scholarly journals Retinal Topography of Ganglion Cells and Putative UV-Sensitive Cones in Two Antarctic Fishes: Pagothenia borchgrevinki and Trematomus bernacchii (Nototheniidae)

2002 ◽  
Vol 19 (11) ◽  
pp. 1223-1229 ◽  
Author(s):  
Taeko Miyazaki ◽  
Tetsuo Iwami ◽  
Hiroaki Somiya ◽  
V. Benno Meyer-Rochow
Keyword(s):  
Ganglion Cells ◽  
Antarctic Fishes ◽  
Retinal Topography ◽  
Pagothenia Borchgrevinki ◽  
Trematomus Bernacchii

scholarly journals The visual ecology of Holocentridae, a nocturnal coral reef fish family with a deep-sea-like multibank retina

2020 ◽  
pp. jeb.233098
Author(s):  
Fanny de Busserolles ◽  
Fabio Cortesi ◽  
Lily Fogg ◽  
Sara M. Stieb ◽  
Martin Luehrmann ◽  
...  
Keyword(s):  
Visual System ◽  
Reef Fish ◽  
Deep Sea ◽  
Colour Vision ◽  
Ganglion Cells ◽  
Light Sensitivity ◽  
Fish Family ◽  
Visual Systems ◽  
Retinal Topography ◽  
Dim Light

The visual systems of teleost fishes usually match their habitats and lifestyles. Since coral reefs are bright and colourful environments, the visual systems of their diurnal inhabitants have been more extensively studied than those of nocturnal species. In order to fill this knowledge gap, we conducted a detailed investigation of the visual system of the nocturnal reef fish family Holocentridae. Results showed that the visual system of holocentrids is well adapted to their nocturnal lifestyle with a rod-dominated retina. Surprisingly, rods in all species were arranged into 6-17 well-defined banks, a feature most commonly found in deep-sea fishes, that may increase the light sensitivity of the eye and/or allow colour discrimination in dim-light. Holocentrids also have the potential for dichromatic colour vision during the day with the presence of at least two spectrally different cone types: single cones expressing the blue-sensitive SWS2A gene, and double cones expressing one or two green-sensitive RH2 genes. Some differences were observed between the two subfamilies, with Holocentrinae (squirrelfish) having a slightly more developed photopic visual system than Myripristinae (soldierfish). Moreover, retinal topography of both ganglion cells and cone photoreceptors showed specific patterns for each cell type, likely highlighting different visual demands at different times of the day, such as feeding. Overall, their well-developed scotopic visual systems and the ease of catching and maintaining holocentrids in aquaria, make them ideal models to investigate teleost dim-light vision and more particularly shed light on the function of the multibank retina and its potential for dim-light colour vision.

Retinal Topography in Two Species of Baleen Whale (Cetacea: Mysticeti)

2018 ◽  
Vol 92 (3-4) ◽  
pp. 97-116 ◽  
Author(s):  
Thomas J. Lisney ◽  
Shaun P. Collin
Keyword(s):  
Ganglion Cells ◽  
Feeding Strategy ◽  
Visual Fields ◽  
Humpback Whale ◽  
High Density ◽  
Resolving Power ◽  
Temporal Area ◽  
Baleen Whales ◽  
Axial Diameter ◽  
Retinal Topography

