Eye development and the role of vision during Siberian sturgeon early ontogeny

A. Rodríguez, E. Gisbert-2002

Journal of Applied Ichthyology, 18(4-6): 280-285

Abstract:

At hatching, Siberian sturgeon larvae (Acipenser baerii) possess an undifferentiated lens and retina. The eye begins to differentiate at 3 days post-hatch (d.p.h.), and an external layer of cylindrical epithelium, rudimentary retina with some melanosomes, as well as simple tissue which constituted the crystalline lens, could be distinguished. Seven layers were formed in the retina at 5-6 d.p.h.: the pigment epithelium, the outer nuclear layer (consisting of two types of photoreceptor cells, rods and single cones), the outer plexiform layer, the inner nuclear layer (consisting of horizontal, amacrine and bipolar cells), the inner plexiform layer, the ganglion cell layer and optic nerves were also developed. At 7 d.p.h., the visual system was differentiated completely; the only noticeable changes detected in the eyes were increases in diameter and density of rods and cones. The retina of Siberian sturgeon larvae is relatively simple, containing only two morphologically distinct photoreceptors, rods and single cones. The relationship between eye differentiation and organization in relation to larval behaviour is discussed.

(Centro de Investigaciones Científicas, Universidad Jorge Tadeo Lozano, Calle 22 No 3-30, Bogotá, Colombia., E-mail: adriana@porthos.bio.ub.es)

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