Animal Species:Bull Shark, Carcharhinus leucas Valenciennes, 1839
The Bull Shark is one of the few sharks that are potentially dangerous to people and is probably responsible for most of the shark attacks in and around Sydney Harbour.
The species is also the only widely distibuted shark that stays in fresh water for long periods of time to feed and breed. Females sometimes give birth in river mouths were the young will live for up to 5 years.
Alternative Name/s
The Bull Shark has also been called the River Shark, Freshwater Whaler, Estuary Whaler and Swan River Whaler.
Identification
The Bull Shark can be recognised by a combination of characters including a stout body, short blunt snout, triangular serrated teeth in the upper jaw and no fin markings as an adult. The species has a second dorsal fin about one third the height of the first, a small eye, and no skin ridge between the two dorsal fins. It is grey above and pale below, sometimes with a pale stripe on the flank.
Size range
The species grows to a length of 3.4 m.
Distribution
This species has a widespread distribution in tropical and warm temperate waters worldwide. In Australia the Bull Shark occurs from south-western, Western Australia, around the northern coastline and down the east coast to the central coast of New South Wales.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.
Distribution by collection data
Ozcam map of Bull Shark specimens in the Australian Museuma.
Habitat
The Bull Shark can live in a wide range of habitats from coastal marine and estuarine, to freshwater. It has been recorded from the surf zone down to a depth of at least 150 m. It is the only species of shark that is known to stay for extended periods in freshwater. It has been reported nearly 4000 km from the sea in the Amazon River system, and is known to breed in Lake Nicaragua, Central America.
Feeding and Diet
It has an omnivorous diet which includes fishes (including other sharks), dolphins, turtles, birds, molluscs, echinoderms and even terrestrial mammals including 'antelope, cattle, people, tree sloths, dogs and rats’ (Compagno, 1984; 480). They possibly even bite horses ... (see link attachment in comment from Local, below).
Economic/social impacts
It is an aggressive species that is considered dangerous to humans. Some authors consider that the Bull Shark may be more dangerous than the White Shark and the Tiger Shark. This is because of the Bull Shark's omnivorous diet and habitat preferences. The species may be found in murky water, where the splashing of a swimmer could be mistaken for a struggling fish.
The 2.8 m long fish in the images was caught on 18 February 1999, in a commercial fishing net near Grotto Point, Middle Harbour (Sydney Harbour) by T. and V. Depasquale and S. Virtu. This catch was a most unusual occurrence which attracted significant media interest. The specimen was on display at the Sydney Fish Markets for a week (where the images were taken) before it was donated to the Australian Museum by G. Costi (De Costi Seafoods). The specimen is now registered in the Australian Museum Fish Collection (AMS I.39432-001).
Classification
- Species:
- leucas
- Genus:
- Carcharhinus
- Family:
- Carcharhinidae
- Class:
- Chondrichthyes
- Subphylum:
- Vertebrata
- Phylum:
- Chordata
- Kingdom:
- Animalia
References
- Compagno, L. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 2. Carcharhiniformes. FAO Fish.Synop., (125) Vol.4, Pt.2: 251-655.Last, P.R. & J.D. Stevens. 1994. Sharks and Rays of Australia. CSIRO. Pp. 513, Pl. 1-84.
- Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
- Paxton, J.R. 2003. Shark nets in the spotlight. Nature Australia. Spring. 27 (10): 84.
Mark McGrouther
, Collection Manager, Ichthyology
Last Updated:
Tags fish, ichthyology, Bull Shark, Carcharhinus leucas, dangerous, Carcharhinidae, fresh water, marine, adult, shark attack, River Shark, Freshwater Whaler, Estuary Whaler, Swan River Whaler, stout body, short blunt snout, triangular serrated teeth, no fin markings, small eye, grey, pale underside, pale stripe, > 2m,
18 comments
Hi again Local. Apologies. I did not see that your message had an attachment. Thank you for adding that! Were there any tooth fragments in the wound. As I mentioned before, I am curious if anything was published about the incident. I'd like to be able to cite a reference on this page.
Hi Local. That's an interesting account. Thank you for your comment. I had not heard of this before. Are you a veterinarian and do you have any documentation of the incident. I don't necessarily want to add gorey photos to the website!
Pleased to be of assistance Bandicoot. FYI there is an article in the Queensland Museum book "Wildlife of Greater Brisbane" (2007 edition) entitled 'Sharks in the Brisbane River' (pages 177-179) which you may find informative.
Hi Syra, Thank you for your comment. I was very interested to read your statement that the Bull Shark "pumps more testosterone than a bull elephant". That's an interesting statistic that I have not heard of before. Can you please tell me where you read/heard this?
Hi bandycoot. I guess the first thing to say is that as you know, the chance of being attacked by any sort of shark is very remote indeed. Having said that, many people regard the Bull Shark as the most dangerous species to humans because the species has an aggressive nature, powerful jaws, non-specific diet and can live in a wide range of habitats that include often turbid, estuarine and freshwater habitats. Last and Stevens, 2009 (see references) state that the Bull Shark "penetrates far into fresh water for extended periods, where it occasionally even breeds. It can tolerate hypersaline conditions (up to 53 parts per thousand in the St Lucia lake system in South Africa) and is often found in turbid waters. It has been reported from numerous freshwater systems in warm temperate Australia, including the Fitzroy, Ord, Adelaide, Daly, East Alligator, Mitchell, Normanby, Herbert, Brisbane, Clarence and Swan Rivers and Lake Macquarie. Unfortunately I don't know the area that you refer to well enough to be able to comment with any authority. I will email my colleague who works at the Queensland Museum and ask for his opinion.
Hi Kels, Your question is a tough one to answer. I would suggest that a species is 'native' to anywhere it has not been introduced or 'recently' colonised. To my knowledge the Bull Shark's widespread distribution is a natural phenomenon and thus it is 'native' throughout its distribution. This may seem a little strange when you compare it to the native distribution of a terrestrial plant or animal that is endemic to (only found in) one particular region. I hope this helps.
A long term Mt Crosby resident and fisherman reports that there were well known barbed wire hazards in the river near Kholo Crossing that may have caused the injury to the horse. He says members of the local freshwater fishing association have never noted Bull Sharks above the weir, despite many being active on this part of the river for over 50 years.