Fig. 2

Characterization and timing of shell development in Crepidula atrasolea. Dark field and confocal images of fixed C. atrasolea embryos from approximately 8 days post-fertilization (dpf) to approximately 15 dpf at 20 °C. Fixed embryos were stained with wheat germ agglutinin (WGA) and imaged at the 20x objective on a confocal microscope. Cartoons highlight changes in shell morphology during development. In mid ovoid staged embryos (A), WGA stains nuclear membranes throughout the embryo. WGA begins to mark the shell field starting at the late ovoid stage (B). WGA continues to mark the developing shell throughout the organogenesis stages (C-E). WGA also marks the velar lobes, larval kidney, and foot in veliger staged embryos (F-K) Hoechst is shown in gray and WGA in yellow. fr, foot rudiment; ft, foot; hv, head vesicle; lk, larval kidney; in, intestine; ir, intestinal rudiment; oc, ocellus; sf, shell field; sfe, shell field edge; st, stomodeum; tn, tentacles; ve, velar lobes. Scale bars each represent 100 μm