Figure 3

Muscle ontogeny of Neocaridina heteropoda. a Macroscopic image of adult. b and d blend-projection-, c-g maximum intensity projections of confocal image stacks taken from whole mount fluorescent staining. Nuclear stain (TOPRO-3): cyan (b), grey (d), blue (e-f); muscle stain (Myo16C6-Cy3): red (c, e and f); muscle stain (phalloidin-ALEXA564 ): multiple artificial colors (g). b Egg-nauplius stage. Arrowheads mark the ectoteloblast row in the caudal papilla. c-g Ventral views of semaphoronts Nh I - Nh IV. In c and e-g only left body half is shown. c Nh I. Postnaupliar appendage anlagen are not seen but the caudal papilla is elongated and flexed anteriorly. Muscle precursors st, st-2 and a2-m1, md-l1 and md-m are present. d Dorsal view of Nh I caudal papilla (as in Figure 2b). e Nh II. st-1. a1-m, a2-l1, a2-l2, mdl2 are present, as well as anterior longitudinal muscle precursors lmp-mx2 and lmp-d . Intrinsic muscles appear (asterisks). f Nh III. Novel lateral extrinsic precursors: a2-l3, mx1-l1, mx1-l2, mx1-l3, mx2-l1, mx2-l2, t1-l1 and t1-l2. Novel medial extrinsic precursors: mx1-m, mx2-m and t1-m. Novel longitudinal muscle precursor: lmp-mx1. g Nh IV. Individual precursors or groups of precursors are reconstructed and assigned artificial colors for better orientation. The color code is also applied to the labels. a1-m is no longer seen. lmp-t1 is not shown. Medial precursors: a2-m2, mx1-m1, mx1-m2, mx2-m1, mx2-m2, t1-m1 and t1-m2. Abbreviations: Ol optic lobes, Cp caudal papilla, A1, A2, Md, Mx1, Mx2, T1 appendage anlagen. Scalebars are 5 mm in a, 50 μm in b–e, 100 μm in f and g.