Phytoplankton
inhibition of copepod egg hatching: test of an exudate hypothesis
K.W. Tang, H.G. Dam-2001
Marine Ecology Progress Series, 209: 197-202
(from Current Contents)
Abstract :
Recent papers have reported that certain marine
diatoms are deleterious to copepod egg production and hatching. Diatom
harmful effects can result from 2 different mechanisms: diet-induced
maternal effects and external effects. We conducted 5 separate egg
incubation experiments to test if phytoplankton exudates (an external
effect) were harmful to copepod eggs. Exudates produced by 3 reportedly
toxic diatoms, plus 2 non-diatom species, had no effects on egg hatching in
the copepod Acartia tonsa. Thus, phytoplankton exudates are not likely to
inhibit egg hatching. A seasonal relationship was observed between egg
production and egg hatching of A. tonsa such that high egg production rate
resulted in high egg hatching success (80 to 100%), but low egg production
rate resulted in highly variable egg hatching success (80 to 90 %).
(Univ Connecticut, Dept Marine Sci, Groton, CT 06340,
USA, e-mail of H.G. Dam: hgdam@uconn.edu)