The fairy shrimp, ''Phallocryptus fahimii'', is a

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

crustacean discovered in 2017 from a

seasonal lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

in the Lut Desert in southeast Iran. It's a heat-resistant crustacea living in a lake with water temperatures reaching . It is the fifth known species to be discovered in the genus ''

Phallocryptus ''Phallocryptus'' is a genus of crustaceans within the family Thamnocephalidae Thamnocephalidae is a family of crustaceans with wide distribution including Western Australia, Southern Africa and South America. It was originally described as a ...

''. It received its name after the late Hadi Fahimii, a conservationist who took part in the expedition of the Lut Desert and died in 2018 from an airplane crash. Morphologically, this newly discovered species shows minimal differences from its relatives in the Phallocryptus genus. A distinguishing characteristic of this fairy shrimp is that it can lay its eggs in desert sand for decades while they await the rare presence of water. ''P. fahimii'' developed these unique characteristics due to its harsh environmental conditions throughout the Lut Desert, which in Persian, translates into “desert of emptiness.” Dr.Hossein Rajaei, one of the researchers that made the shrimp discovery, suggested, “they gave it this name because many people believed there was no life in this desert.”

Description

Size

The female shrimp is around long and the male shrimp is around long.

Morphology

''Phallocryptus fahimii'' is most closely related to the Mongolian '' P. tserensodnomi''. Males can be differentiated based on the relatively long frontal organ, the strong curvature of the labral distal process and the usual lack of a ventrolateral spine of the genital segment. The morphological differences between the new shrimp and the Mongolian fairy shrimp, ''P. tserensodnomi'', were slight: a longer frontal organ, and curvier antennae. For about 1–2 months, the fairy shrimp swim upside down around their lakes, laying eggs before they die or the pool dries up. Eggs can last decades, even when the lakes have been completely dried up. When water begins to come back due to rainfall, the eggs drink the water and begin to hatch.

Distribution

''Phallocryptus fahimii'' was discovered within an evaporating lake in the hottest desert in the world. The ''Phallocryptus'' genus has been known to consist of highly restrictive geographic distributions. One reason why its distributions are highly restrictive is because they rely on seasonal pond formation. Although ''P. fahimii'' hasn't been discovered anywhere else, its ''Phallocryptus'' relatives have been found in other environments such as ''P. tserensodnomi'' being found in Mongolia and ''P. spinosa'' being found elsewhere in Iran.

Habitat and ecology

''Phallocryptus fahimii'' is located in the Lut Desert, known as the “thermal pole of the Earth” where temperatures reach up to . Located between 33° and 28° parallels, this desert holds the current record for the highest ever-recorded surface temperature. The Lut desert is the second largest desert in Iran, at around . It harbors diverse animal and

archaeal Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebact ...

life, but no permanent aquatic

biotopes A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. ''Biotope'' is almost synonymous with the term "habitat", which is more commonly used in English-speaking countrie ...

, such as ponds. The ephemeral pools are filled by seasonal floods which are derived from spring precipitation. Ephemeral pools are basins that remain flooded periodically throughout the year, but won't hold water if rainfall is insufficient. Temperatures can range from during the day to at night. Sabrina Imbler in The New York Times, September 21, 2020, described the living environment for this species when she wrote, “For a month or two, the fairy shrimp frolic, swimming upside-down in their ephemeral lakes and laying their eggs before they die or the pool dries up, whichever comes first.”

References

{{Taxonbar, from=Q102346241 Anostraca Freshwater animals of Asia