Abstract Information concerning the morphology of Dendrocephalus brasiliensis Pesta, 1921 is currently fragmented. This study reviewed the morphological structures described previously and new features (e.g., antenna-like structures and gonopod). We review the distribution of this species and also expand the geographic distribution of D. brasiliensis in the state of Alagoas. The specimens were obtained from fish-breeding tanks in Porto Real do Colégio, Alagoas, Brazil, in November 2012. Several morphological structures of D. brasiliensis are described in greater detail, including all branches and sub-branches from the frontal appendage and thoracopods from one population and compared to other species.

The Anostraca is a diversified crustacean group inhabiting essentially in temporary wetlands on all continents. The genus Dendrocephalus sensu stricto is endemic to tropical or subtropical Neotropical fresh water pools. Of the 13 described species, four are reported from Brazil. Species identification is based on morphological differences on the complex frontal appendage, the anterior thoracopods, and the gonopods. After a detailed comparison of the different Brazilian populations, we developed an illustrated identification key based on the variations of the frontal appendage. This key includes a new undescribed species recently found in Northern Minas Gerais. We present a simple tool to identify Brazilian Dendrocephalus species in order to encourage more studies on this generally neglected genus.