Riparian: There are 33 crustacean species found in the Colorado River and its tributaries within Grand Canyon National Park. Of these 33, 16 are considered true zooplankton organisms. Grand Canyon's crustacean species can be grouped into five major types: Calanoid copepods, Cyclopoid copepods, cladocerans, amphipods, and ostracods. The zooplankton crustaceans constitute a significant food source for larval rainbow trout, larval bluehead and flannelmouth suckers, as well as many benthic invertebrates.
Did You Know?
The Cambrian seas of the Grand Canyon were home to several kinds of trilobite, whose closest living relative is the modern horsehoe crab. They left their fossil record in the mud of the Bright Angel Shale over 500 million years ago.