Guanine-type retinal tapetum and ganglion cell topography in the retina of a carangid fish,Kaiwarinus equula

Takei, Shiro; Somiya, Hiroaki

doi:10.1098/rspb.2001.1849

Cited by 12 publications

(10 citation statements)

References 33 publications

(33 reference statements)

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“…The same tapetum characteristics have been observed in other deep-sea sharks such as Etmopterus virens (Gilbert, 1963) and Galeus melastomus (Bozzano et al 2001). Recent analysis by Takei and Somiya (2002) of the tapetum and visual threshold in fish indicates that fish with tapeta could prey in a more extended space.…”

Section: Discussionsupporting

confidence: 48%

Retinal specialisations in the dogfish Centroscymnus coelolepis from the Mediterranean deep-sea

Bozzano¹

2004

Sci. Mar.

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SUMMARY: The present work attempted to study the importance of vision in Centroscymnus coelolepis, the most abundant shark in the Mediterranean beyond a depth of 1000 m, by using anatomical and histological data. C. coelolepis exhibited large lateral eyes with a large pupil, spherical lens and a tapetum lucidum that gave the eye a strong greenish-golden "eye shine". In the outer retinal layer, a uniform population of rod-like photoreceptors was observed while in the vitreal retina a thick inner plexiform layer comprised up to 30% of the whole retinal thickness. The cell distribution of the ganglion cell layer formed a thin elongated visual streak in the central plane of the eye that provided a horizontal panoramic field of view. A specialised area of higher visual acuity was located caudally at 32-44º from the geometric centre of the retina and 5-10º above the horizontal plane of the eye. This position indicated that the visual axis pointed in a slightly outward-forward direction with respect to the fish body axis. A non-uniform distribution of large ganglion cells was also found in the horizontal plane of the retina that practically coincided with the distribution of the total cell population in the ganglion cell layer. This is the first time that this type of retinal specialisation has been observed in the elasmobranchs. These characteristics indicate that the retina of C. coelolepis is designed not only to increase sensitivity in the horizontal field of view, as was also observed in other sharks, but also to improve motion detection in the same plane. The visual capacities evolved by C. coelolepis make this species adapted for discriminating the horizontal gradation of light that exists in the mesopelagic environment. Similarly, the large ganglion cell distribution observed in its retina seems to be related to its predatory behaviour, since it allows this shark to perceive the movement of bioluminescent prey against a totally dark background.Key words: deep-sea shark, retinal morphology, retinal topography, large ganglion cells, visual axes, diet. RESUMEN: ESPECIALIZACIONES EN LA RETINA DEL TIBURÓN CENTROSCYMNUS COELOLEPIS DEL MEDITERRÁNEO PROFUNDO. -El presente trabajo estudia la importancia de la visión en Centroscymnus coelolepis, el tiburón más abundante en el Mediterráneo por debajo de los 1000 m de profundidad, usando datos anatómicos e histológicos. C. coelolepis posee grandes ojos laterales, una pupila muy ancha, un cristalino esférico y un tapetum lucidum que confiere al ojo un fuerte brillo verde-dorado. En la capa externa de la retina, se observa una población uniforme de fotorreceptores parecidos a los bastones, mientras en la capa interna el estrato plexiforme interno es grueso, ocupando hasta el 30% del entero grosor de la retina. La distribución de las células en la capa ganglionar forma una sutil franja horizontal alargada en correspondencia del plano central del ojo que permite al animal una visión panorámica horizontal. Caudalmente se localizó una área especializada de mejor agudeza visual a...

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Section: Discussionsupporting

confidence: 48%

Retinal specialisations in the dogfish Centroscymnus coelolepis from the Mediterranean deep-sea

Bozzano¹

2004

Sci. Mar.

