THE WOBBEGONG FAMILY GROWS AGAIN

In the last decade, the wobbegong shark family has expanded with five new species described from Australia and one from Indonesia , doubling the known species from six to twelve. But other undescribed species of these colourful sharks are thought to exist and divers can help to sort out the wobbegong family tree with images and information.
    Wobbegongs are bottom dwelling sharks with shaggy beards, camouflaged skin patterns and a very cryptic nature. They are the ultimate ambush predators – armed with a mouthful of sharp dagger-like teeth. Until several years ago only six species of wobbegongs were known to science, five Australian species -spotted wobbegong (Orectolobus maculatus), ornate wobbegong (O. ornatus), northern wobbegong (O. wardi), tasselled wobbegong (Eucrossorhinus dasypogon) and cobbler wobbegong (Sutorectus tentaculatus) - and one species from overseas - Japanese wobbegong (O. japonicus). But in 2006 the family got a shake up with two new species added to that list.
    The first was the banded wobbegong (O. halei), which was long thought to be the adult form of the ornate wobbegong, but a study by Charlie Huveneers (while doing a PhD at Macquarie University) identified them as two separate species. Meanwhile the western wobbegong (O. hutchinsi), found only in southern Western Australia and long known as a valid species, was finally described by Peter Last (CSIRO), Leonard Compagno (Iziko Museum of Cape Town) and Justin Chidlow (Western Australian Department of Fisheries).
    Justin’s research on Western Australian wobbegongs also saw the discovery of two other species in the southern waters of the state, the floral banded wobbegong (O. floridus) and dwarf spotted wobbegong (O. parvimaculatus), both of which were described in 2008. The distribution of the former is documented as Augusta north to Geraldton and the latter is known from Mandurah north to Shark Bay . As the name suggests the floral banded wobbegong has a distinctive flower-like skin pattern and has so far only been captured in deep water, 42-85m, while the dwarf spotted wobbegong has a skin pattern similar to the larger spotted wobbegong (with which it could easily be confused), but is less than a metre long and is known from shallow to deep waters (9-135m). Divers have no doubt come in contact with these new wobbegong species, but as yet no underwater images of these sharks have surfaced.
    The northern wobbegong is Australia’s smallest and least known species, found in tropical waters off Western Australia and a few island localities off the Northern Territory (Melville I), Cape York (Thursday Island) and possibly Papua New Guinea and Indonesia. Ongoing research by Peter Last, John Pogonoski ,  Charlie Huveneers and Shannon Corrigan has found that there are at least three colour variations being called the northern wobbegong, one of which was recently described as a separate species. The network wobbegong (O. reticulatus) is known from Darwin to Broome, but only a handful of these sharks have so far been found. Additional colour forms of the northern wobbegong have been identified from other localities including Shark Bay and the Monte Bello Islands (WA), Ashmore Reef off northern WA and the Torres Strait / Cape York region (Qld).
    2010 has also been a busy year for the wobbegong family with another member added from Indonesian waters. Peter Last, John Pogonoski and William White (CSIRO, Hobart) described the Indonesian wobbegong (O. leptolineatus) which is found off Bali and Lombok, and possibly through to West Papua . This uncommon shark has only occasionally been seen by divers. There is a possibility that other undescribed wobbegongs may also be found in Indonesia or surrounding Southeast Asian waters.
    The abovementioned researchers are still working on these potential new species and are interested in any images that divers have taken of wobbegongs from tropical Australia or South-East Asia . If you have images of wobbegongs that you cannot identify or images you think may be of interest to researchers, please send them to me at nigel@nigelmarshphotography.com and I will pass them on to the researchers or email them directly to john.pogonoski@csiro.au
    With any luck Australia ’s unique shark fauna will continue to thrive and we can better understand the iconic Aussie shark family – the ‘wobbies’.

Article appeared in Dive Log No.266 September 2010