Little is known about the visual systems of large baleen whales (Mysticeti: Cetacea). In this study, we investigate eye morphology and the topographic distribution of retinal ganglion cells (RGCs) in two species of mysticete, Bryde’s whale (Balaenoptera edeni) and the humpback whale (Megaptera novaeanglia). Both species have large eyes characterised by a thickened cornea, a heavily thickened sclera, a highly vascularised fibro-adipose bundle surrounding the optic nerve at the back of the eye, and a reflective blue-green tapetum fibrosum. Using stereology and retinal whole mounts, we estimate a total of 274,268 and 161,371 RGCs in the Bryde’s whale and humpback whale retinas, respectively. Both species have a similar retinal topography, consisting of nasal and temporal areas of high RGC density, suggesting that having higher visual acuity in the anterior and latero-caudal visual fields is particularly important in these animals. The temporal area is larger in both species and contains the peak RGC densities (160 cells mm–2 in the humpback whale and 200 cells mm–2 in Bryde’s whale). In the Bryde’s whale retina, the two high-density areas are connected by a weak centro-ventral visual streak, but such a specialisation is not evident in the humpback whale. Measurements of RGC soma area reveal that although the RGCs in both species vary substantially in size, RGC soma area is inversely proportional to RGC density, with cells in the nasal and temporal high-density areas being relatively more homogeneous in size compared to the RGCs in the central retina and the dorsal and ventral retinal periphery. Some of the RGCs were very large, with soma areas of over 2,000 µm2. Using peak RGC density and eye axial diameter (Bryde’s whale: 63.5 mm; humpback whale: 48.5 mm), we estimated the peak anatomical spatial resolving power in water to be 4.8 cycles/degree and 3.3 cycles/degree in the Bryde’s whale and the humpback whale, respectively. Overall, our findings for these two species are very similar to those reported for other species of cetaceans. This indicates that, irrespective of the significant differences in body size and shape, behavioural ecology and feeding strategy between mysticetes and odontocetes (toothed whales), cetacean eyes are adapted to vision in dim light and adhere to a common “bauplan” that evolved prior to the divergence of the two cetacean parvorders (Odontoceti and Mysticeti) over 30 million years ago.

Retinal topography of ganglion cells in immature ocean sunfish, Mola mola

2009 ◽  
Vol 85 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Masakatsu Kino ◽  
Taeko Miayzaki ◽  
Tetsuo Iwami ◽  
Jun Kohbara
Keyword(s):  
Ganglion Cells ◽  
Ocean Sunfish ◽  
Mola Mola ◽  
Retinal Topography

Morphology and mosaic of on- and off-beta cells in the cat retina and some functional considerations

1981 ◽  
Vol 212 (1187) ◽  
pp. 177-195 ◽  
Keyword(s):  
Beta Cells ◽  
Visual Discrimination ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Fine Detail ◽  
Cat Retina ◽  
Retinal Topography ◽  
Dendritic Branching ◽  
Whole Mounts

The beta type of ganglion cell can be subdivided in Golgi-stained whole mounts of the cat retina according to the branching level of the den­dritic tree in the inner plexiform layer. The dendritic branching level of on-beta cells is nearer to the cell body; that of off-beta cells is about 10 μm further outwards. After horseradish peroxidase (HRP) injection into the lateral geniculate nucleus all beta cells were labelled. In this way it is shown that about 55% of all ganglion cells, irrespective of retinal topography, are beta cells. The spatial distribution of on- and off-beta cells was studied from the HRP-labelled material. On-beta cells form a lattice with regular inter-cell spacings ; off-beta cells are also regularly arrayed. The two lattices are superimposed independently of each other. Beta cells are commonly assumed to be associated with the resolution of fine detail in the cat visual system. The mosaic of beta cells imposes some constraints and permits some predictions to be made with respect to the cat’s visual discrimination.

scholarly journals Allocation of the diet of the Argentine Islands’ inshore ichthyofauna

2021 ◽  
Vol 29 (1) ◽  
pp. 67-72
Author(s):  
A. V. Zinkovskyi ◽  
I. V. Dykyy ◽  
V. M. Trokhymets
Keyword(s):  
Dominant Species ◽  
Common Species ◽  
Ecosystem Change ◽  
Hepatosomatic Index ◽  
Fish Diets ◽  
Phenological Changes ◽  
Pagothenia Borchgrevinki ◽  
Notothenia Coriiceps ◽  
Trematomus Bernacchii ◽  
Access To Food

