Abstract
Micromaldane shackletoni n. sp. is described from the Falkland Islands in the southwest Atlantic. It is only the eighth species of Micromaldane to be recognized worldwide and is a new record of the genus for the Falkland Islands. The main characters of the new species are: up to 23 chaetigerous segments; nuchal organs as rounded ciliated pits with small central grooves anteriorly; two kinds of notochaetae: lancet-shaped chaetae and fine capillaries; neurochaetae as a single row of strongly curved, avicular uncini; a single pre-anal achaetigerous segment and anal plaque funnel-shaped with a crenated edge. This new species is a simultaneous hermaphrodite, only the second report of this reproductive mode in the genus along with Micromaldane androgyne Rouse, 1990. The stages of larval development from internal gametes to external in-tube development are also discussed.