 h from each of 20 fixed
stations in a salt production pond during a 24-h sampling period at the peak
of the four lunar phases. The data were analyzed using a mixed ANOVA model,
setting lunar phases and sampling time intervals as fixed effects, station
as the random effect and density as the dependent variable. No significant
difference was determined between increasing and decreasing moon. Artemia
density was not significantly (P>0.05)
higher during new moon compared to full moon. The influence of temperature
over Artemia sampling density was clearly noticed, and was a
shading factor over the possible effects of any particular lunar phase over Artemia
density at any particular sampling time.
(Laboratory of
Aquaculture &
Artemia Reference Center, Ghent University, Rozier 44, B-9000, Ghent,
Belgium, e-mail: wcamargo@hotmail.com)