Figure 9

The latest stages of metamorphosis of Phoronopsis harmeri . (A) Metamorphic animal, which underwent all catastrophic changes in 30 minutes after metamorphosis start. (B-H) A 3-day-old juvenile. (A) The head region of metamorphic animal viewed from the oral side; SEM. (B) The head region of live juvenile viewed from the oral side. (C) The cross section of the tentacle: new postoral ciliated band is formed (the long microvilly of laterofrontal cell are shown by double arrowheads). (D) The laterofrontal cell, which is associated with laterofrontal neurite bundle (arrowheads). (E) The mediofrontal neurite bundle (arrowheads). (F) The medioabrfontal neurite bundles (arrowheads). (G) The lateroabfrontal neurite bundle (arrowheads), which is associated with gland cell. (H) The main nerve ring: sensory (blue) and nonsensory (pink) perikarya. Abbreviations: az – abfrontal zone; bl – basal lamina; bv – blood vessel; cc – coelomic lining; dcv – dense-core vesicle; dt – definitive tentacle; ec – erythrocyte; ep – epistome; fz – frontal zone; G – Golgi apparatus; gc – gland cell; laz – lateroabfrontal zone; lfc – laterofrontal cell; lfz – laterofrontal zone; m – mouth; mc – muscle cell; mi – microvilli; mt – microtubule; n – nucleus; nf – nerve fiber; pp – remnants of the hood; pt – posterior part of the larval body with the telotroch; yt – youngest tentacle.