Fish diets are important indicators of ecosystem change. This aspect of the ichthyofauna of the coast of the Argentine Islands has been insufficiently studied in comparison with other regions. This article presents the results of comparison of dietary and somatic parameters of the dominant species Notothenia coriiceps depending on the point, depth and season of catch. The sample was collected between February 2006 and February 2007. In the year of study, N. coriiceps, Trematomus bernacchii, Chaenocephalus aceratus (common species), Harpagifer antarcticus and Pagothenia borchgrevinki (rare species in this region) were caught. The average fish size in this region does not differ from other places in the Southern Ocean. In Cornice Channel and Stella Creek, N. coriiceps was smaller than at other points due to the narrowness and shallow depth of these places. In winter, large individuals apparently migrated from the coast. The diet of N. coriiceps consisted mainly of crustaceans and seaweeds, with a small number of mollusks (especially limpets), which are common. The number of fish in the diet of N. coriiceps is relatively low for this region. Access to food was relatively the same at different points and depths of the catch. The lowest amount of food was in the fall, the highest amount of food was in the spring and summer. The condition and hepatosomatic index also did not change depending on the point and depth of the catch, but they were low in spring and high in summer. Perhaps this is due to the low energy value of food, which is not compensated by the amount. It is necessary to conduct studies of the diet of N. coriiceps in other years to clarify the specificity of fish in the diet and phenological changes in somatic parameters. Similar studies are needed for other species in the region if catches are sufficient to collect a representative sample.

Nonuniform retinal expansion during the formation of the rabbit's visual streak: Implications for the ontogeny of mammalian retinal topography

1989 ◽  
Vol 2 (3) ◽  
pp. 201-219 ◽  
Author(s):  
Stephen R. Robinson ◽  
Bogdan Dreher ◽  
Murray J. McCall
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Density Ratio ◽  
Retinal Ganglion ◽  
Retinal Area ◽  
Small Component ◽  
Retinal Topography ◽  
Visual Streak ◽  
Density Ratios ◽  
Inferior Edge

AbstractWe have studied the distribution of retinal ganglion cells (RGCs) which have been retrogradely labeled from massive bilateral injections of the enzyme horseradish peroxidase into the retino-recipient nuclei of foetal and postnatal albino rabbits aged from the 24th postconceptional day (24PCD) to adulthood. The number of labeled RGCs increases from about 447,000 on the 24PCD to a peak of about 525,000 on the 27PCD. From the 29PCD to birth (31/32PCD), the number of RGCs rapidly declines to about 375,000. During the next 20 d, the number of RGCs stabilizes at about 335,000. After the 51PCD, the number of RGCs gradually declines to the adult value of about 280,000. Retinal area steadily increases from about 40 mm2 on the 24PCD to about 500 mm2 in the adult, while RGC density decreases. However, the reduction in RGC density is nonuniform: RGC density in the visual streak drops from 18,600 RGCs mm2 on the 24PCD to 4700 RGCs/mm2 in the adult, whereas RGC densities at the superior and inferior edges of the retina decrease proportionally much more (from 9300 to 105 RGCs/mm2 and from 12,000 to 170 RGCs/mm2, respectively). As a result of this differential reduction in RGC density, the streak:superior edge RGC density ratio changes from 2.0:1 on the 24PCD to about 45:1 in the adult, while the streak/inferior edge ratio changes from 1.6:1 to about 28:1. In the periods from the 24PCD to the 29PCD and from the 32PCD to adulthood, the proportional increases in the streak/superior edge and streak/inferior edge RGC density ratios are linearly related to the proportional increases in retinal area. However, between the 29PCD and 32PCD, the RGC density ratios increase at a greater rate than retinal area. We conclude that (1) the centro-peripheral difference in RGC density that is already present on the 24PCD might be attributable to differential RGC generation; (2) the redistribution of RGCs between the 24PCD and adulthood is mainly due to nonuniform expansion of the retina, with minimal expansion of the visual streak and maximal expansion at the superior and inferior retinal edges; and (3) a small component of the increase in the centro-peripheral RGC density ratio, which becomes apparent between the 29PCD and 32PCD, is probably due to differential RGC loss. We discuss the pattern of retinal expansion in the rabbit and the factors which might contribute to it.

