WHAT ORGANISMS ARE USED IN WET TESTS?
Species used for WET tests must be sensitive to toxic substances, necessary for the overall health of the food chain, and representative of the indigenous population present in the possible area of impact of the test material. These so called “indicator organisms” are used to estimate what may be happening in the environment when the effluent is introduced. All of the species required by the WDNR have been used in toxicity tests for many years. The species Ceriodaphnia dubia belongs to a group of freshwater microcrustaceans, and may be referred to as water fleas, zooplankton, cladocerans, or daphnids. These invertebrates are a major component of the freshwater zooplankton and are the dominant planktivorous (algae-eating) herbivores in lakes. They are abundant in ponds, quiescent sections of streams and rivers, and lakes throughout North America. The selection of C. dubia for routine use in toxicity testing is appropriate for a number of reasons, including: 1) they are broadly distribut
