Figure 10

Late development of the pectoral fin in T3 treated zebrafish. The arrector ventralis complex was seen as early as 3.9 mm SL (A). By 4.0 mm SL, it was subdivided into the arrector ventralis and arrector-3 (B). In some specimens with the adult state of the pectoral musculature, muscles were slightly underdeveloped and disorganized (C) 4.9 mm SL. In all panels, anterior is to the left, dorsal is to the top.