if we expose the fish after acclimatization to particular toxin in order to find out LC 50 (96 hours).Should we keep the fish off feed or with feed for that duration. Some literature show that fish should be kept in aquarium without feed. did Starvation affect mortality of fish? or if we keep them by giving regular food up to 96 hours, did feed overcome the effect of toxin or its absorption/metabolism? Kindly explain