Elasmobranchs are thought to possess an acute sense of smell, but the relationship between the anatomy of their olfactory organs and their sensory ecology is poorly understood. Moreover, the ecological diversity of elasmobranchs as a group indicates that there might be considerable interspecific variation in the importance of the olfactory sense. Wobbegong sharks, with their sedentary lifestyle and ambush predatory technique, probably utilize their senses differently than other shark species, making it difficult to generalize about their olfactory capabilities and olfaction-dependent behaviors. In this study, the number of olfactory lamellae and the surface area of the olfactory epithelium were measured as a means of assessing relative olfactory sensitivity in four species of wobbegong shark (the Western wobbegong, Orectolobus hutchinsi; the spotted wobbegong, O. maculatus; the ornate wobbegong, O. ornatus; and the dwarf spotted wobbegong, O. parvimaculatus). We also present a phylogenetic comparative analysis between wobbegongs and other elasmobranchs for which published data on olfactory morphology are available. There is a significant difference in the total number of olfactory lamellae between most species, but not between O. hutchinsi and O. maculatus, although the olfactory sensory surface area is comparable between these two species and O. ornatus. Orectolobus parvimaculatus has a significantly larger olfactory sensory surface area than the other three species, and there is a positive relationship between total body length and olfactory sensory surface area for all four species. Assuming that these morphological measures are true indications of olfactory capability, the olfactory abilities of wobbegongs are as good as, or better than, other benthic elasmobranchs. Interspecific differences in olfactory ability within this group of benthic ambush predators could indicate relative differences in prey detection, intraspecific recognition and mate detection.

Keywords:
Olfaction, Wobbegong, Shark, Sensory ecology, Behaviour, Diet, Olfactory epithelium
1.
Bell MA (1993) Convergent evolution of nasal structure in sedentary elasmobranchs. Copeia 1993:144–158.
2.
Bronshtein AA (1976) Some peculiarities of fine structure of the olfactory organ in elasmobranchs. Zh Evol Biokhim Fisiol 12:63–67.
3.
Burnham KP, Anderson DR (2002) Model Selection and Multimodel Inference. A Practical Information – Theoretic Approach. New York: Springer.
4.
Carraro R, Gladstone W (2006) Habitat preference and site fidelity of the ornate wobbegong shark (Orectolobus ornatus) on rocky reefs of New South Wales. Pac Sci 60:207–223.
5.
Carrier JC, Pratt Jr HL, Martin LK (1994) Group reproductive behaviors in free-living nurse sharks, Ginglymostoma cirratum. Copeia 1994:646–656.
6.
Chidlow JA (2003) The Biology of Wobbegong Sharks (Family: Orectolobidae) from South-Western Australian Waters. Townsville: James Cook University.
7.
Compagno LJV (1984) FAO species catalogue. Vol. 4, Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Part 1. Hexanchiformes to Lamniformes. FAO Fisheries Synopsis.
8.
Compagno LJV (2001) Sharks of the World. An annotated and illustrated catalogue of Shark species known to date. Volume 2. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). FAO Species Catalogue for Fishery Purposes. No. 1, Vol. 2. Rome: FAO.
9.
Compagno L, Dando M, Fowler S (2005) A Field Guide to the Sharks of the World. London: Harper Collins Publishers Ltd.
10.
Ferrando S, Bottaro M, Gallus L, Girosi L, Vacchi M, Tagliafierro G (2006) Observations of crypt neuron-like cells in the olfactory epithelium of a cartilaginous fish. Neurosci Lett 403:280–282.
11.
Fishelson l, Baranes A (1997) Ontogenesis and cytomorphology of the nasal olfactory organs in the Oman shark, Iago omanensis (Triakidae), in the Gulf of Aqaba, Red Sea. Anat Rec 249:409–421.
12.
Gordon I (1993) Pre-copulatory behaviour of captive sandtiger sharks, Carcharias taurus. Environ Biol Fish 38:159–164.
13.
Grafen A (1989) The phylogenetic regression. Phil Trans R Soc Lond B 326:119–157.
14.
Holl A (1973) Feinstruktur des Riechepithels von Chimaera monstrosa (Holocephali). Marine Biol (Berlin) 23:59–72.
15.
Huveneers C (2006) Redescription of two species of wobbegongs (Chondrichthyes: Orectolobidae) with elevation of Orectolobus halei Whitley 1940 to species level. Zootaxa 1284:29–51.
16.
Huveneers C, Otway NM, Gibbs SE, Harcourt RG (2007a) Quantitative diet assessment of wobbegong sharks (genus Orectolobus) in New South Wales, Australia. ICES J Mar Sci 64:1–10.
17.
Huveneers C, Otway NM, Harcourt RG (2007b) Morphometric relationships and catch composition of wobbegong sharks (Chondrichthyes: Orectolobus) commercially fished in New South Wales, Australia. Proc Linn Soc NSW 128:243–249.
18.
Johnson RH, Nelson DR (1978) Copulation and possible olfaction-mediated pair formation in two species of carcharhinid sharks. Copeia 1978:539–542.
19.
Kajiura SM, Forni JB, Summers AP (2005) Olfactory morphology of Carcharhinid and Sphyrnid sharks: does the cephalofoil confer a sensory advantage? J Morphol 264:253–263.
20.
Klimley AP (1980) Observations of courtship and copulation in the nurse shark, Ginglymostoma cirratum. Copeia 1980:878–882.
21.
