Figure 15 in The elasmoid scales of teleosts: from structure to bioinspired materials

Figure 15. – Cyprinus carpio. One step trichrome. Vertical section of the anterior margin of the scale. A thick membrane stained in green is observed between the epidermis and the dermis. Within the dermis, the peripheral scleroblasts form a rim around the margin of the scale (arrowheads). The elevation corresponds to the formation of the first circulus (arrow). Figure 16. – Carassius auratus. TEM. Section of the margin of the scale. A thin microfibrillar membrane (arrow) separates the epidermis (ep) from the dermis (d). Scale pocket cells (spc) form a rim around the scales and line the scleroblasts. The external layer, the first layer to be formed, is deposited between the episquamal scleroblasts (es) and the hyposquamal scleroblasts (hs). Figure 17. – Carassius auratus. Indirect immunofluorescence visualising microtubules in the episquamal scleroblasts. A: Phase constraste. B: Tyrtubulin Mts distribution. Mts radiate from the MTOCs (microtubule organising centre) in cells located between two circuli (c). Figure 18. – Carassius auratus. TEM. Episquamal scleroblats lining the external layer. Figure 19. – Margin of the scale. Elevation of the external layer forming a circulus (c). Figure 20. – Carassius auratus. TEM. Episquamal scleroblast (es) where cytoskeletal elements are coaligned with the thin collagen fibrils (cf). Figures 21-23. – Carassius auratus. TEM. Scales treated with rapid freezefixative procedures. Mineralization of the external layer. 21: Needle-shaped crystals are deposited in the interfibrillary spaces (arrow). 22: Clusters of crystals are randomly dispersed. 23: Mineralized external layer. Figure 24. – Carassius auratus. TEM. Section of a partially demineralized circulus. The external layer (el) is composed of network of randomly dispersed collagen fibrils. A thin layer of microfibrillar material is deposited on one side of the circulus. bp: basal plate; es: episquamal scleroblast. Figure 25. – Carassius auratus. TEM. Demineralized section. Detail of the organic material of the limiting layer (ll) made of a thin microfibrillar meshwork and the external layer (el) composed of thin collagen fibrils embedded in a matrix. Figure 26. – Cyprinus carpio. TEM. Demineralized section of the upper part of the scale. Bundles of collagen fibres forming Sharpey-fibre-like bundles (Sf) cross the external layer (el) and the limiting layer (ll).