Figure 1.
Branchial basket of Prochilodus argenteus (10.9 mm SL, 7 DPH–LIRP 5993).
Dorsal view (anterior to left). Dorsal elements not represented on left side. Abbreviations: ACh, anterior ceratohyal; AC, anterior copula; AECb4, accessory element of ceratobranchial 4; BhC, basihyal cartilage; Br, branchiostegal ray; Cb1–5, ceratobranchials; Eb1–4, epibranchials; Hb1–3, hypobranchials; HhC, hypohyal cartilage; Ih, Interhyal; Pb2–4, pharyngobranchials; PCh, posterior ceratohyal; PC, posterior copula.
Figure 2.
Branchial basket of Prochilodus argenteus (12.9 mm SL, 9 DPH–LIRP 5993).
Dorsal view (anterior to left). Dorsal elements not represented on right side and unfolded on left side. Abbreviations: ACh, anterior ceratohyal; AECb4, accessory element of ceratobranchial 4; Bb2–3, basibranchials; BhC, basihyal cartilage; Cb1–5, ceratobranchials; Eb1–4, epibranchials; Hb1–3, hypobranchials; Ih, interhyal; Pb1–4, pharyngobranchials; PCbC, posterior ceratobranchial cartilage; PCh, posterior ceratohyal; PCp, posterior copula;
Figure 3.
Posterior portion of the caudalmost branchial arches of Lophiosilurus alexandri (11.7 mm SL, 8DPH–LIRP 5992).
Right side, in posterior view. Abbreviations: AECb4, accessory element of ceratobranchial 4; Cb3–5, ceratobranchials; Eb3–4, epibranchials.
Figure 4.
Posterior portion of the last right side branchial arches of Pseudoplatystoma corruscans (21.4 mm SL, 26 DPH–LIRP 5987).
Posterior view. A, schematic drawing; B, photograph of a c&s specimen. The bones are not stained (in red) due to the very initial stage of perichondral ossification. Arrowhead points to the accessory element of ceratobranchial 4. Abbreviations: AECb4, accessory element of ceratobranchial 4; Cb3–5, ceratobranchials; Eb3–4, epibranchials.
Figure 5.
Histological section at level of the distal tip of fourth branchial arch of Lophiosilurus alexandri (11.7 mm SL, 8 DPH–LIRP 5992).
The articulation area of ceratobranchial 4 with epibranchial 4, evidencing the initial stage of rising of the accessory element of ceratobranchial 4. Abbreviations: AECb-4, accessory element of ceratobranchial 4; Cb-4, ceratobranchial 4; Cc, chondrocyte; Eb-4, epibranchial 4; HCc, hypertrophied chondrocyte; m. adductor, muscle adductor of the arch 4; arrowhead, chondroblasts layer (flatten cells); star, mesenchymal (undifferentiated) cells. Magnification 400x.
Figure 6.
Histological section at level of the distal tip of fourth branchial arch of Prochilodus argenteus (12.9 mm SL, 9 DPH–LIRP 5993).
The articulation area of ceratobranchial 4 with epibranchial 4, evidencing the initial stage of rising of accessory element of ceratobranchial 4. Abbreviations: AECb-4, accessory element of ceratobranchial 4; Cb-4, ceratobranchial 4; Cc, chondrocyte; Eb-4, epibranchial 4; HCc, hypertrophied chondrocyte; arrowhead, chondroblast layer (flatten cells); star, mesenchymal (undifferentiated) cells. Magnification 400x.
Figure 7.
Histological section at level of the distal tip of fourth branchial arch of Pseudoplaystoma corruscans (21.4 mm SL, 26 DPH–LIRP 5987).
The articulation area of ceratobranchial 4 with epibranchial 4, evidencing the initial stage of rising of accessory element of ceratobranchial 4. Abbreviations: AECb-4, accessory element of ceratobranchial 4; Cb-4, ceratobranchial 4; Cc, chondrocyte; Eb-4, epibranchial 4; HCc, hypertrophied chondrocyte; arrowhead, chondroblast layer (flatten cells); star, mesenchymal (undifferentiated) cells. Magnification 400x.
Figure 8.
Cladogram showing the relations of the Gnathostomata taxa discussed in the present study, as well as the higher groups they represent.
A parsimony ancestral character state reconstruction was made for the accessory element of ceratobranchial 4 and the epibranchial 5. Missing [?] data are indicates at the terminal tips; solid and open squares denote presence or absence of the character, respectively. General relationships were based on [1], [13], [32]–[37].
Figure 12.
Detail of accessory elements in polypteriforms.
A, distal tips of branchial arches of Polypterus sp. (62.5 mm SL, LIRP 7426); B, distal tips of ceratobranchial 4 of Erpetoichthys calabaricus (254.2 mm SL, MZUSP 63077). Abbreviations: AECb, accessory elements of ceratobranchials; Cb1–4, ceratobranchials; Eb1–3, epibranchials; Pb1, pharyngobranchial.
Figure 9.
Dorsal view of chondrichthyan branchial arches.
Anterior to top. Left-side elements not represented. A) Callorhinchus capensis (227 mm SL, ANSP 174852); C) Rhizoprionodon porosus (230 mm TL, UFPB 1445.2); E) Hemiscyllium ocellatum (213 mm TL, AMNH 38151); B, D, F) respective schematic drawings. Abbreviations: Bb, basibranchial; Bh, basihyal; Cb, ceratobranchial; CE, composite element (Eb4?+Eb5?+Pb4+5); Ch, ceratohyal; Eb, epibranchial; Hb, hypobranchial; Hyo, hyomandibula; Pb, pharyngobranchial; Ph, pharyngohyal.
Figure 10.
Dorsal view of chondrichthyan branchial arches.
Anterior to top. Left-side elements not represented. A) Squatina californica (255 mm SL, AMNH 55686); C) Narcine brasiliensis (166 mm TL, UERJ 1176.4); E) Taeniura lymma (310 mm TL, AMNH 44079); B, D, F) respective schematic drawings. Abbreviations: Bb, basibranchial; Bh, basihyal; Cb, ceratobranchial; Ch, ceratohyal; Dp, dorsal pseudohyoid; Eb, epibranchial; Hb, hypobranchial; Hyo, hyomandibula; Pb, pharyngobranchial; Vp, ventral pseudohyoid.
Figure 11.
Branchial basket of Polypterus sp. (62.5 mm SL, LIRP 7426).
Dorsal view, anterior to top. Right-side elements not represented. Abbreviations: ACh, anterior ceratohyal; AECb, accessory elements of ceratobranchials; Bb, basibranchial; Cb1–4, ceratobranchials; Eb1–3, epibranchials; Hb1–3, hypobranchials; Pb1, pharyngobranchial; PCh, posterior ceratohyal; VHh, ventral hypohyal.
Figure 13.
Posterior portion of the last right side branchial arch of Pimelodus ortmanni (88.1 mm SL, LIRP 10053).
Arrowhead points to the accessory cartilaginous element of ceratobranchial 3. Abbreviations: AECb4, accessory element of ceratobranchial 4; Cb3–5, ceratobranchials; Eb3–4, epibranchials.