[Crustacea • 2024] Caridina maeklongensis • A New landlocked freshwater Shrimp Species (Decapoda: Atyidae) from the Mae Klong Basin, Thailand

[A–D] Caridina maeklongensis  

   Macharoenboon, Manonai & Jeratthitikul. 2024

[E, F] C. sumatrensis  De Man, 1892

RAFFLES BULLETIN OF ZOOLOGY. 72

Abstract. A newly discovered landlocked shrimp, Caridina maeklongensis, new species, is described from the Mae Klong Basin, western Thailand. The morphology of the new species resembles C. sumatrensis, from which it differs in possessing a shorter rostrum with fewer dorsal teeth, a small number of very large-sized eggs, and a greatly reduced posteromedian projection on the distal end of the telson. The molecular evidence of the mitochondrial 16S rRNA gene also supports the species status of the newly described species. This is the fifth endemic species of Caridina known from Thailand. 

Key words. crustacean, landlocked freshwater shrimp, molecular phylogeny, taxonomy, Southeast Asia

Living habitus specimens of Caridina species from the Mae Klong Basin.
A–D, Caridina maeklongensis, new species: A, paratype male, MUMNH-CAR064-4; B, paratype female, MUMNH-CAR064-1; C, paratype female, MUMNH-CAR064-15; and D, paratype female, MUMNH-CAR064-13.
 E, F, C. sumatrensis: E, male, MUMNH-CAR706-P2; and F, female, MUMNH-CAR706-P1.

Family Atyidae De Haan, 1849 

Genus Caridina H. Milne Edwards, 1837 

Caridina maeklongensis, new species

Etymology. The specific name is from its type locality, the Mae Klong Basin.

Kongkit Macharoenboon, Varitsara Manonai and Ekgachai Jeratthitikul. 2024. Caridina maeklongensis, A New landlocked freshwater Shrimp Species (Crustacea: Decapoda: Atyidae) from the Mae Klong Basin, Thailand. RAFFLES BULLETIN OF ZOOLOGY. 72: 450–468.