Figure 5

Early development of the caudal fin musculature in T3 treated zebrafish. A general view of the caudal fin and a condensation of cells on its ventral side at 3.4 mm NL (A). Curly muscle fibers in the epaxialis in a fish at 3.6 mm NL (B). Development of the intrinsic caudal muscles started with an outgrowth of the flexor caudalis ventralis and is shown in a fish at 3.8 mm NL (C). Enlarged nuclei in the muscular tissue in a fish at 4.0 mm NL (D). In all panels, anterior is to the left, dorsal is to the top.