scholarly journals Warming, not CO2-acidified seawater, alters otolith development of juvenile Antarctic emerald rockcod (Trematomus bernacchii)

Polar Biology ◽  
2021 ◽  
Author(s):  
Andrew W. Naslund ◽  
Brittany E. Davis ◽  
James A. Hobbs ◽  
Nann A. Fangue ◽  
Anne E. Todgham
Keyword(s):  
Fossil Fuels ◽  
Marine Species ◽  
Ocean Warming ◽  
Antarctic Species ◽  
Antarctic Fishes ◽  
Polar Species ◽  
Physiological Limits ◽  
Length Width ◽  
Trematomus Bernacchii ◽  
Projected Changes

AbstractThe combustion of fossil fuels is currently causing rapid rates of ocean warming and acidification worldwide. Projected changes in these parameters have been repeatedly observed to stress the physiological limits and plasticity of many marine species from the molecular to organismal levels. High latitude oceans are among the fastest changing ecosystems; therefore, polar species are projected to be some of the most vulnerable to climate change. Antarctic species are particularly sensitive to environmental change, having evolved for millions of years under stable ocean conditions. Otoliths, calcified structures found in a fish’s inner ear used to sense movement and direction, have been shown to be affected by both warming and CO2-acidified seawater in temperate and tropical fishes but there is no work to date on Antarctic fishes. In this study, juvenile emerald rockcod (Trematomus bernacchii) were exposed to projected seawater warming and CO2-acidification for the year 2100 over 28 days. Sagittal otoliths were analyzed for changes in area, perimeter, length, width and shape. We found ocean warming increased the growth rate of otoliths, while CO2-acidified seawater and the interaction of warming and acidification did not have an effect on otolith development. Elevated temperature also altered the shape of otoliths. If otolith development is altered under future warming scenarios, sensory functions such as hearing, orientation, and movement may potentially be impaired. Changes in these basic somatic abilities could have broad implications for the general capabilities and ecology of early life stages of Antarctic fishes.

Representation of the temporal raphe within the optic tract of the cat

1989 ◽  
Vol 2 (3) ◽  
pp. 255-267 ◽  
Author(s):  
T. Fitzgibbon ◽  
W. Burke
Keyword(s):  
Optic Disc ◽  
Ganglion Cells ◽  
Optic Tract ◽  
Cell Labeling ◽  
Venn Diagram ◽  
Retinal Ganglion ◽  
Retinal Topography ◽  
Area Centralis ◽  
Diagram Analysis ◽  
Lateral Tract

AbstractThe retinal topography of the cat's optic tract was determined by means of injections of the enzyme horseradish peroxidase (HRP) into the tract. This analysis was accomplished by the subtraction of all HRP injection sites not labeling a defined retinal area from those injection sites which resulted in ganglion cell labeling (Venn diagram analysis). Using this method, the following correspondences were demonstrated for the ipsilateral and contralateral projections: superior retina represented in medial optic tract; inferior retina in lateral tract; and area centralis in a dorsocentral location (which was part of a larger area representing the visual streak). The temporal raphe was represented in the ipsilateral tract as a band curving from the area centralis region toward the dorsomedial border of the tract. Contralateral fibers from a region superior to the optic disc were found to be displaced with respect to the general retinal representation in the optic tract and this appeared to be related to retinal development. The ratio of contralateral to ipsilateral fibers was determined and found to be nonuniform within the tract.Injection of HRP into the optic tract of the cat also allowed the axons from labeled retinal ganglion cells to be traced within the retina and optic disc. Axons from ganglion cells lying temporal to the raphe curve around the area centralis enter the optic disc on the lateral and inferior aspects. Ganglion cells lying nasal to the raphe send their axons more directly to enter the optic disc on its superior aspect. A schema is proposed whereby the retina is mapped onto the optic tract.

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