Fig. 4

Development of the pectoral fins of mudskipper larvae and juveniles. Dorsal (a–d), ventral (e, i), and lateral views (f–h) views of planktonic larvae at TL 4.0–14.5 mm stages (a–f; n = 1 each stage) and benthic to amphibious juveniles at TL 18.6–19.2 mm stages (g–i; n = 1 each stage). Arrows in (b, c) indicate the boundary between the endoskeletal disc and the fin fold. Arrowheads in (e, f) indicate fin rays. af, apical fin fold; ed, endoskeletal disc; fr, fin ray; ope, operculum; pel, pelvic fin. Scale bars, 100 µm in a-e; 500 µm in f–i