These fish native to California are small, around 11 cm, but extremely hardy (1)(2). They are green along their back and sides, with a yellow-brown coloration underneath (4). Males have around 20 black bars on each side and breeding males have a dark brown back (4). They are common in bays and salt-marshes close to shore, often hiding in vegetation (1)(4). They are extremely euryhaline, able to tolerate waters between 0 and 128 ppt (2)(4). California killifish can also tolerate large changes in dissolved oxygen and temperature (2). They mainly feed on planktonic and benthic invertebrates (4). California killifish have a brain parasite, a trematode Euhaplorchis californiensis, which affects their motor function, making it more susceptible to predation by birds (3).
(1) Eschmeyer, W. N., & Herald, E. S. (1983). A field guide to Pacific Coast fishes: North America. Boston: Houghton Mifflin.
(2) McGinnis, S. M., & McGinnis, S. M. (2006). Field guide to freshwater fishes of California (Revised ed.). Berkeley, CA: University of California Press.
(3) Shaw, J. C., Korzan, W. J., Carpenter, R. E., Kuris, A. M., Lafferty, K. D., Summers, C. H., & Overli, O. (2009). Parasite manipulation of brain monoamines in California killifish (Fundulus parvipinnis) by the trematode Euhaplorchis californiensis. Proceedings of the Royal Society B: Biological Sciences, 276(1659), 1137-1146.
(4) University of California, Davis. (n.d.). California Killifish.
- Devereux slough