Ciguatoxin reduces larval survivability in finfish

Ciguatoxins are lipophilic polyether toxins which concentrate in the viscer a and flesh of coral reef associated finfish (Hessel et al., 1960). In this study, we quantify the adverse effects of ciguatoxin on fish embryos by mi croinjection into the egg yolk of medaka (Oryzias latipis) embryos. Embryos microinjected with 0.1-0.9 pg/egg (ppb) of ciguatoxin exhibit cardiovascul ar, muscular, and skeletal abnormalities and those injected with higher lev els (1.0-9.0 pg/egg) exhibit significantly reduced hatching success. The se nsitivity of embryonic fish to direct oocyte exposure indicates that matern al transfer of low levels of ciguatoxin may represent an unrecognized threa t to the reproductive success of reef fish and a previously undetected ecol ogical consequence of proliferation of ciguatoxin-producing algae in reef s ystems increasingly impacted by human perturbations. Published by Elsevier Science Ltd. All rights reserved.