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Electrosensitive spatial vectors in elasmobranch fishes: implications for source localization.

Rivera-Vicente AC, Sewell J, Tricas TC - PLoS ONE (2011)

Bottom Line: The MAN canals of all species project in anterior or posterior directions behind the mouth and likely coordinate prey capture.Vertical elevation was greatest in the BUC of the sandbar shark, restricted by the hammerhead cephalofoil and extremely limited in the dorsoventrally flattened stingray.These results are consistent with the functional subunit hypothesis that predicts specialized ampullary functions for processing of weak dipole and geomagnetic induced fields, and provides an anatomical basis for future experiments on central processing of different forms of relevant electric stimuli.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.

ABSTRACT
The electrosense of sharks and rays is used to detect weak dipole-like bioelectric fields of prey, mates and predators, and several models propose a use for the detection of streaming ocean currents and swimming-induced fields for geomagnetic orientation. We assessed pore distributions, canal vectors, complementarity and possible evolutionary divergent functions for ampullary clusters in two sharks, the scalloped hammerhead (Sphyrna lewini) and the sandbar shark (Carcharhinus plumbeus), and the brown stingray (Dasyatis lata). Canal projections were determined from measured coordinates of each electrosensory pore and corresponding ampulla relative to the body axis. These species share three ampullary groups: the buccal (BUC), mandibular (MAN) and superficial ophthalmic (SO), which is subdivided into anterior (SOa) and posterior (SOp) in sharks. The stingray also has a hyoid (HYO) cluster. The SOp in both sharks contains the longest (most sensitive) canals with main projections in the posterior-lateral quadrants of the horizontal plane. In contrast, stingray SO canals are few and short with the posterior-lateral projections subsumed by the HYO. There was strong projection coincidence by BUC and SOp canals in the posterior lateral quadrant of the hammerhead shark, and laterally among the stingray BUC and HYO. The shark SOa and stingray SO and BUC contain short canals located anterior to the mouth for detection of prey at close distance. The MAN canals of all species project in anterior or posterior directions behind the mouth and likely coordinate prey capture. Vertical elevation was greatest in the BUC of the sandbar shark, restricted by the hammerhead cephalofoil and extremely limited in the dorsoventrally flattened stingray. These results are consistent with the functional subunit hypothesis that predicts specialized ampullary functions for processing of weak dipole and geomagnetic induced fields, and provides an anatomical basis for future experiments on central processing of different forms of relevant electric stimuli.

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Horizontal view of the electrosensory arrays of the sandbar shark, Carcharhinus plumbeus.(A), scalloped hammerhead shark, Sphyrna lewini (B) and brown stingray, Dasyatis lata (C). Canals with pores on the dorsal and ventral surface are shown on the left and right side of the figure, respectively. Canals from each ampullary group are represented by different colors (BUC  =  blue, SOa  =  green, SOp  =  red, HYO  =  pink). Location of ampullae are indicated by black dots at the base of canals.
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pone-0016008-g002: Horizontal view of the electrosensory arrays of the sandbar shark, Carcharhinus plumbeus.(A), scalloped hammerhead shark, Sphyrna lewini (B) and brown stingray, Dasyatis lata (C). Canals with pores on the dorsal and ventral surface are shown on the left and right side of the figure, respectively. Canals from each ampullary group are represented by different colors (BUC  =  blue, SOa  =  green, SOp  =  red, HYO  =  pink). Location of ampullae are indicated by black dots at the base of canals.

Mentions: The electrosensory ampullae on the left side of the head in the hammerhead and sandbar sharks were classified into three clusters that followed the branch of the associated anterior lateral line nerve: the buccal (BUC), superficial ophthalmic (SO) and mandibular (MAN). The SO nerve further divides into branches that innervate the physically distinct superficial ophthalmic anterior (SOa) and superficial ophthalmic posterior (SOp) sub-clusters (Fig. 2A, 2B). In the stingray, four distinct clusters are present: the BUC, the hyoid (HYO), the SO, and the MAN (Fig. 2C). In all species, the MAN cluster only projects to the ventral surface, whereas all other ampullary clusters had canal projections to both the dorsal and ventral surfaces of the head.


