The distribution and density of the ampullary electroreceptors in the skin of elasmobranchs are influenced by the phylogeny and ecology of a species. Sensory maps were created for 4 species of pristid sawfish. Their ampullary pores were separated into pore fields based on their innervation and cluster formation. Ventrally, ampullary pores are located in 6 areas (5 in Pristis microdon), covering the rostrum and head to the gills. Dorsally, pores are located in 4 areas (3 in P. microdon), which cover the rostrum, head and may extend slightly onto the pectoral fins. In all species, the highest number of pores is found on the dorsal and ventral sides of the rostrum. The high densities of pores along the rostrum combined with the low densities around the mouth could indicate that sawfish use their rostrum to stun their prey before ingesting it, but this hypothesis remains to be tested. The directions of ampullary canals on the ventral side of the rostrum are species specific. P. microdon possesses the highest number of ampullary pores, which indicates that amongst the study species this species is an electroreception specialist. As such, juvenile P. microdon inhabit low-visibility freshwater habitats.

Keywords:
Electroreception, Pristidae, Sawfish, Rostrum, Ampullae of Lorenzini
1.
Andres KH, von Düring M (1998): Comparative anatomy of vertebrate electroreceptors. Prog Brain Res 74:113–131.
2.
Bennett MVL, Clusin WT (1978): Physiology of the ampullae of Lorenzini, the electroreceptor of elasmobranchs; in Hodgson ES, Mathewson RF (eds): Sensory Biology of Sharks, Skates and Rays. Arlington, Department of the Navy, Office of Naval Research, pp 483–506.
3.
Breder CM (1952): On the utility of the saw of the sawfish. Copeia 2:90–91.
4.
Cappetta H (1974): Sclerorhynchidae nov. fam., Pristidae et Pristiophoridae: un exemple de parallélisme chez les Sélaciens. C R Acad Sci Paris Series D 278:225–228.
5.
Cappetta H (1987): Chondrichthyes II: mesozoic and cenozoic elasmobranchii; in Schultze H-P, Kuhn O (eds): Handbook of Paleoichthyology.Munich, Verlag Dr. Friedrich Pfeil, vol 3B p 193.
6.
Chu YT, Wen MC (1979): A study of the lateral-line canal system and that of the Lorenzini ampullae and tubules of elasmobranchiate fishes of China. Monograph of Fishes of China. 2. Shanghai, Academic Press, p 132.
7.
Compagno LJV (1999a): Systematics and body form; in Hamlett WC (ed): Sharks, Skates and Rays. The Biology of Elasmobranch Fishes. Baltimore, John Hopkins University Press, pp 1–42.
8.
Compagno LJV (1999b): Endoskeleton; in Hamlett WC (ed): Sharks, Skates and Rays. The Biology of Elasmobranch Fishes. Baltimore, John Hopkins University Press, pp 69–92.
9.
Compagno LJV, Cook SF (1995): The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future. J Aquaric Aquat Sci 7:62–90.
10.
Compagno LJV, Last PR (1999): Order Pristiformes; in Carpenter KE, Niem VH (eds): The Living Marine Resources of the Western Central Pacific, vol 3: Batoid Fishes, Chimaeras and Bony Fishes. 1. Elopidae to Linophyroidae. Rome, FAO, pp 1397–2068.
11.
Herman J, Hovestadt-Euler M, Hovestadt DC, Stehmann M (1997): Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living supra-specific taxa of Chondrichthyan fishes. Part B. Batomorphii. No. 2: Order: Rajiformes – suborder: Pristoidei – family: Pristidae – genera: Anoxypristis and Pristis. No. 3: Suborder: Rajoidei – superfamily Rhinobatoidea – families: Rhinidae – genera: Rhina and Rhynchobatus and Rhinobatidae – genera: Aptychotrema, Platyrhina, Platyrhinoidis, Rhinobatos, Trygonorrhina, Zanobatus and Zapteryx. Bull Inst R Sci Nat Belg Biol 67:107–162.
12.
Hoffmann L (1912): Zur Kenntnis des Neurocraniums der Pristiden und Pristiophoriden. Zool Jahrb 33:239–360.
13.
Hussakof L (1912): Note on an embryo of Pristis cuspidatus. Bull Am Mus Nat Hist 31:327–330.
14.
Irvine FR (1947): The Fishes and Fisheries of the Gold Coast. London, Crown Agents for the Colonies.
15.
Ishihara H, Taniuchi T, Mitsuhiko S, Last PR (1991): Record of Pristis clavata Garman from the Pentecost River, Western Australia, with brief notes on its osmoregulation and comments on the systematics of Pristidae; in Shimizu M, Taniuchi T (eds): Studies on Elasmobranchs Collected from Seven River Systems in Northern Australia and Papua New Guinea. Tokyo, Univ Mus Univ Tokyo, Nature and Culture, No. 3, pp 43–53.
16.
Johnson CS, Scronce BL, McManus MW (1984): Detection of DC electric dipoles in background fields by the nurse shark. J Comp Physiol A Sens Neural Behav Physiol 155:681–687.
17.
Kajiura SM (2000): Head morphology and electrosensory pore distribution of carcharhinid and sphyrnid sharks. Environ Biol Fishes 61:125–133.
18.
Kajiura SM (2003): Electroreception in neonatal bonnethead sharks, Sphyrna tiburo. Mar Biol 143:603–611.
19.
Kajiura SM, Cornett AD, Yopak KE (2010): Sensory adaptations to the environment: electroreceptors as a case study; in Carrier JC, Musick JA, Heithaus MR (eds): Sharks and Their Relatives. 2. Biodiversity, Adaptive Physiology and Conservation. Boca Raton, CRC Press, pp 393–434.
