California Killifish

Fundulus parvipinnis

The California Killifish is a small coastal fish found along the southern California coast and the Baja California Peninsula. It typically grows up to 10.8 cm in length and has a thick, oblong body with a squarish tail fin. Its coloration is olive-green above and yellowish-brown below, with brighter colors appearing during the breeding season. This species is adapted to a variety of environments, including shallow bays, estuaries, marshes, and the lower parts of streams. It is known for its tolerance to a wide range of salinities, oxygen levels, and pollution. Divers may encounter the California Killifish in shallow waters, as it is commonly found at depths less than 10 meters. It feeds on a diverse diet of benthic and planktonic invertebrates, such as snails, crustaceans, and insects, often foraging in vegetation flooded by high tides. The species is oviparous, laying single demersal eggs that attach to substrates via weakly adhesive filaments. The California Killifish is classified as Least Concern by the IUCN. It is not a seasonal species and is often used in laboratories for environmental studies. Divers observing this fish should note its preference for coastal and estuarine habitats, where it can be seen navigating through the vegetation.