California Killifish, Fundulus parvipinnis
California Killifish, Juvenile, Fundulus parvipinnis. Fish caught from a brackish lagoon in San Diego, California, September 2018. Length: 6.6 cm (2.6 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.
California Killifish, Fundulus parvipinnis. Fish caught from within Mission Bay, San Diego, California, August 2019. Length: 7.6 cm (3.0 inches). Catch, photograph, and identification courtesy of Kenneth Tse, Toronto, Canada.
California Killifish, Fundulus parvipinnis. Fish caught from within Mission Bay, San Diego, California, August 2019. Length: 8.2 cm (3.2 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
California Killifish, Fundulus parvipinnis. Fish caught from a brackish intertidal lagoon in San Diego, California, August 2019. Length: 8.9 cm (3.5 inches). Catch, photograph and identification courtesy of George Brinkman, Guelph, Ontario, Canada. Note that the photograph is taken in an aquarium type-setting with the live fish place in a tank a technique that affords a photograph of a fish with is fins extended.
California Killifish, Fundulus parvipinnis. Fish caught from a brackish intertidal lagoon in San Diego, California, August 2019. Length: 8.9 cm (3.5 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).
California Killifish, Fundulus parvipinnis. Fish caught with a cast net from coastal waters of Puerto Adolfo Lopez Mateos, Baja California Sur, October 2018. Length: 12.3 cm (4.8 inches). Identification courtesy of H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.
The California Killifish, Fundulus parvipinnis, is a member of the Topminnow and Killifish or Fundulidae Family, that is known in Mexico as sardinilla cococoo. Globally, there are thirty-nine species in the genus Fundulus, of which five are found in Mexican waters, four in the Atlantic and one in the Pacific Ocean.
The California Killifish have small thick bodies elongated bodies that are compressed toward the rear with a straight of slightly concave upper profile. They have flattened heads with a small oblique mouth that opens in the front that is equipped with conical teeth. The lower jaw is protrusible. The California Killifish are dimorphic being gray-green dorsally and yellowish-brown ventrally. The females have faint stripe along the mid-flank and the males have a series of up to 20 short dark bars along the mid-flank. Males from brackish water have black anal and dorsal fins and are blackish dorsally transitioning to yellow ventrally. The juveniles have scattered spots and short stripes above and below mid-line bars. Their anal fin has 11 to 13 rays with a long base and originates under the middle of the dorsal fin and is elongated in males; their caudal fin is rounded; their dorsal fin has a 10 to 15 rays and has a short base and is located mid-body before the anal fin and above the pelvic fins, their pectoral fins are inserted low on the sides and are rounded with a narrow base; and, their pelvic fins are small and found well behind the pectoral fins. They have 7 to 11 gill rakers. They are covered with smooth scales except that breeding males have spines on the scales.
The California Killifish is a non-migratory species that are found in bays and salt marshes near shore, in brackish lagoons with aquatic vegetation and also in freshwater in close proximity with the ocean at depths up to 2 m (5 feet). They can toleration widely differing levels of salinity, pollution and temperature changes (11oC (52oF) to 25oC (77oF)). They reach a maximum of 13.3 cm (5.2 inches) in length. They feed on planktonic and benthic invertebrates. They are a key component of the food web in coastal marshes being preyed upon by fish, birds, and mammals. Fish reach sexual maturity in six to seven months and reproduction is oviparous with relatively low fecundity levels with each female depositing 60 to 440 eggs that adhere to aquatic vegetation. Most adults perish after breeding with a limited few having life spans of up to three years.
The California Killifish is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found primarily in coastal brackish waters from Magdalena Bay, Baja California Sur northward along the central and northwest coast of Baja.
The California Killifish is a straight forward identification and cannot be confused with any other fish.
From a conservation perspective the California Killifish has not been evaluation but are common over a wide range and should be considered to be of Least Concern. They are utilized for water quality testing including toxicity testing. They are not used extensively by the aquarium trade as they are difficult to maintain.