Coupling effects of hydrodynamics and predatory activity of Nepthys homberg
ii (Savigny) (Polychaeta: Nephtyidae) on emigration of Hediste diversicolor
(O.F Muller) (Polychaeta: Nereidae) recruits were assessed in a flume. Exp
eriments carried out in still water conditions and in the flume flow showed
that predatory activity of N. hombergii is independent of the presence or
the absence of flow and does not statistically influence the recruit emigra
tion rate. It appears, however, that hydrodynamics is an inhibiting factor
for the emigration of H. diversicolor which occurs in the absence of flow.
The comparison of these results with literature data suggests that recruits
could use hydrodynamics to leave an unsuitable habitat according to the sp
ecies mobility range. (C) 2000 Academie des sciences/Editions scientifiques
et medicales Elsevier SAS.