The lateral line system develops over the plastic hatching period, and we were interested to compare lateral line development with the ontogeny of HGCs as a possible mechanism to regulate mechanosensorycued hatching. We did not observe neuromasts in 2-day-old embryos. Well-developed neuromasts with a kinocilium and stereocilia were first observed in 3-dayold embryos (Fig. 8A), forming a row above the eye (Fig. 8B, C). The lateral line was visible on the snout by 4 days (Fig. 8D). By 5 days, the lateral line was distinct on the snout and above the eyes (Fig. 8E, F).