Cone structure and visual pigment content in the retina of the goldfish

摘要: Abstract Histologic examination of the retina in comet goldfish 11 cm long (nose to base tail) reveals at least six distinct varieties cones. Unequal double cones (DC) comprise (LD) and short (SD) members which differ form as well length. Long single (LS) are similar length SD Although evidence indicates that there two subpopulations LS cones, normally they structurally indistinguishable. Short (SS) have short, broad outer segments ellipsoids virtually no myoids. Miniature (MLS) same shape but shorter more slender their nuclei project farther into nuclear layer. (MSS) SS found with those MLS The average cone densities, relative = 1.0 , are: DC (pairs) ≅ 2.0 (total) 1.4–2.0 MSS 0.4–0.8 . form, dimensions, densities do not vary systematically location retina. An irregular mosaic is discernible. In fundus, this fundamentally a rhombic array separated by 20–28 μm ( 1000–2500 SS/mm 2 ). Double sides rhombi whose centers occupied lie corners rhombi, while scattered. has been determined. far periphery rows instead otherwise same. Microspectrophotometric measurement visual pigments, accompanied microscopic identification containing them, strong correlation between structure (cone type) function (visual pigment). LD some contain red-sensitive pigment λ max 625nm other green-sensitive 530nm probable ratio (red):LS (green) 2:1 blue-sensitive 455nm contained