Electrosensitive spatial vectors in elasmobranch fishes: implications for source localization.

Rivera-Vicente AC, Sewell J, Tricas TC - PLoS ONE (2011)

Horizontal view of the electrosensory arrays of the sandbar shark, Carcharhinus plumbeus.(A), scalloped hammerhead shark, Sphyrna lewini (B) and brown stingray, Dasyatis lata (C). Canals with pores on the dorsal and ventral surface are shown on the left and right side of the figure, respectively. Canals from each ampullary group are represented by different colors (BUC  =  blue, SOa  =  green, SOp  =  red, HYO  =  pink). Location of ampullae are indicated by black dots at the base of canals.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3020962&req=5

pone-0016008-g002: Horizontal view of the electrosensory arrays of the sandbar shark, Carcharhinus plumbeus.(A), scalloped hammerhead shark, Sphyrna lewini (B) and brown stingray, Dasyatis lata (C). Canals with pores on the dorsal and ventral surface are shown on the left and right side of the figure, respectively. Canals from each ampullary group are represented by different colors (BUC  =  blue, SOa  =  green, SOp  =  red, HYO  =  pink). Location of ampullae are indicated by black dots at the base of canals.
Mentions: The electrosensory ampullae on the left side of the head in the hammerhead and sandbar sharks were classified into three clusters that followed the branch of the associated anterior lateral line nerve: the buccal (BUC), superficial ophthalmic (SO) and mandibular (MAN). The SO nerve further divides into branches that innervate the physically distinct superficial ophthalmic anterior (SOa) and superficial ophthalmic posterior (SOp) sub-clusters (Fig. 2A, 2B). In the stingray, four distinct clusters are present: the BUC, the hyoid (HYO), the SO, and the MAN (Fig. 2C). In all species, the MAN cluster only projects to the ventral surface, whereas all other ampullary clusters had canal projections to both the dorsal and ventral surfaces of the head.

Bottom Line: The MAN canals of all species project in anterior or posterior directions behind the mouth and likely coordinate prey capture.Vertical elevation was greatest in the BUC of the sandbar shark, restricted by the hammerhead cephalofoil and extremely limited in the dorsoventrally flattened stingray.These results are consistent with the functional subunit hypothesis that predicts specialized ampullary functions for processing of weak dipole and geomagnetic induced fields, and provides an anatomical basis for future experiments on central processing of different forms of relevant electric stimuli.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.

ABSTRACT
The electrosense of sharks and rays is used to detect weak dipole-like bioelectric fields of prey, mates and predators, and several models propose a use for the detection of streaming ocean currents and swimming-induced fields for geomagnetic orientation. We assessed pore distributions, canal vectors, complementarity and possible evolutionary divergent functions for ampullary clusters in two sharks, the scalloped hammerhead (Sphyrna lewini) and the sandbar shark (Carcharhinus plumbeus), and the brown stingray (Dasyatis lata). Canal projections were determined from measured coordinates of each electrosensory pore and corresponding ampulla relative to the body axis. These species share three ampullary groups: the buccal (BUC), mandibular (MAN) and superficial ophthalmic (SO), which is subdivided into anterior (SOa) and posterior (SOp) in sharks. The stingray also has a hyoid (HYO) cluster. The SOp in both sharks contains the longest (most sensitive) canals with main projections in the posterior-lateral quadrants of the horizontal plane. In contrast, stingray SO canals are few and short with the posterior-lateral projections subsumed by the HYO. There was strong projection coincidence by BUC and SOp canals in the posterior lateral quadrant of the hammerhead shark, and laterally among the stingray BUC and HYO. The shark SOa and stingray SO and BUC contain short canals located anterior to the mouth for detection of prey at close distance. The MAN canals of all species project in anterior or posterior directions behind the mouth and likely coordinate prey capture. Vertical elevation was greatest in the BUC of the sandbar shark, restricted by the hammerhead cephalofoil and extremely limited in the dorsoventrally flattened stingray. These results are consistent with the functional subunit hypothesis that predicts specialized ampullary functions for processing of weak dipole and geomagnetic induced fields, and provides an anatomical basis for future experiments on central processing of different forms of relevant electric stimuli.

Show MeSH