Fine structure and development of the retina of the grenadier anchovy Coilia nasus (Engraulididae, Clupeiformes)

Abstract

A study of the morphogenesis of the grenadier anchovy retina was undertaken using light and electron microscopy. Five developmental stages from prelarvae 3 days after fertilization to adult fish were studied. In addition to the general morphology of the eye and retina, special emphasis was given to the development of the photoreceptors and pigment epithelium (PE). The earliest retinae showing structural features indicative of a functioning eye are pure cone retinae composed of rows of alternating long and short cones forming a transient, tesselated pattern. At this stage there is a conventional PE containing melanin. In older stages cone rows are separated by the newly formed rods and by PE wedges filled with diffusely reflecting guanine crystallites. The findings are compared with the retinae of other engraulidids and with the development of teleost retinae in general. Moreover, the observed structural changes are discussed with respect to the photic habitat conditions of these anadromous fish that move between coastal waters, estuary, and river.

A morphohistological and histochemical study of hatchery-reared European hake, <i>Merluccius merluccius</i> (Linnaeus, 1758), during the lecitho-exotrophic larval phase

“…The sequence of cellular differentiation in the neuroretina of hake larvae follows the basic pattern seen in other vertebrates (Powers and Raymon 1990, Haacke et al 2001, Falk-Petersen 2005: first differentiation of cone photoreceptors and ganglion cells (hake 4 dph), and consecutively neurons of the inner nuclear layer showing specific sub-stratification (hake 6 dph) and finally developing rods (hake 9 dph). In different fish species, rod photoreceptors have been reported between 5 and 29 dph (Hadedorn and Fernald 1992, Branchet and Bremiller 1984, Haacke et al 2001. It is well known that appearance of pigmentation and developed rod-type photoreceptors in fish retina is indicative of fully developed and functional eyes (Blaxter 1986, Falk-Petersen 2005.…”

“…These changes are coincident with the development of the digestive system to start feeding (Roo et al 1999). The distribution pattern of cells in the ganglion layer of retina varies throughout fish life (Sandy and Blaxter 1980, Blaxter 1986, Powers and Raymon 1990, Haacke et al 2001, Mas-Riera 1991, Bozzano and Catalán 2002 de absorción lipídica en los enterocitos de la región anterior intestinal, así como un marcado proceso de pinocitosis y digestión intracelular en el intestino posterior (inclusiones supranucleares o vesículas proteicas acidófilas). En larvas de 10 dpe se detecta una proliferación de túbulos renales y una diferenciación y desarrollo esplénico, así como la presencia del primer folículo tiroideo.…”

Effect of intermittent light on photoreceptor cells in the rabbit retina

“…[7][8][9][10][11][12][13][14][15][16] In the present study, the photoreceptor damage produced by low-intensity light (EXP-1 group) and high-intensity light (EXP-2 group) was evaluated. At the ultrastructural level, the rabbits exposed to high-intensity light showed disorganization and distention of the outer segment disc membrane, similar to the fi ndings of Organisciak et al 17 By comparison, the outer segment of rabbits exposed to low-intensity light appeared normal.…”

“…[7][8][9][10][11][12][13][14][15][16] Organisciak et al 17 compared retinal light damage in rats exposed to intermittent light with that in rats subjected to continuous light exposure. White and Fisher 18 studied the degree of retinal damage according to the time of day in the albino rat exposed to bright light.…”

Remodeling of the Cone Photoreceptor Mosaic during Metamorphosis of Flounder <i>(Pseudopleuronectes americanus)</i>

“…Because vision can be affected by photoreceptor arrangement and spectral sensitivities, remodeling these features might improve the match between visual function and habitat, as described extensively in a variety of teleost fish species. Teleost retinal remodeling includes several possible developmental changes: (1) new photoreceptor classes may be added by new cell addition or by changes in existing cone morphology, opsin chromophore, or opsin subtype Archer et al, 1995;Hope et al, 1998;Shand et al, 1999Shand et al, , 2002Novales Flamarique, 2000;Zhang et al, 2000;Haacke et al, 2001;Chinen et al, 2003;Cheng and Novales Flamarique, 2004;Mader and Cameron, 2004;Takechi and Kawamura, 2005]; (2) cell classes may be lost by cell death [Bowmaker and Kunz, 1987;Beaudet et al, 1993;Novales Flamarique and Hawryshyn, 1996;Novales Flamarique, 2000;Deutschlander et al, 2001;Allison et al, 2003], or (3) cells might move in relation to one another to form different arrangements Shand et al, 1999;Haacke et al, 2001;Helvik et al, 2001]. In the winter flounder, Pseudopleuronectes americanus , photoreceptors change the peak wavelength sensitivity and physical arrangement when larvae settle into deeper water, providing an excellent model for examining the relationship between photoreceptor cell birth, opsin expression, and physical position.…”