Uca crenulata crenulata (Lockington, 1877)

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 260-261

Uca crenulata crenulata (Lockington, 1877)

( Fig. 60C, Pl. 15G)

Gelasimus crenulatus Lockington, 1877: 149 .

Uca crenulata . — Holmes 1900: 75, pl. 1, figs. 7–9. — Rathbun 1904: 190; 1917: 409, pl. 146. — Schmitt 1921: 279, fig. 164. — Johnson & Snook 1927: 399, figs. 357, 358. — Ricketts et al. 1985: 354, fig. 273. — Hubbard & Dugan 1989: 55. — Jensen 1995: 34, fig. 51.

Uca crenulata crenulata . — Crane, 1975: 232, pl. 30 E-I, figs. 70D, G, 101. — Garth & Abbott 1980: 622, fig. 25.46. — Bonfil et al. 1992: 50, fig. 5B.

Diagnosis (modified from Crane 1975). Frontal region narrow, its width less than 0.3 times width of carapace. Orbits nearly straight, suborbital margins with rounded tubercles. Carapace smooth, moderately convex; lateral margins nearly parallel behind acute anterolateral angles, then converging. Male major cheliped with outer surface finely granulated; inner surface with oblique tuberculate ridge running vertically down from dorsal surface, then bending obliquely to run somewhat parallel to gape; two rows of denticles at base of fixed finger. Fingers of old male cheliped longer than those of younger male. Smaller chela of both sexes with fingers equal, gape narrow. Pereopods 2–5 with pile, merus transversely granulate. Abdomen of male with 7 segments. Carapace length to 13 mm in either sex.

Color in life. Carapace grayish white to pale brown. Major chela of male with merus bright red on exterior surface, inner surface of merus, fingers of chela bright white. Palm, inner part of chela yellowish to white. Minor chela pinkish. Merus of pereopod 2 crimson red; otherwise cream-colored; other pereopods marked with cream. Female chelae brownish to cream-colored. See Crane (1975) for a more detailed color description.

Habitat and depth. Upper parts of mud flats and salt marshes, intertidal zone.

Range. Discontinuous, from Goleta, California to Turtle Bay, Baja California, including Santa Catalina I. , California; and San Felipe to La Paz and Guaymas to Tenacatita Bay, western Mexico. Type locality Todos Santos Bay, Baja California. A distinct subspecies, U. crenulata coloradensis ( Rathbun, 1893) , lives at the head of the Gulf of California.

Remarks. Fiddler crabs dig burrows in the upper reaches of mud flats and salt marshes. They manipulate balls of sediment in their mouthparts as they extract detritus and other food material. The burrows, mud balls and tracks are good indication of their presence even if the crabs themselves are not visible. Fiddler crabs today live in California mostly in wildlife refuges and other areas protected from human habitat destruction.