The California killifish (''Fundulus parvipinnis'') is a type of

killifish A killifish is any of various oviparous (egg-laying) cyprinodontiform fish (including families Aplocheilidae, Cyprinodontidae, Fundulidae, Profundulidae and Valenciidae). All together, there are 1,270 species of killifish, the biggest family ...

(

Fundulidae Fundulidae is the family of topminnows and North American killifishes. Distribution The 46 species are native to North America as far south as Yucatan, and to the islands of Bermuda and Cuba, occurring in both freshwater and marine environments ...

) found along the coast of southern

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

and

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

. Like the other members of the family, California killifish are small, no more than about 11 cm in length. The body is rather thick and oblong in shape, with almost no narrowing of the caudal peduncle, and a squarish tail fin. The pelvic fins are small, while the anal fin is long, with 11-13 rays. They are olive-green above, and a yellowish brown below; during breeding season, the back become dark brown, while the belly and paired fins become bright yellow. They are

coastal fish Coastal fish, also called inshore fish or neritic fish, inhabit the sea between the shoreline and the edge of the continental shelf. Since the continental shelf is usually less than deep, it follows that pelagic coastal fish are generally epi ...

, occurring in shallow bays,

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es, and the lower parts of streams from

Morro Bay Morro Bay (''Morro'', Spanish for "Hill") is a seaside city in San Luis Obispo County, California. Located on the Central Coast of California, the city population was 10,757 as of the 2020 census, up from 10,234 at the 2010 census. The town ...

south to

Magdalena Bay Magdalena Bay ( es, Bahía Magdalena) is a long bay in Comondú Municipality along the western coast of the Mexican state of Baja California Sur. It is protected from the Pacific Ocean by the unpopulated sandy barrier islands of Isla Magdalena ...

in central Baja California. Between Goleta Slough and the

Tijuana River , name_etymology = , image = Presa Tij 1.jpg , image_size = , image_caption = Dam on the Tijuana River in Mexico. , map = Tijuana River Basin.svg , map_size = 250 , map_caption ...

they occur almost continuously, the frequency of wetlands being sufficient to allow free movement. They tolerate a wide range of salinities, oxygen levels, and pollution. The diet consists of a variety of both benthic and

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

ic invertebrates, anything from snails to crustaceans to insects, often found by foraging through areas of vegetation flooded by high tides. This species and the Baja California killifish ''F. lima'' are the only members of ''Fundulus'' on the west coast of the continent, and are distinct from the rest of the genus, which is limited to the east coast. It has been suggested that they may form a separate genus.

References

* * Peter B. Moyle, ''Inland Fishes of California'' (University of California Press, 2002), pp. 313–315 * {{Taxonbar, from=Q2784109 California killifish Fauna of California Fauna of the Baja California Peninsula Fish of the Gulf of California California killifish