preceded_by Platynereis life cycle stage early metatrochophore stage mid metatrochophore stage 51-60 mmt At a temperature of 18 C this stages lasts from 51.00 hours till 60.00 hours. Developmental stage following Early metatrochophore stage with the following key events: Pigment of the adult eyes clearly visible lateral-dorsally in the episphere. Chaetae outside the body wall, but parapodia not yet formed. Amount of pigment in the adult eyes increases. Chaetae elongate. The gut anlage becomes visible. Additional ring of cells surrounds the stomodeal opening from anterior to posterior. Stomodeum starts to invaginate into the head. Second paratroch forms at the posterior border of the first chaetigerous trunk segments. Increasing number of axons in the commissures. Convergent extension movements start in the ventral neuroectoderm and continue until 72hpf (Steinmetz et al., 2007). Fourth pair of serotonergic cells in the ventral nerve cord. Ventral medial longitudinal muscle starts forming. PdumDv:0000900 platynereis_stage