A first recordof Pleopis schmackeri (Poppe,1889) (Branchiopoda, Onychopoda) in the Guanabara Bay, Rio de Janeiro, Brazilis described.This marine cladoceran species occurred in zooplanktonic samples obtained on June 26, 2000, with densities ? 4.0 ind.m-3. Its presence may berelated with inflow of coastal waters to the bay.
Cladocera; Pleopis schmackeri; zooplankton; Guanabara Bay; Brazil