Sacramento Splittail

Taxobox | name = Sacramento Splittail
status = EN
status_system = iucn2.3

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image_width = 250px
image_caption = Adult splittail
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Cypriniformes
familia = Cyprinidae
genus = "Pogonichthys"
species = "P. macrolepidotus"
binomial = "Pogonichthys macrolepidotus"
binomial_authority = (Ayres, 1854)

The Sacramento Splittail, "Pogonichthys macrolepidotus", is a cyprinid fish native to the low-elevation waters of the Central Valley in California. It was first described by William O. Ayres in 1854. It is the sole living member of its genus, the Clear Lake splittail "P. ciscoides" having become extinct in the 1970s.

The distinctive feature of the splittail is the larger upper lobe of the tail fin. It also has tiny barbels at the corners of the mouth. The dorsal fin has 9-10 rays, while the pectoral fins have 16-19 rays, the pelvic fin 8-9 rays, and the anal fin 7-9 rays. Color is silver on the sides, with a dusky olive gray on the back; during the breeding season the fins pick up a red-orange tinge, and the males become darker and develop white tubercles on the head and at the bases of the fins.

They feed on bottom-dwelling invertebrates and detritus, generally in areas of low to moderate current. In Suisun Bay, opossum shrimp (mostly "Neomysis mercedis"), amphipods such as "Corophium", and copepods are favorite foods, while in the Sacramento Delta they eat clams, crustaceans, and insect larvae. During periods of high water levels (February/March), splittails will move into flooded areas to look for earthworms. The Sacramento splittail utilizes floodplain habitat for feeding and spawning, and depends upon floodplain habitat for spawning..

Range

Their range is the lower-elevation waters of the Central Valley, extending to San Francisco Bay. Although once found as far north as Redding, they are now only rarely seen in the upper Sacramento River. They were once caught from southern San Francisco Bay and in Coyote Creek (Santa Clara County), but are now restricted to the Sacramento Delta, Suisun Bay, and the lower parts of Sonoma Creek, Petaluma River and Napa River. They are tolerant of moderate levels of salinity and/or alkalinity.

tatus

Splittail were reclassified as a species of special concern by the US Fish and Wildlife Service on September 22, 2003 from their prior classification as threatened due to litigation. [Federal Register 68:55139; September 22, 2003 http://www.fws.gov/sacramento/es/animal_spp_acct/sac_splittail.htm] . The Central Valley's system of sloughs and backwaters maintained by annual flooding has greatly changed. The cause of the decline of this species is under investigation.

ources

* Listed as Endangered (EN A1c v2.3)
*
* Peter B. Moyle, "Inland Fishes of California" (University of California Press, 2002), pp. 146-150
*

References