Rainwater Killifish
Lucania parva
- Least concern
- Card rarity: Common
- Fish

The rainwater killifish is a small silvery fish with yellow flashes and diamond shaped scales that is widespread from Cape Cod, Massachusetts, through to Tampico, Mexico, with occurrences reported on the Yucatán peninsula. It is commonly found in large numbers in fresh to brackish estuarine environments, and inland in parts of New Mexico, Texas and Mexico. It feeds on various aquatic invertebrates. It can reach up to 7 centimetres (2.8 in) total length.
Classification
- Class
- Actinopterygii
- Order
- Cyprinodontiformes
- Family
- Fundulidae
- Genus
- Lucania