Morphology and distribution of the ampullary electroreceptors in wobbegong sharks: implications for feeding behaviour

The electrosensory capabilities of wobbegong sharks are of particular interest, partly because very little is known about their behavioural ecology and specifically because of their unusual ambush predatory strategy and benthic lifestyle. While several biological functions of electroreception have been proposed, less consideration has been given to the functional significance of interspecific differences in the morphology and topographic distribution of the ampullary organs. The morphology of the ampullary organs was examined in four species of wobbegong shark, and the distribution of electroreceptive pores was mapped in two species. The ampullary systems of wobbegongs are similar in morphology to other marine elasmobranchs. The number of alveoli per ampullae is not significantly different between the four species; however, differences are seen between ampullary cell size in some species. Ampullary pore distribution patterns are relatively unique, with the majority of pores occurring on the dorsal region of the head. Wobbegongs feed primarily on demersal teleost fishes, and as the benthic and well-camouflaged wobbegong remains motionless, these fish could be easily detected by the dorsal pores when swimming within range.