20.
Kajiura SM, Holland KN (2002): Electroreception in juvenile scalloped hammerhead and sandbar sharks. J Exp Biol 205:3609–3621.
21.
Kalmijn AJ (1974): The detection of electric fields from inanimate and animate sources other than electric organs; in Fessard A (ed): Electroreceptors and Other Specialized Receptors in Lower Vertebrates. Berlin, Springer, vol III/3, pp 147–200.
22.
Last PR, Stevens JD (1994): Family Pristidae, sawfishes; in Last PR, Stevens JD (eds): Sharks and Rays of Australia. Melbourne, CSIRO Publishing, pp 360–367.
23.
Last PR, Stevens JD (2009) Sharks and Rays of Australia, ed 2. Collingwood, CSIRO Australia.
24.
Liem KF, Summers AP (1999): Muscular system: gross anatomy and functional morphology of muscles; in Hamlett WC (ed): Sharks, Skates and Rays. The Biology of Elasmobranch Fishes. Baltimore, John Hopkins Press, pp 93–114.
25.
McFarland W (1991): Light in the sea: the optical world of elasmobranchs. J Exp Zool suppl 5:3–12.
26.
Murray RW (1974): The ampullae of Lorenzini; in Fessard A (ed): Electroreceptors and Other Specialized Receptors in Lower Vertebrates. Berlin, Springer, vol III/3, pp 125–146.
27.
Nelson M (2005): Target detection, image analysis, and modeling; in Bullock T, Hopkins C, Popper A, Fay R (eds): Electroreception. New York, Springer, pp 290–317.
28.
Otake T (1991): Serum composition and nephron structure of freshwater elasmobranchs collected from Australia and Papua New Guinea; in Shimizu M, Taniuchi T (eds): Studies on Elasmobranchs Collected from Seven River Systems in Northern Papua New Guinea. Tokyo, Univ Mus Univ Tokyo, Nature and Culture No. 3, pp 55–62.
29.
Peverell SC (2006): Distribution of sawfishes (Pristidae) in the Queensland Gulf of Carpenteria, Australia, with notes on sawfish ecology. Environ Biol Fishes 73:391–402.
30.
Raschi WG (1978): Notes on the gross functional morphology of the ampullary system in two similar species of skates, Raja erinacea and R. ocellata. Copeia 1:48–53.
31.
Raschi WG (1984): Anatomical Observations on the Ampullae of Lorenzini from Selected Skates and Galeoid Sharks of the Western North Atlantic; thesis, College of William and Mary, Williamsburg.
32.
Raschi WG (1986): A morphological analysis of the ampullae of Lorenzini in selected skates (Pisces, Rajoidei). J Morphol 189:225–247.
33.
Raschi WG, Keithran ED, Rhee WC (1997): Anatomy of the ampullary electroreceptor in the freshwater stingray, Himantura signifer. Copeia 1997:101–107.Sokal RE, Rohlf FJ (1995): Biometry: The Principles and Practice of Statistics in Biological Research, ed 3. New York, Freeman.
34.
Szamier RB, Bennett MVL (1980): Ampullary electroreceptors in the freshwater ray, Potamotrygon. J Comp Physiol 138:225–230.
35.
Thorburn DC, Morgan DL (2005): Threatened fishes of the world: Pristis microdon Latham 1794 (Pristidae). Environ Biol Fishes 72:465–466.
36.
Thorburn D, Morgan D, Gill H, Johnson M, Wallace Smith H, Vigilante T, Gorring A, Croft I, Fenton J (2004): Biology and cultural significance of the freshwater sawfish (Pristis microdon) in the Fitzroy River Kimberley, Western Australia. Freshwater Fish Group, Centre for Fish and Fisheries Research, Murdoch University. Threatened Species Network.
37.
Thorburn DC, Morgan DL, Rowland AJ, Gill HS (2007): Freshwater sawfish Pristis microdon Latham, 1794 (Chondrichthyes: Pristidae) in the Kimberley region of Western Australia. Zootaxa 1471:27–41.
38.
Thorburn DC, Morgan DL, Rowland AJ, Gill HS, Paling E (2008): Life history notes of the critically endangered dwarf sawfish, Pristis clavata Garman 1906 from the Kimberley region of Western Australia. Environ Biol Fishes 83:139–145.
39.
Thorburn DC, Peverell SC, Stevens JD, Last PR, Rowland AJ (2003): Status of freshwater and estuarine elasmobranchs in northern Australia. Canberra, Australian Department of Environment and Heritage.
40.
Tricas TC (2001): The neuroecology of the elasmobranch sensory world: why peripheral morphology shapes behaviour. Environ Biol Fishes 60:77–92.
41.
Whitehead DL (2002): Ampullary organs and electroreception in freshwater C. leucas. J Physiol Paris 96:391–395.
42.
Wilkens L, Hofmann M (2005): Behavior of animals with passive, low-frequency electrosensory systems; in Bullock T, Hopkins C, Popper A, Fay R (eds): Electroreception. New York, Springer, pp 229–263.
43.
Wueringer BE, Peverell SC, Seymour J, Squire L Jr, Collin SP (2011): Sensory systems in sawfishes. 2. The lateral line. Brain Behav Evol, DOI 329518.
44.
Wueringer BE, Squire L Jr, Collin SP (2009): The biology of extinct and extant sawfish (Batoidea: Sclerorhynchidae and Pristidae). Rev Fish Biol Fish 19:445–464.
45.
Wueringer BE, Tibbetts IR (2008): Comparison of the lateral line and ampullary system of two species of shovelnose ray. Rev Fish Biol Fish 18:47–64.
© 2011 S. Karger AG, Basel
2011
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.