On the systematic position of Lambrachaeus Alcock, 1895 (Brachyura, Parthenopidae)

Abstract

The systematic position of the unusual, monotypic genus Lambrachaeus Alcock, 1895, is discussed. The genus has long been placed in the Majidae, close to the Inachinae, but its placement there has been questioned by some authors, with one suggestion that it might be a parthenopid instead. However, it was recently transferred to its own tribe, Lambrachaeini Števč ić, 1994, in the Majidae. A detailed study of Lambrachaeus ramifer Alcock, 1895, shows that the genus is clearly a member of the Parthenopidae, with its similarities with inachine majids entirely superficial. We classify the subfamily Lambrachaeinae in the Parthenopidae and revise its diagnosis. The species is also newly recorded from Guam.