Rainwater Killifish

Diet and feeding

The FishTraits compilation records these diet categories for this species: algae or phytoplankton; aquatic or other vascular plants; invertebrates or larval fish. These are broad categories, not a claim that every individual consumes every example in a category.

Reported feeding positions include bottom feeding. The compilation combines published observations; diets can vary with age, locality, and available food.

Habitat preferences

Reported habitat associations include medium to large rivers, streams and small rivers.

The source records associations with clay or silt, sand, vegetation. An association indicates reported use, rather than an exclusive requirement.

The species is classified as tolerant of a broad range of salinities. This flag does not specify a salinity range for aquarium care.

Reproduction and parental care

The compilation reports a representative maturity age of 0.4 years. Its maturity field summarizes mean, median, or modal estimates, usually for females; male estimates can be used when female data are unavailable. It is not a fixed age at which every fish first breeds.

Recorded spawning months are Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec for the source’s reporting region (AL). This is a regional calendar, not a range-wide schedule.

Size and recorded longevity

FishTraits reports a maximum total length of 6.2 centimetres. Some entries use an estimated asymptotic length; this value should not be treated as a certified record catch.

Native range

Marine, but enters freshwater from Massachusetts to Mexico. Ascends the Pecos River, Texas and New Mexico (Hubbs and Miller 1965; Page and Burr 1991).

Introduction history

Many introductions likely were the result of contaminated stock (Sigler and Miller 1963; Hubbs and Miller 1965; Moyle 1976a, 1976b). In Utah, Rainwater Killifish arrived as a stock contaminant in a shipment of largemouth bass (Sigler and Sigler 1987). In northern California and Oregon, Rainwater Killifish may have been transported as eggs on planted oysters (Hubbs and Miller 1965; Moyle 1976a, b) or with ballast water from the Atlantic Coast (Hubbs and Miller 1965). In southern California it was a contaminant in a shipment of largemouth bass (Hubbs and Miller 1965; Moyle 1976b). Hubbs and Miller (1965) indicated some introductions may have resulted when the species was stocked along with Gambusia during mosquito control operations or from aquarium release, but that these routes were less likely than stock contamination. Most of the original introductions in the western United States apparently occurred during the 1940s and 1950s (Hubbs and Miller 1965). The species was introduced into the Great Swamp in New Jersey in 1969 (Stiles 1978) and into Texas in about 1980 (Hubbs et al. 1991), but the reasons for these introductions were not given.