Bioelectric Fields in Sea Water and the Function of the Ampullae of Lorenzini in Elasmobranch Fishes

Description of the mechanoreceptive lateral line and electroreceptive ampullary systems in the freshwater whipray, Himantura dalyensis

Marine and Freshwater Research ◽

10.1071/mf10156 ◽

2011 ◽

Vol 62 (6) ◽

pp. 771 ◽

Cited By ~ 12

Author(s):

Teagan A. Marzullo ◽

Barbara E. Wueringer ◽

Lyle Squire Jnr ◽

Shaun P. Collin

Keyword(s):

Lateral Line ◽

Related Species ◽

Sensory Systems ◽

Low Salinity ◽

Dasyatis Sabina ◽

Estuarine Species ◽

Ampullae Of Lorenzini ◽

Infraorbital Canal ◽

Elasmobranch Species ◽

Elasmobranch Fishes

Mechanoreceptive and electroreceptive anatomical specialisations in freshwater elasmobranch fishes are largely unknown. The freshwater whipray, Himantura dalyensis, is one of a few Australian elasmobranch species that occur in low salinity (oligohaline) environments. The distribution and morphology of the mechanoreceptive lateral line and the electroreceptive ampullae of Lorenzini were investigated by dissection and compared with previous studies on related species. The distribution of the pit organs resembles that of a marine ray, Dasyatis sabina, although their orientation differs. The lateral line canals of H. dalyensis are distributed similarly compared with two marine relatives, H. gerrardi and D. sabina. However, convolutions of the ventral canals and proliferations of the infraorbital canal are more extensive in H. dalyensis than H. gerrardi. The intricate nature of the ventral, non-pored canals suggests a mechanotactile function, as previously demonstrated in D. sabina. The ampullary system of H. dalyensis is not typical of an obligate freshwater elasmobranch (i.e. H. signifer), and its morphology and pore distribution resembles those of marine dasyatids. These results suggest that H. dalyensis is euryhaline, with sensory systems adapted similarly to those described in marine and estuarine species.

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Immunochemical analysis of the vacuolar proton-ATPase B-subunit in the gills of a euryhaline stingray (Dasyatis sabina): effects of salinity and relation to Na+/K+-ATPase

Journal of Experimental Biology ◽

10.1242/jeb.204.19.3251 ◽

2001 ◽

Vol 204 (19) ◽

pp. 3251-3259 ◽

Cited By ~ 18

Author(s):

Peter M. Piermarini ◽

David H. Evans

Keyword(s):

Sea Water ◽

Basolateral Membrane ◽

Teleost Fishes ◽

Pavement Cells ◽

B Subunit ◽

Dasyatis Sabina ◽

Proton Atpase ◽

Elasmobranch Fishes ◽

Atpase Localization ◽

Na Uptake

SUMMARY In the gills of freshwater teleost fishes, vacuolar proton-ATPase (V-H+-ATPase) is found on the apical membrane of pavement and chloride (Na+/K+-ATPase-rich) cells, and is an important transporter for energizing Na+ uptake and H+ excretion. In the gills of elasmobranch fishes, the V-H+-ATPase has not been extensively studied and its expression in freshwater individuals has not been examined. The goals of this study were to examine the effects of environmental salinity on the expression of V-H+-ATPase in the gills of an elasmobranch (the Atlantic stingray, Dasyatis sabina) and determine if V-H+-ATPase and Na+/K+-ATPase are expressed in the same cells. We found that gills from freshwater stingrays had the highest relative abundance of V-H+-ATPase and greatest number of V-H+-ATPase-rich cells, using immunoblotting and immunohistochemistry, respectively. When freshwater animals were acclimated to sea water for 1 week, V-H+-ATPase abundance and the number of V-H+-ATPase-rich cells decreased significantly. Atlantic stingrays from seawater environments were characterized by the lowest expression of V-H+-ATPase and least number of V-H+-ATPase-rich cells. In contrast to teleost fishes, localization of V-H+-ATPase in freshwater stingray gills was not found in pavement cells and occurred on the basolateral membrane in cells that are presumably rich in mitochondria. In freshwater stingrays acclimated to sea water and seawater stingrays, V-H+-ATPase localization appeared qualitatively to be stronger in the cytoplasm, which may suggest the transporter was stored in vesicles. Using a double-immunolabeling technique, we found that V-H+-ATPase and Na+/K+-ATPase occurred in distinct cells, which suggests there may be two types of mitochondrion-rich cells in the elasmobranch gill epithelium. Based on these findings, we propose a unique model of NaCl and acid–base regulation where the V-H+-ATPase-rich cells and Na+/K+-ATPase-rich cells are the sites of Cl– uptake/HCO3– excretion and Na+ uptake/H+ excretion, respectively.