Last PR, Chidlow JA (2008) Two new wobbegong sharks, Orectolobus floridus sp. nov. and O. parvimaculatus sp. nov. (Orectolobiformes: Orectolobidae), from southwestern Australia. Zootaxa 1673:49–67.
22.
Last PR, Stevens JD (1994) Sharks and Rays of Australia. Australia: CSIRO.
23.
Last PR, Chidlow JA, Compagno LJV (2006) A new wobbegong shark, Orectolobus hutchinsi n. sp. (Orectolobiformes: Orectolobidae) from southwestern Australia. Zootaxa 1239:35–48.
24.
Lisney TJ (2004) Neuroethology and Vision in Elasmobranchs. Brisbane: The University of Queensland.
25.
Lisney TJ, Collin SP (2006) Brain morphology in large pelagic fishes: a comparison between sharks and teleosts. J Fish Biol 68:532–554.
26.
Lisney TJ, Bennett MB, Collin SP (2007) Volumetric analysis of sensory brain areas indicates ontogenetic shifts in the relative importance of sensory systems in elasmobranchs. Raffles Bull Zool Suppl 14:7–15.
27.
Luer CA, Gilbert PW (1985) Mating behavior, egg deposition, incubation period, and hatching in the clearnose skate, Raja eglanteria. Environ Biol Fish 13:161–171.
28.
Meng Q, Yin M (1981) A study of the olfactory organ of the sharks. Trans Chin Ichthy Soc 2:1–24.
29.
Myrberg Jr AA, Gruber SH (1974) The behavior of the bonnethead shark, Sphyrna tiburo. Copeia 1974:358–374.
30.
Northcutt RG (1977) Elasmobranch central nervous system organization and its possible evolutionary significance. Am Zool 17:411–429.
31.
Northcutt RG (1978) Brain organization in the cartilaginous fishes. In: Sensory Biology of Sharks, Skates, and Rays (Hodgson ES, Mathewson RF, eds), pp 117–193. Arlington, VA: Office of Naval Research.
32.
Paradis E, Claude J, Strimmer K (2004) APE: analyses of phylogenetics and evolution in R language. Bioinformatics 20:289–290.
33.
Parker GH (1914) The directive influence of the sense of smell in the dogfish. Bull US Bureau Fish 33:61–68.
34.
Parker GH, Sheldon RE (1913) The sense of smell in fishes. Bull US Bureau Fish 32:33–46.
35.
Pinheiro J, Bates D, DebRoy S, Sarkar D, team tRC (2007) nlme: Linear and Nonlinear Mixed Effects Models. R package version 3.1–85.
36.
Reese TS, Brightman MW (1970) Olfactory surface and central olfactory connexions in some vertebrates. In: Taste and Smell in Vertebrates (Wolstenholme GEW, Knight J, eds), pp 115–149. London: J & A Churchill.
37.
Schluessel V, Bennett MB, Bleckmann H, Blomberg S, Collin SP (2008) Morphometric and ultrastructural comparison of the olfactory system in elasmobranchs: the significance of structure-function relationships based on phylogeny and ecology. J Morphol 269:1365–1386.
38.
Sheldon RE (1911) The sense of smell in selachians. J Exp Zool 10:51–62.
39.
Sorensen PW, Caprio J (1998) Chemoreception. In: The Physiology of Fishes (Evans DH, ed), pp 375–405. Boca Raton, FL: CRC Press.
40.
Takami S, Luer CA, Graziadei PPC (1994) Microscopic structure of the olfactory organ of the clearnose skate, Raja eglanteria. Anat Embryol 190:211–230.
41.
Tester AL (1963) Olfaction, gustation, and the common chemical sense in sharks. In: Sharks and Survival (Gilbert PW, ed), pp 255–282. Boston: DC Heath and Company.
42.
Theisen B, Zeiske E, Breucker H (1986) Functional morphology of the olfactory organs in the spiny dogfish (Squalus acanthias L.) and the small-spotted catshark (Scyliorhinus canicula (L.)). Acta Zool Stockh 67:73–86.
43.
Tricas TC (1980) Courtship and mating-related behaviors in myliobatid rays. Copeia 1980:553–556.
44.
Venables WN, Ripley BD (2002) Modern Applied Statistics with S, fourth edition. New York: Springer.
45.
Yamamoto M (1982) Comparative morphology of the peripheral olfactory organs in teleosts. In: Chemoreception in Fishes. Developments in aquaculture and fisheries science (Hara TJ, ed), vol 8, pp 39–59. New York: Elsevier.
46.
Yopak KE, Lisney TJ, Collin SP, Montgomery JC (2007) Variation in brain organization and cerebellar foliation in Chondrichthyans: sharks and holocephalans. Brain Behav Evol 69:280–300.
47.
Zeiske E, Caprio J, Gruber SH (1986) Morphological and electrophysiological studies on the olfactory organ of the lemon shark, Negaprion brevirostris (Poey). In: Indo-Pacific Fish Biology: Proceedings of the Second International Conference on Indo-Pacific Fishes (Uyeno T, Arai R, Taniuchi T, Matsuura K, eds), pp 381–391. Tokyo: Ichthyological Society of Japan.
48.
Zeiske E, Theisen B, Breucker H (1987a) Olfactory organs in pelagic and benthic elasmobranchs. Chem Sens 12:203.
49.
Zeiske E, Theisen B, Gruber SH (1987b) Functional morphology of the olfactory organ of two carcharhinid shark species. Can J Zool 65:2406–2412.
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