The Gruta del Arco Freshwater Prawn, which was described in 1973, is known only from its type locality: a small freshwater lake in the Grutas del Arco in the municipality of La Trinitaria, Rancho de San Rafael del Arco, Chiapas, Mexico.
This locality is now contaminated and the species wasn’t found during recent searches, it is now probably extinct.
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edited: 13.11.2021
Mascarene Freshwater Prawn (Macrobrachium hirtimanus)
The Mascarene Freshwater Prawn was described in 1811, the species was apparently endemic to the islands of Mauritius and Réunion, Mascarene Islands, where it is known to have inhabited several rivers.
The species was last recorded in the 1980s on Réuinion and was not found in later surveys, so is now either extremely rare or may already be extinct. [1][2]
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References:
[1] P. Keith; E. Vigneux: First capture of Macrobrachium lepidactylus (Hilgendorf, 1879) (Palaemonidae) on Réunion Island, followed by a commentary on Macrobrachium hirtimanus (Olivier, 1811). Crustaceana 73(2): 215-222. 2000
[2] P. Keith: Freshwater fish and decapod crustacean populations on Réunion Island, with an assessmemnt of species introductions. Bulletin Français de la Pêche et de la Pisciculture. 364: 97-107. 2002
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edited: 24.04.2019