shark Archives - Sharks And Rays Australia

Unexpected mail

by Barbara | Dec 10, 2019 | Blog | 0 comments

by Nikki Biskis

In September 2018, SARA received what is probably the cutest scientific interview of all time. Billy, Charlie, Dylan and Jayden of Birmingham Primary School in Mount Evelyn, VIC, had some very creative questions regarding sharks and rays. So, naturally, four lucky biologists from the SARA team responded right back to these curious minds. Some of our favourites are below!

Do some sharks fight?

Sharks do not really fight very often but bigger sharks do scare off smaller sharks. If two sharks are swimming straight towards each other the smaller shark is the one that will move out of the way to let the big one carry on swimming. Big sharks can also eat small sharks!

Do sharks mean to eat people?

No! Unlike humans, sharks don’t have any hands, so they can’t pick things up to figure out what they are. Instead they take a bite. Only once they take a taste of something can they be sure of what it is. Humans are not on the normal menu for sharks. So usually once they taste us they don’t want another bite.

Do sharks smell oil?

Sharks have an incredible sense of smell, so it is very likely they can smell oil. Nearly two thirds of a shark’s brain is for thinking about smells and they can sniff out just one teaspoon of fish blood from a swimming pool sized area of water.

Sawfish or sawshark?

by Barbara | Feb 18, 2019 | Blog | 0 comments

By Paddy Burke (Sharks4Kids ambassador & PhD student at Macquarie University, @Patrick_Burke)

The ocean is filled with so many incredible creatures, incredible and bizarre. Many of these fish have evolved under similar pressures which have led them to look quite similar even if they are genetically quite distinct. This similarity in appearance or development of similar structures is what is known as homology. One great example for this can be seen in sawfish and sawsharks!

Now many of you may be saying, wait, aren’t those the same thing? The answer is no! While these two groups of fish are very similar in appearance, they actually have quite a few big differences that can make it easy to tell them apart once you know them! The differences we will cover today are their ‘saws’, general body size and the gills.

The ‘saws’ or elongated toothed rostra are the features that make these fish really quite unique. The saw is thought to be used for predation and defense in both groups. However, the actual structure of the saw is really quite different! Sawfish saws are lined with a number of teeth along both sides of their saw that vary in size and number by species but each one of these teeth are permanent! Meaning that if they happen to lose one it will never grow back. The rostral teeth of sawfish also grow from their base, like a rodent’s tooth, so that the animals can sharpen them regularly in the sand. Sawsharks on the other hand have a very different saw. Teeth can be found along both sides of the saw like in sawfish, however, sawshark teeth are replaceable! The most distinguishable feature to separate a sawfish and a sawshark saw is the presence of what are called ‘barbels’. Barbels are found only on sawshark saws and they look like a little moustache coming off the saw. This moustache is thought to have a tactile function, meaning they use them to feel around in the sand for food.

The size of fish is an easy indicator of species between these groups. Sawfish are very large fish, some reaching over 7 meters in length! While sawsharks are much smaller, averaging around 1 meter for an adult depending on species. In addition to size, it is important to know that sawfish are technically rays while sawsharks are true sharks. What that means is that in sawfish you will find their gills located on the underside of the fish. Where as in sharks they are located on the side of the head.

These fish could be considered ‘cousins’ in a way since they are both chondrichthyans, meaning they both have a skeleton made out of cartilage instead of bone. However, it is important to remember that sawfish are actually rays while sawsharks are true sharks. Sawfish may not follow the typical body plan of their relatives the stingrays, but they are more closely related to them than they are to sawsharks!

A sawshark, Pristiophorus nudipinnis resting on the substrate. See the barbels? Image by Tristan Guttridge.

A freshwater sawfish, Pristis pristis, is disentangled from a gill net in order to be tagged and released. Its teeth are evenly sized and spaced, contrary to those of sawsharks. Image by Dave Nash.

When art meets conservation

by Barbara | Jun 8, 2018 | Blog | 0 comments

When I heard that Pangea Seed Foundation was considering to use Cairns as the canvas for their first Australian Sea Walls event, I was really excited. The foundation had been doing amazing work over many years, and after meeting Akira Biondo at a conference on sharks and rays in Berlin, Germany in 2012, I was one of their keen followers. Pangea Seed is the brainchild of Tre Packard and his wife Akira, and funds raised through are used to inspire marine conservation in children. One of the big topics the foundation took on was to teach children about shark finning.

