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. Author manuscript; available in PMC: 2019 Jun 1.
Published in final edited form as: Dev Dyn. 2018 Apr 16;247(6):832–853. doi: 10.1002/dvdy.24630

Figure 2.

Figure 2

Developmental details of the caudal fin skeleton in stickleback, zebrafish, spotted gar, bowfin, and American paddlefish. (A–D) Three-spined stickleback (Gasterosteus aculeatus), 6.5 mm TL (A), 7 mm TL (B), 7.5 mm TL (C) and 15 mm TL (D). (E–H) Zebrafish (Danio rerio) 4.5 mm TL (E), 5 mm TL (F), 5.5 mm TL (G), and 6 mm TL (H). (I–L) Spotted gar (Lepisosteus oculatus), 17 mm TL (I), 19 mm TL (J), 26 mm TL (K), and 85 mm TL (L). (M–N) Bowfin (Amia calva), 34 mm TL (M–M″) and 99 mm TL (N). (O–Q) American paddlefish (Polyodon spathula), 12 mm TL (O), 65 mm TL (P–P′) and 85 mm TL (Q). (L) is a detail of the posterior part of the notochord of Fig. 1J. For each species, the white elongated triangle indicates hypural 1 as a reference. In A–L the black arrow points at the hypural diastema. In the insert in (N), the oval circles the distal ends of hypurals 2 and 3 showing an unbroken plate of connective tissue. Abbreviations: act, actinotrichia; bd, basidorsal arcualia; bv, basiventral arcualia; bva, basiventral autocentra; cfr, caudal fin rays; darc, dorsal arcualia; dcr, distal caudal radials; ecfr, epichordal caudal fin rays; ep, epurals; ep1+2, compound epural made by the fusion of epurals 1 and 2; f-phy, foramen created by the parhypural; fub, basal fulcra; ha, haemal arches; hd, hypural diastema; hs, haemal spines; hyp1?, putative hypural 1; h10, hypural 10; h20, hypural 20; h30, hypural 30; id, interdorsal arcualia; iv, interventral arcualia; oc, opisthural cartilage; n-hyp1, notch at the base of hypural 1; na, neural arches; nc, notochord; nc-f, notochord point of flexion; ns, neural spine; phy, parhypural; pct, plate of connective tissue; pcta, anterior plate of connective tissue; pctp, posterior plate of connective tissue; p-pHP2, anterior process of the posterior hypural plate; pu1+u1, compound centrum made by the fusion of preural centrum 1 and ural centrum 1; pu2+3, compound centrum made by the fusion of preural centra 2 and 3; pu1+u1+u2, compound centrum made by the fusion of preural centrum 1 and ural centra 1 and 2; sncf, supraneurals of the caudal fin skeleton; un, uroneural; una, ural neural arch; ust, urostyle; u3, ural centrum 3.