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The Electric Sense of Sharks and Rays

Journal of Experimental Biology ◽

10.1242/jeb.55.2.371 ◽

1971 ◽

Vol 55 (2) ◽

pp. 371-383 ◽

Cited By ~ 12

Author(s):

A. J. KALMIJN

Keyword(s):

Electric Fields ◽

Thin Sheet ◽

Plastic Film ◽

Mechanical Stimuli ◽

Crucial Experiment ◽

Visual Contact ◽

Scyliorhinus Canicula ◽

Ampullae Of Lorenzini ◽

Raja Clavata ◽

Bioelectric Fields

1. Previous experiments have demonstrated that (a) the shark Scyliorhinus canicula and the ray Raja clavata are extremely sensitive to weak electric fields; (b) their electrical sensitivity is due to the ampullae of Lorenzini; (c) the sharks and rays can be stimulated by the bioelectric fields emanating from the flatfish Pleuronectes platessa. 2. When hungry, Scyliorhinus and Raja perform well-aimed feeding responses to flatfish, even if the prey have covered themselves with sand. The object of the present study was to determine whether the sharks and rays use the bioelectric fields of the flatfish to detect the position of their prey. 3. To analyse the feeding responses of the sharks and rays, a flatfish was put into an agar chamber. The predators responded to the so screened prey from the same distance, and tried to feed on it in the same way as if there were no agar at all. As the flatfish in the agar chamber was completely hidden from view, the sharks and rays were thus shown not to need visual contact to locate the prey. 4. If the agar chamber was filled with cut-up pieces of whiting, the sharks and rays did not respond to the food, although the odour of whiting juice normally attracts them strongly. Therefore, the sharks and rays did not detect the position of the agarscreened flatfish by smell. 5. The feeding responses to the flatfish could be entirely abolished by covering the agar chamber with a very thin sheet of plastic. The mechanical attenuation offered by the plastic film was too weak to explain its dramatic inhibitory effect, and, thus, a purely mechanical detection of the agar-screened flatfish without plastic film was also ruled out. 6. As the responses to the agar-screened flatfish were not merely due to visual, chemical, or mechanical stimuli, it was tentatively concluded that the sharks and rays perceived the prey electrically. This conclusion was fully in agreement with the results of the experiments, for the agar chamber did not appreciably distort the bioelectric fields of the flatfish, and the electrical impedance of the plastic film was extremely high. 7. Further, the bioelectric field of a flatfish was simulated with a pair of electrodes, buried in the sand. Now, the sharks and rays displayed exactly the same feeding responses to the electrodes as they did previously to the real prey. This crucial experiment confirmed the electrical hypothesis in a very direct way. 8. The experiments described demonstrate clearly that the shark Scyliorhinus canicula and the ray Raja clavata make a biologically significant use of their electrical sensitivity. Therefore, we now are justified in accrediting the animals with an electric sense and in designating the ampullae of Lorenzini as electroreceptors. 9. When the sharks and rays were offered a piece of whiting in the vicinity of two electrodes simulating a flatfish, they were attracted by the odour of the food but usually performed their well-aimed responses to the electrodes. Thus, at short range, the electric fields act as a much stronger directive force than do the visual and chemical stimuli. Only direct mechanical contact dominates over the electrical stimuli. 10. Theoretically, the sharks and rays can detect the electric fields resulting from ceanic and tidal currents. Whether they make use of the available information for orientation in the open sea is not yet known. Furthermore, the observations and measurements described indicate that, in studying shark attacks, the electric fields of the prey and the electric sense of the predators should be taken into account.

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