Their work in schools is inspiring, but also is the artwork. The event in Cairns brought together 20 mural artists, both internationally acclaimed as well as locally famous. Various events were organised to inspire their murals, and this is where Sharks And Rays Australia got involved. After all, a mural of a sawfish can reach hundreds of thousands of people from around the world, if placed in the right location in Cairns!

At the beginning of May, I returned early form a field trip in the Northern Gulf of Carpentaria, to join a panel discussion with the artists and founders of Pangea Seed at the Cairns Tanks Arts Centre. Some of the points raised during this discussion were how art can change people’s perceptions of animals. For example, sharks are generally perceived to be dangerous, but a mural of a shark can be perceived to be beautiful, and it is this moment in which the observer’s mind opens, and becomes receptive and curious to the possibility that the long hold perception of the mindless killer might be wrong.

Below you will find the map of murals that were produced across Cairns, I hope you enjoy them for years to come.

Blacktip reef shark mural

by @BronteNaylor

Image of Henrietta Fourmile Marrie from the Yarahbah community. Henrietta was leading a major campaign at the UN to give the rights over Indigenour knowledge back to Indigenous people.

by @claire_foxton

A Queensland grouper

by @amokisland

A humphead maori wrasse

by @VANStheOmega

The fringe animals mural

by @caroline_mudge includes a sawfish!

A sawfish on the wall of Cairns Central

by @mrcinzah!!

A sawfish on the wall of Cairns Central

by @mrcinzah!!

“Convenience equals consequence”

by @fuzeillear

Sea Walls Cairns Map

SeaWalls 2018 Welcome

by Barbara | Apr 1, 2018 | Blog | 0 comments

SARA welcomes the Sea Walls artists to Cairns!

Here, at Sharks And Rays Australia we are super excited to have you wonderful people visit Cairns on your inspirational mission to create artwork for marine conservation! My name is Barbara and I am the Director and Principal Scientist of SARA. In the image to the right you can see me doing what I love, which is working with and raising awareness for SAWFISH.

Sawfish used to be quite common here in Far North Queensland, but nowadays they are rare. Globally their chances are even worse and the freshwater sawfish, Pristis pristis, is considered to be amongst the 100 most endangered species in the world. Given that their reduction in numbers has a lot to do with people taking the saws as trophies (I think this makes sawfish our own aquatic rhinos, sadly), raising awareness for sawfish is one of the most important things we can do to ensure these magnificent animals will exist into the future.

I’ve created this page for you to get you excited about sawfish! I hope you enjoy the materials below. I will meet you all at the forum at the Tanks Arts Centre on may 3, for which I return early from a field trip. if you have any questions about sawfish, please get in touch barbara(at) saw.fish

Thank you for choosing Cairns as the canvas for your art!

cheers,

Barbara

Check out this image above from the State Library of Queensland of a sawfish that was caught at the mouth of the Mulgrave River, just south of Cairns, in 1938. Sawfish generally inhabit shallow waters, but these large animals are hardly encountered anymore. This breaks my heart, just imagine how amazing it would be to see such a creature!

Now let me take you on a journey to Northern Queensland, where we work with sawfish and other sharks and rays!

Below you can watch our video on the saw-less sawfish. People chopping off the saws of live sawfish for trophies seems to become an issue in Queensland. SARA’s data collected over the last 2.5 years indicates that 5-10% of all sawfish we have captured our captures that have been submitted to us are sawless. A study by our collaborators form WA, Team Sawfish indicates that these animals can take up to 3 months to starve to death.

Here is another video by Jeremy Wade’s show RiverMonsters from WA, where he captured a happy little sawfish pup in the Fitzroy River

Here is another educational video from our colleagues at NESP in the NT. Enjoy!

Last but not least you can read some more about Australian sawfish in an article written by my colleague and friend Nicole Phillips (she works on sawfish genetics) and myself. You can access the article here.

Have you heard that a sawfish was found 700km inland in the Northern Territory? Here is a link to the ABC article. It also shows some amazing rock art of sawfish. I recently spoke with an Indigenous Ranger who told me about sawfish rock art in the Laura region, 4 hrs north of Cairns, indicating the cultural importance of these animals to the Great Barrier reef region. Below is an image of a sawfish from Burketown, in the Southern Gulf region.