EFFECT OF IlAYI,USCIDE ON GUOWTlI AND METAIJOLIC ACTIVITIES OF SOME FRESHWATER PHYTOPLANKTERS

EFFECT OF IlAYI,USCIDE ON GUOWTlI AND METAIJOLIC
ACTIVITIES OF SOME FRESHWATER PHYTOPLANKTERS
EZZAT A. IOR/\HlM
National Institute of Oceanography and Fisheries, Aquatic Plants Lab.,
Zarnalek Research Station, Cairo, Egypt.
A8STRACT
The present study entails effect of the conrnonly
used mollusclclde Baylusclde on growth and
biochemical constituents of the fr~shwater
chlorophytes Scenede~s df.urphus (Trup.) Kuetzlng,
Scenedesmus quadrfcauda (Trup.) de Breblsson and
Ankistrode5llllJs falcatus (Corda) Ralfs. Although
the three test algae are phylogenltlcally close,
they varied greatly in their responses to Bayluscide.
The ECSO values of Bayluscide for inhibition the
growth were: 270, 355 and 250 ppb for S. df.urphus;
175, 125 and 168 ppb for S. quadrfcaucla; and 176,
190 and 165 ppb for A. falcatus after 48, 72 and
96 h expo~vre. respectively. The chlorophrll a,
b, car’otenQld, carbohydrate and protein contents
of S. quildrfcauda and A. fl!Ilcatus s1fghtly incI”eased
when tpeated with low doses of Bayluscfde; a
phenomenon that was reversed at high doses. The
growth and chemical constituents of S. df~rphus
cells decreased with Increasing Baylusclde
concentrations.