Morphology of Uca formosensis Rathbun, 1921 (Crustacea: Decapoda: Ocypodidae), an Endemic Fiddler Crab from Taiwan, with Notes on its Ecology

Hsi-Te Shih, Hin-Kiu Mok, Hsueh-Wen Chang and Sin-Che Lee (1999) Morphology of Uca formosensis Rathbun, 1921 (Crustacea: Decapoda: Ocypodidae), an endemic fiddler crab from Taiwan, with notes on its ecology. Zoological Studies 38(2): 164-177. Uca formosensis Rathbun, 1921, is an endemic fiddler crab species from Taiwan. The taxonomy of this species has long been constrained by the paucity of study material. Crane (1975) placed U. formosensis as a member of the subgenus Thalassuca, but important characters, like its handedness, presence of enlarged teeth on the fingers of the female’s minor chela, structures of the anterolateral margin, suborbital margin, orbital floor, degree of arching of the carapace, and habitat preference, suggest that this classification is incorrect. It is suggested that U. formosensis should be excluded from the subgenus Thalassuca. In this study, a historic review is provided of the species and notes on its distribution, variation of morphology (chela types), live coloration, and taxonomy are included.