Ontogeny of blackhead seabream vertebral column (A, 1DPH; B, 5-7DPH; C, 9DPH; D, 11DPH; E, 13DPH; F, 17DPH; G, 21DPH; H, 24DPH). Nc, notochord; Na, neural arch; Hy, hypural; Ep, epural; Pp, parapophysis; Ha, haemal arch; Fr, fin rays; Hs, haemal spine; Ns, neural spine; Ur, urostile.