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

killifish A killifish is any of various oviparous (egg-laying) cyprinodontiform fish, including families Aplocheilidae, Pantanodontidae, Cyprinodontidae, Fundulidae, Nothobranchiidae, Profundulidae, Aphaniidae and Valenciidae. All together, there ar ...

(

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 environment ...

) found along the coast of southern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and the Baja California Peninsula. Like the other members of the family, California killifish are small, no more than about 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 fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s are small, while the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

is long, with 11 to 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 ep ...

, 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 environm ...

marsh In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...

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, United States. Located on the Central Coast of California, the city's population was 10,757 as of the 2020 census, up from 10,234 at the 2010 ...

south to

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

in central

Baja California Sur Baja California Sur, officially the Free and Sovereign State of Baja California Sur, is a state in Mexico. It is the 31st and last state to be admitted, in 1974. It is also the second least populated Mexican state and the ninth-largest state by ...

. Between

Goleta Slough The Goleta Slough is an area of estuary, tidal creek (tidal), creeks, tidal marsh, and wetlands near Goleta, California, United States. It primarily consists of the filled and unfilled remnants of the historic inner Goleta Bay about west of ...

and the

Tijuana River The Tijuana River () is an intermittent river, 120 mi (195 km) long, near the Pacific coast of northern Baja California state in northwestern Mexico and Southern California in the western United States. The river is heavily polluted wi ...

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 The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

and

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

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 The Baja California killifish (''Fundulus lima'') is a killifish in the family Fundulidae. It is native to the Baja California Peninsula region of northwestern Mexico. This fish was described by L.L. Vaillant in 1894 with the type locality g ...

''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 The California killifish (''Fundulus parvipinnis'') is a type of killifish (Fundulidae) found along the coast of southern California and the Baja California Peninsula. Like the other members of the family, California killifish are small, no mor ...

Fauna of California Fauna of the Baja California Peninsula Fish of the Gulf of California