Fig. 1
From: Nervous system development in the Pacific oyster, Crassostrea gigas (Mollusca: Bivalvia)
Stages of Crassostrea gigas larval development. Light microscopy images. Early (a), middle (b), and late (c) trochophores and early (D-hinge, d), middle (e), and pedi-umbo-stage (f) veligers. Abbreviations: ad - anterior adductor, ep – episphere, es – esophagus, hp. – hyposphere, in – intestine, m – mouth, pmo – presumptive mouth opening, pt. – prototroch, ret. – retractors, s – shell, sg – shell gland, st – stomach, tt – telotroch, u – umbo, v – velum. Scale bars = 20 μm