Palaemonidae Rafinesque, 1815

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 51-52

Family Palaemonidae Rafinesque, 1815

The family Palaemonidae includes a diverse array of tropical species inhabiting coral reefs, estuaries, rivers and caves. Many are specialized and are symbionts of cnidarians, mollusks, echinoderms or tunicates. Being primarily inhabitants of warmer regions, few range as far north as California. One species has been introduced into bays of California and Oregon from the Orient. All of the other resident species in California are marine. Wicksten (1989a) gave a key to all species of the eastern Pacific and nearby freshwater drainages .

Both the first and second pereopods bear chelae. The carpus of the second pereopod is entire, not divided into three or more articles. The second pereopods are especially large and heavy in adult males.

Four additional introduced species have been found California. As of this writing, it is uncertain whether any of them has established a breeding population in the area. Exopalaemon carinicauda ( Holthuis, 1950) has been collected in southern San Francisco Bay ( Wicksten 1997: 43, fig. 1), and E. modestus ( Heller, 1862) at the mouth of the Columbia River and lower Snake River ( Haskell et al. 2006: 311, fig. 1). These estuarine species are native to the Asian coast from Siberia to China and Korea. The two species can be distinguished by the key of Kuris et al. (2007). Macrobrachium rosenbergii ( de Man, 1879) , widely raised in aquaculture, occasionally escapes into the San Francisco Bay drainage. It is widespread in freshwater areas of the Indo-West Pacific region, and can tolerate salt water for short periods of time. Palaemonetes kadiakensis Rathbun, 1902 has been found in freshwater streams draining into San Diego Bay and in marshes and streams around the Salton Sea (St. Amant & Day 1972: 54, as P. paludosus [ Gibbes, 1850]). It is native to the eastern United States. Holthuis (1952: pl. 51 k–n) provided illustrations of this species.