Visual projection upon the optic tectum in foveate marine teleosts

Schwassmann, Horst O.

doi:10.1016/0042-6989(68)90054-0

Cited by 50 publications

(25 citation statements)

References 18 publications

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“…In another serranid, the kelp bass, Paralabrax, an acute temporal zone of approximately 3.3 x 104 cells/ mm2 has been found [Schwassmann, 1968]. This foveal region is comparable to that in C. miniatus and exhibits a 12-fold increase in ganglion cell density.…”

Section: Coral Codmentioning

confidence: 55%

“…These early works were qualitative, and only recently has the resolution of acute zones been subject to quantita tive analysis. Such analysis of the retinal ganglion cell layer in teleosts has so far been restricted to four spe cies: the coral fish, Microcanlhus strigatus [Yamanouchi, 1956], the kelp bass, Paralabrax clathratus [Schwassmann, 1968], the scorpaenid, Sebastiscus marmoratus [ho and Murakami, 1984] and a filefish, Navodon modestus [Ito and Murakami, 1984].…”

Section: Introductionmentioning

confidence: 99%

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Retinal Topography in Reef Teleosts

1988

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The retinal ganglion cell layer of five species of teleosts has been studied from Nissl-stained whole-mounts and the distribution of neuronal elements determined quantitatively. Isodensity contour maps of neurons in the ganglion cell layer revealed areas of high density (areae centrales) predominantly in the temporal retina, but other areae were also found in the nasal and dorso-nasal retina. Neuronal densities within the ganglion cell layer at the areae centrales ranged from 0.4 x 10⁴ to 4.7 x 10⁴ cells/mm². Species that were found to lack a horizontal streak of high ganglion cell density appear to be those whose behaviour suggests they possess an interrupted view of the sand-water horizon and are ''enclosed'' species. Concentric density contours around an area centralis seem to be associated with enclosed environments. The relationship between retinal topography and niche is also discussed.

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Section: Coral Codmentioning

confidence: 55%

Section: Introductionmentioning

confidence: 99%

Retinal Topography in Reef Teleosts

1988

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“…Of the seven families that were inferred to have RHCDs, four (dragonets, hawkfish, sand perch, and flatheads) spend most of their time relatively motionless. Many of the sea basses (Serranidae) that have foveas (Schwassmann, 1968) are similarly motionless, so it might be thought that a stationary platform for the eyes was a prerequisite for possession of an RHCD. However, the blennies and the jawfish are also motionless and lack the RHCD, and the puffer fish, wrasses, and leatherjackets, all ofwhich move around the water column quite actively, have the RHCD.…”

Section: Discussionmentioning

confidence: 99%

Retinal growth in foveated teleosts: nasotemporal asymmetry keeps the fovea in temporal retina

Easter

1992

J. Neurosci.

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Fish retinas continue to grow throughout life by adding neurons at the margin, with the result that cells born at a peripheral site are steadily displaced toward the center of the enlarging retina. This presents a functional problem for fish with specialized temporal areas such as a fovea--how to reconcile continual growth with the maintenance of a temporal location for the fovea. One possibility is that the retina grows asymmetrically, with most new retina added nasally, relatively little temporally. I have tested this hypothesis by evaluating retinal growth in marine teleosts from 15 families, both foveated and unfoveated. The pattern of growth was revealed by exploiting the fact that each new generation of ganglion cells sends its axons into the optic nerve as a cohort; small grains of the carbocyanine dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl- indocarbocyanine were applied to various sites in the cross section of the optic nerves of adults, and the retrogradely labeled cell bodies in the retina were visualized in whole-mounts. The labeled cells lay in annuli, each one a generation of ganglion cells. Representatives of seven of the families showed clearly asymmetric growth: the labeled annuli were close together on the temporal side and more distant nasally, the embryonic fissure curved from its ventral origin toward the temporal side, and in six of these families, labeled fibers from temporal retina skirted the fovea. Members of the other eight families, without specialized areas, had more symmetric retinal growth: labeled annuli were equally spaced on all sides, the embryonic fissure was vertical, and there were no skirting fibers. The following hypothesis is supported: the retina grows asymmetrically, and maintains the area for acute vision oriented toward the anterior field.

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“…In three species of bass, Schwassmann [1968] was able to demonstrate a five-fold magnifi cation of the foveal projection and showed that ganglion cell density was six times greater than elsewhere in the retina. Thus within one class of vertebrates, we have examples of a quite simple pattern and of other com plex patterns all of which apparently relate to retinal specializations more readily than to evolutionary status.…”

mentioning

confidence: 99%

The Topography of the Visual Projection to the Mesencephalon: A Comparative Survey

Kruger¹

1970

Brain Behav Evol

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Visual projection upon the optic tectum in foveate marine teleosts

Cited by 50 publications

References 18 publications

Retinal Topography in Reef Teleosts

Retinal Topography in Reef Teleosts

Retinal growth in foveated teleosts: nasotemporal asymmetry keeps the fovea in temporal retina

The Topography of the Visual Projection to the Mesencephalon: A Comparative Survey

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