In the fishermen’s nets on a lake near the village of Eyik in the Olenyok district of Yakutia, they discovered strange creatures they had never seen before: these are triops—one of the few living organisms today that appeared on Earth before the dinosaurs. The Latin name of the typical genus is Triops (from the Greek "three-eyed")—these invertebrate arthropods were named for an organ resembling a third eye, although its exact function has not yet been determined. Crustacean triops, covered with a hard carapace, are widespread in the Arctic regions of Yakutia and are about the size of a human fingernail. They resemble horseshoe crabs in shape. They are found in large lakes but more commonly inhabit small bodies of water where there are no fish to eat them at various stages of development. In addition to fish, triops can be eaten by birds. The triops themselves feed on plant debris, on which bacteria develop, and other organisms smaller than them. However, when the opportunity arises, they also feed on fish—if a fish gets caught in the nets, the triops attach themselves to it and "suck it out," and additionally "recycle" aquatic creatures dying of natural causes, acting as "pond cleaners." In the freshwater bodies of Yakutia, besides triops, there are also daphnia and cyclops, and in saltwater, limnocalanids. Here are two new words for today—triops and limnocalanids—both relic creatures. The decline in the numbers of these Red-listed species, which are ecological indicators, is associated with anthropogenic pollution.