Retinal specializations and visual ecology in an animal with an extremely elaborate pupil shape: the little skate Leucoraja (Raja) erinacea Mitchell, 1825

2018 ◽  
Vol 526 (12) ◽  
pp. 1962-1977 ◽  
Author(s):  
S. Terrell Jinson ◽  
Jan Liebich ◽  
Stephen L. Senft ◽  
Lydia M. Mäthger
Keyword(s):  
Visual Ecology ◽  
Raja Erinacea

Visual Ecology

2015 ◽  
Vol 48 (3) ◽  
pp. 221-223 ◽  
Author(s):  
Martin Stevens
Keyword(s):  
Visual Ecology

Cupula Motion in the Semicircular Canal of the Skate,RAJA ERINACEA An Experimental Investigation

1979 ◽  
Vol 87 (3-6) ◽  
pp. 528-538 ◽  
Author(s):  
Charles M. Oman ◽  
Lawrence S. Frishkopf ◽  
Moise H. Goldstein
Keyword(s):  
Experimental Investigation ◽  
Semicircular Canal ◽  
Raja Erinacea

Motor corollary discharge activity and sensory responses related to ventilation in the skate vestibulolateral cerebellum: implications for electrosensory processing

1996 ◽  
Vol 199 (3) ◽  
pp. 673-681 ◽  
Author(s):  
G Hjelmstad ◽  
G Parks ◽  
D Bodznick
Keyword(s):  
Noise Cancellation ◽  
Second Order ◽  
Corollary Discharge ◽  
Parallel Fiber ◽  
Large Percentage ◽  
Principal Function ◽  
Raja Erinacea ◽  
Dorsal Nucleus ◽  
Sensory Responses ◽  
Electrosensory Processing

The dorsal granular ridge (DGR) of the elasmobranch vestibulolateral cerebellum is the source of a parallel fiber projection to the electrosensory dorsal nucleus. We report that the DGR in Raja erinacea contains a large percentage of units with activity modulated by the animal's own ventilation. These include propriosensory and electrosensory units, responding to either ventilatory movements or the resulting electroreceptive reafference, and an additional population of units in which activity is phase-locked to the ventilatory motor commands even in animals paralyzed to block all ventilatory movements. A principal function of processing in the dorsal nucleus is the elimination of ventilatory noise in second-order electrosensory neurons. The existence of these ventilatory motor corollary discharge units, along with other DGR units responsive to ventilatory movements, suggests that the parallel fiber projection is involved in the noise cancellation mechanisms.

scholarly journals NOTES ON THE ATROPHY OF THE EYE OF RAJA ERINACEA

Science ◽  
1908 ◽  
Vol 28 (730) ◽  
pp. 930-931
Author(s):  
W. M. Smallwood
Keyword(s):  
Raja Erinacea

Carrier-mediated urea transport across the mitochondrial membrane of an elasmobranch (Raja erinacea) and a teleost (Oncorhynchus mykiss) fish

2008 ◽  
Vol 294 (6) ◽  
pp. R1947-R1957 ◽  
Author(s):  
T. M. Rodela ◽  
J. S. Ballantyne ◽  
P. A. Wright
Keyword(s):  
Oncorhynchus Mykiss ◽  
Mitochondrial Membrane ◽  
Liver Mitochondria ◽  
Reverse Direction ◽  
Maximal Velocity ◽  
Urea Transport ◽  
Submitochondrial Particles ◽  
Raja Erinacea ◽  
Urea Uptake ◽  
High Concentrations

In osmoregulating teleost fish, urea is a minor nitrogen excretory product, whereas in osmoconforming marine elasmobranchs it serves as the major tissue organic solute and is retained at relatively high concentrations (∼400 mmol/l). We tested the hypothesis that urea transport across liver mitochondria is carrier mediated in both teleost and elasmobranch fishes. Intact liver mitochondria in rainbow trout ( Oncorhynchus mykiss) demonstrated two components of urea uptake, a linear component at high concentrations and a phloretin-sensitive saturable component [Michaelis constant ( Km) = 0.58 mmol/l; maximal velocity ( Vmax) = 0.12 μmol·h−1·mg protein−1] at lower urea concentrations (<5 mmol/l). Similarly, analysis of urea uptake in mitochondria from the little skate ( Raja erinacea) revealed a phloretin-sensitive saturable transport ( Km= 0.34 mmol/l; Vmax= 0.054 μmol·h−1·mg protein−1) at low urea concentrations (<5 mmol/l). Surprisingly, urea transport in skate, but not trout, was sensitive to a variety of classic ionophores and respiration inhibitors, suggesting cation sensitivity. Hence, urea transport was measured in the reverse direction using submitochondrial particles in skate. Transport kinetics, inhibitor response, and pH sensitivity were very similar in skate submitochondrial particle submitochondrial particles ( Km= 0.65 mmol/l, Vmax= 0.058 μmol·h−1·mg protein−1) relative to intact mitochondria. We conclude that urea influx and efflux in skate mitochondria is dependent, in part, on a bidirectional proton-sensitive mechanism similar to bacterial urea transporters and reminiscent of their ancestral origins. Rapid equilibration of urea across the mitochondrial membrane may be vital for cell osmoregulation (elasmobranch) or nitrogen waste excretion (teleost).

scholarly journals Colourfulness as a possible measure of object proximity in the larval zebrafish brain

2020 ◽  
Author(s):  
Philipp Bartel ◽  
Filip K Janiak ◽  
Daniel Osorio ◽  
Tom Baden
Keyword(s):  
Dynamic Range ◽  
Red Light ◽  
Visible Spectrum ◽  
Visual Ecology ◽  
Neural Representation ◽  
Spectral Tuning ◽  
Fish Brain ◽  
Visual Neurons ◽  
Zebrafish Brain ◽  
Larval Zebrafish

The encoding of light increments and decrements by separate On- and Off- systems is a fundamental ingredient of vision, which supports the detection of edges in space and time and makes efficient use of limited dynamic range of visual neurons [1]. Theory predicts that the neural representation of On- and Off-signals should be approximately balanced, including across an animals’ full visible spectrum. Here we find that larval zebrafish violate this textbook expectation: in the fish brain, UV-stimulation near exclusively gives On-responses, blue/green-stimulation mostly Off- responses, and red-light alone elicits approximately balanced On- and Off-responses (see also [2–4]). We link these findings to zebrafish visual ecology, and suggest that the observed spectral tuning boosts the encoding of object “colourfulness”, which correlates with object proximity in their underwater world [5].

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