Unsure if the shrimp was a new species, Dr. Rajaei asked Martin Schwentner, the paper’s lead author and a researcher at the Natural History Museum of Vienna who studies similar crustaceans in Australia, to take a look. When Dr. Schwentner compared the genetics and morphology of the shrimp to the four known species in the genus Phallocryptus, he determined that the shrimp was a new, fifth species. The morphological differences between the new shrimp and a Mongolian fairy shrimp, Phallocryptus tserensodnomi, were slight: a longer frontal organ, and curvier antennae.
According to Dr. Alonso, the researchers did not make an unequivocal distinction between the morphology of the new species and that of P. tserensodnomi, which is found in Mongolia, and P. spinosa, which is found elsewhere in Iran. Alireza Sari, a crustacean biologist at the University of Tehran, said he suspected that several of his past discoveries of P. spinosa may have been P. fahimii.
“The morphology is tricky,” Dr. Schwentner said. “But the genetic difference made it obvious that it was a different species.”
Although the shrimps survive just fine in the desert, lasting 10 days in the Lut is a feat for any human. Temperatures range from 122 degrees Fahrenheit during the day to 35 degrees Fahrenheit at night. The team only had enough water to drink and wash their hands once or twice a day. Swirling dust storms frequently cocooned them in their cars for hours at a time and even broke several cameras as tiny grains of dust scratched the lenses. “The first five days, the Lut is beautiful and exciting,” Dr. Rajaei said. “Then it is annoying.”
One night, a dust storm concluded, unexpectedly, in fat droplets of rain. “We could not help it, we started dancing,” he said. “I felt like I lost a part of my soul in the desert.”
The researchers named the new fairy shrimp after Dr. Fahimi, the herpetologist on the expedition, who died in a plane crash in Iran a year after the trip to the Lut. As researchers have begun to publish their findings from the expedition, they have also memorialized Dr. Fahimi in the name of a spider, Oecobius fahimii, as well as a snake.
The lake where P. fahimii swam, once the size of two swimming pools, has since evaporated, and no one can be sure when it will fill again. Until then, the eggs in the sand lie in wait.