Syncaris pasadenae (Pasadena Freshwater Shrimp)

[Melanie]

Pasadena shrimp

last collected in 1933

All known specimens of the presumed extinct freshwater shrimp species Syncaris pasadenae. fonnerly
known from the Los Angeles River and other lowland stream sites in southern California, were examined.
Existing specimens are housed in the Natural History Museum of Los Angeles County, California
Academy of Sciences, or U.S. National Museum of Natural History, Smithsonian Institution, Washington,
D.C. Syncaris pasadenae is diagnosed and redescribed and compared to its only congener, Syncaris
pacifica, an extant species restricted to a few small coastal streatns in northern California (Marin. Napa,
and Sonoma counties). Syncaris pacifica is also redescrihed. Salient and consistent differences between
the species are the dorsal dentition of the rostrum and the number of pereopods bearing exopod.s,
a character often associated with higher-level taxonomic differences in the past. The distribution of the
species and the position of the genus within the family Atyidae are discussed.

full description

atiniui.nhm.org/pdfs/11412/11412.pdf

[Sebbe]

The species was known from the Los Angeles River drainage, in streams near San Gabriel and Pasadena (Los Angeles County) and Warm Creek (San Bernardino County), California (USA). The species is only known from approximately 100 specimens, collected between 1897 and 1933 (Martin and Wicksten 2004). The most recently collected specimens were in 1933. Extensive surveys for the species have taken place since 1968 and continue sporadically to the present day, surveys have extended from the Mexican border north to Santa Barbara (Martin and Wicksten 2004), but no further specimens of the species have been found. The habitat of the species throughout its known historical range has been destroyed by channelization and urbanization and now forms part of the Greater Los Angeles area. The species is thus considered to be Extinct.

www.iucnredlist.org/details/21250/0