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“…1) indicate that prey items are preferentially taken from below. In contrast, in benthic fish such as Kaiwarinus equula the area centralis and locus tapetalis do not cooccur (Takei and Somiya, 2002), because the region of most acute vision lies in front of the fish (not above) and high photosensitivity is directed downward (Fig. 5).…”

Section: Discussionmentioning

confidence: 83%

“…The sensitivity increase thus gained amounts to a factor of 1.5 (Takei and Somiya, 2002), such being thought to assist fishes to perceive objects under dim ambient light conditions (Denton, 1970;Locket, 1977;Somiya, 1980;Nicol, 1989;Douglas et al, 1998;Somiya et al, 2000;Takei and Somiya, 2002). To the best of our knowledge, no tapetum of any kind has been previously described from a bramid fish.…”

Section: Ichthyological Researchmentioning

confidence: 88%

Guanine-type retinal tapetum in the eye of the Pacific pomfret Brama japonica (Perciformes: Bramidae)

Takei

Momose

Nakamura

et al. 2003

Ichthyological Research

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The eye of Brama japonica, which exhibits eyeshine, contains a retinal tapetum composed of guanine. The total amounts of guanine in the eyes of two specimens measuring 19.5 and 51.4 cm in standard length were 7.4 and 70.5 mg, respectively, the respective retinal surface areas being 4.9 and 39.9 cm 2 . The mean guanine content was almost identical (1.5 and 1.8 mg/cm 2 , respectively). A locus tapetalis, with guanine values exceeding 2.5 mg/cm 2 , was developed in the ventrotemporal region of the retina, where it cooccurred with the area centralis. Evidence is presented that sound functional reasons exist for both the development of the locus tapetalis and its position in the retina. A plea is made for future examination of the retinae of additional pelagic and nonpelagic species for the presence and location of a locus tapetalis.

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“…These features define the position of blind spots and the influences of a vascular blood supply on acute vision. 9 Topographic differences in the concentration of reflective structures (tapetal material) underlying the retina, which can be used as an indicator of retinal regions of enhanced sensitivity in species occupying low light environments [Ollivier et al, 2004;Somiya, 1980;Takei and Somiya, 2002]. 10 Peak spectral sensitivities of multiple photoreceptors arranged into two-dimensional arrays simultaneously [Levine et al, 1979].…”

mentioning

confidence: 99%

The Retinal Wholemount Technique: A Window to Understanding the Brain and Behaviour

et al. 2011

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The accessibility of the vertebrate retina has provided the opportunity to assess various parameters of the visual abilities of a range of species. This thin but complex extension of the brain achieves a large proportion of the necessary visual processing of an optical image before information is delivered to the brain as neural impulses. Studies of the retina as a wholemount or a flattened sheet of neural tissue are abundant due to the large amount of information that can be analysed, as follows: the level of summation or convergence; the coverage, stratification and potential sites of synaptic connections; the spatial resolving power; the arrangement of neuronal arrays or mosaics; electrophysiological access for the recording of responses to visual stimuli; the spatial arrangement of cell dendritic fields; location of retinal ‘blind spots’ (optic nerve, falciform process and pecten); topographic differences in retinal cell sampling; spectral filters, and reflective structures. The present study examines all aspects of the wholemount technique, including enucleation, fixation, retinal extraction, flattening, staining, visualization of labelled cells and stereological mapping of cell density. Uniquely, it highlights the crucial technical and often species-specific differences encountered when examining a range of vertebrate taxa (fishes, reptiles, birds and mammals). This broad comparative approach will enable future studies to overcome technical difficulties, thus permitting larger conceptual questions to be posed regarding the diversity of visual tasks across phylogenetic boundaries.

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Guanine-type retinal tapetum and ganglion cell topography in the retina of a carangid fish,Kaiwarinus equula

Cited by 12 publications

References 33 publications

Retinal specialisations in the dogfish <i>Centroscymnus coelolepis</i> from the Mediterranean deep-sea

Retinal specialisations in the dogfish <i>Centroscymnus coelolepis</i> from the Mediterranean deep-sea

Guanine-type retinal tapetum in the eye of the Pacific pomfret Brama japonica (Perciformes: Bramidae)

The Retinal Wholemount Technique: A Window to Understanding the Brain and Behaviour

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