Thread by @mcmsharksxx

Good morning Twitter! I move to Australia today! 1 like/retweet of this tweet = 1 thing you (maybe) didn't know about Australian #sharks.

Alright, let's get this party started: First, numbers aren't 100% accurate but anywhere from 170-190 species of #sharks call Australian waters home. That's a lot, seeing as how there are roughly 500-ish species.

According to the Australian Government's Department of Environment and Energy, of those 170-190 species, around 70 are thought to be endemic. Endemic means "native to a specific region or environment and not occurring naturally anywhere else."

#Sharks in #Australia are found all over- even in freshwater! Also according to the Australian Government's website, the majority of these #sharks are found on the continental slope or shelf. What's that? Next tweet!

Continental shelf: Extends from a continent underwater, resulting in a shallow-water area. Continental slope: Steep slope from continental shelf to ocean floor; usually around 20 km (12.4 miles) wide and made up of mud and silt substrate. It is an ideal area for deep sea fishing.

#Australia passed the Environment Protection and Biodiversity Conservation Act 1999 where it is an "offence to kill, injure, take, trade, keep, or move any member of a listed threatened #shark species on Australian Government land or in Commonwealth waters without a permit."

#Australia is also a participating member of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - and there are a number of #shark (and #flatshark!!!) species that call Australian waters home that are protected under CITES.

The Memorandum of Understanding on the Conservation of Migratory #sharks was developed under the Convention on the Conservation of Migratory Species of Wild Animals (CMS). #Australia was one of the first (14th) countries to sign Sharks MoU - they did so back in 2011!

Now on to some cool #sharks that live in #Australia. First, the biggest of them all: the whale shark (Rhincodon typus)! Many people travel to Ningaloo Reef (on the western side of Australia) to go snorkeling with these animals- I hope to do so through #ecotourism!

My favourite #flatshark lives in #Australia: the magpie fiddler ray! It is considered to be a colour variant of T. dumerilii (Donnellan et al. 2015). You can read more about them here: finsunited.co.nz/bite-blog/magp…

In fact, I won't just make this thread about just #sharks because #Australia has (arguably) the world's highest diversity of sharks and rays!

So while there are some unfamiliar #diverseshark faces in Australia, there are very familiar ones too. For example, arguably the most (in)famous of all shark species... the great white shark, Carcharodon carcharias: finsunited.co.nz/bite-blog/grea…

Great white shark (GWS) Mitochondrial DNA (mtDNA) shows that the populations of South Africa and #Australia (and NZ) are genetically different populations! The relationship between these populations is still largely unknown.

In fact, a GWS performed a previously unknown fast transoceanic return migration spanning the entire Indian Ocean, swimming coast-to-coast from South Africa to #Australia and back. Read all about it here: whitesharktrust.org/pages/article/…

One more cool #finfact about GWS and I'll move on: while in the uterus, the embryonic white sharks swallow their own sets of shed teeth; this may be to re-utilize calcium and other minerals.

Next #flatshark I want to talk about that calls #Australia home is the blue skate, Notoraja azurea, which is a small, brilliantly coloured sapphire skate. They are seen from Western Australia to New South Wales including waters around Tasmania! WOW! finsunited.co.nz/bite-blog/blue…

There are three modes of reproduction in #sharks and all three are found in #Australia:

Laying eggs (oviparous)
Live bearing (viviparous)
Young hatching from eggs within the mother (ovoviviparous)

The southern eagle ray (Myliobatis tenuicaudatus; you can see them in this video) are commonly found near beaches, shoals and over sandflats in shallow water off temperate southern #Australia (Western AU to Queensland) including Tasmania and New Zealand.

The short tail stingray, Dasyatis brevicaudata (aka smooth stingray), is a species in the Dasyatidae family. Is seen off southern Africa and southern #Australia and New Zealand, and range from the intertidal zone to a depths of 480 m (1,570 ft). finsunited.co.nz/bite-blog/shor…

The crested bullhead #shark (Heterodontus galeatus) and are seen off the eastern coast of #Australia. However, they’re an uncommon resident. P.S. They're in the bullhead shark family (Heterodontidae)! finsunited.co.nz/bite-blog/cres…

The false peacock skate (Pavoraja pseudonitida), a member of the Arhynchobatidae family, is a #flatshark found mostly on the upper continental shelf off of Queensland, #Australia. In fact, it may be the most abundant skate on the upper continental slope off tropical eastern AU.

The spotted wobbegong (Orectolobus maculatus) belongs to the Orectolobidae family, and is found in the eastern Indian Ocean around #Australia; it is possibly endemic to this region. A relatively large #shark, reaching lengths of up to 3m/9.8 ft!

Other common names for wobbegong #sharks are are "carpet shark," "common carpet shark," "common catshark," and "tassel shark." The word 'wobbegong' itself is an Australian aboriginal word!

The western numbfish (Narcine lasti) are seen in the outer continental shelf and upper slope off northwest #Australia (Northern Territory to Western Australia), and they forage for prawn and scampi in the muddy substrates. #flatsharks

The Western round skate (Irolita westraliensis) is found on the outer continental shelf off northwestern #Australia and can get up to 43 cm in length. #Finfact: they are the second member of the endemic Australian genus Irolita.

The Southern round skate (Irolita waitii) is the other member of the endemic Australian genus Irolita opposite the Western round skate (Irolita westraliensis). #Finfact: The Southern round skate was almost described a century ago!

The golden eye shovelnose ray (Rhinobatos sainsburyi) may be one of my favourite common names of all time. Like, doesn’t the name “golden eye” just sound… so cool? (Or maybe I’m just riding a #ThorRagnarok movie high right now.) Lives in #Australia!

The golden eye shovelnose ray (Rhinobatos sainsburyi) are commonly seen on the continental shelf off northwestern #Australia from Western Australia to the Northern Territory. #flatsharks

The sicklefin houndshark (Hemitriakis falcate) are currently known only on the continental shelf of western #Australia (from Exmouth Gulf to Broome in western Australia at depths of 110 - 200 metres (m) deep.

And this can't be a #diversesharks party without bringing in the #ghostsharks. Hello Marbled ghost shark (Hydrolagus marmoratus): finsunited.co.nz/bite-blog/marb…

Marbled ghost shark (Hydrolagus marmoratus) can be observed on the continental slope off eastern Australia (Queensland to New South Wales region). #chimaerasneedlove2

The western shovelnose ray (Aptychotrema vincentiana) are found off southern and western #Australia up to depths of 125 m deep; here, they eat decapod crustaceans and teleost fish. #flatsharks

There are sixgill sharks… and there are sixgill #stingrays. Betcha didn’t know that! The sixgill stingray, Hexatrygon bickelli, re found in the waters off Southern Africa, Java, Japan, Taiwan, Hawaii, Philippines, New Caledonia and #Australia. Quite a large distribution!

The giant shovelnose ray (Glaucostegus typus) are widely distributed in the Indo-Pacific from India to eastern Australia. Here, they enjoy a healthy appetite of prawns, crabs, small fishes, and cephalopods. They are currently listed as Vulnerable (VU) by the IUCN.

The smallspine spookfish (Harriotta haeckeli) belongs to the family Rhinochimaeridae—the long-nosed chimaeras! They have been observed around #Australia in waters of 1480-1950 metres deep.

The pale skate (Notoraja ochroderma) is… well, pale in colour. (Surprise!) A few specimens have been taken from continental slope off Cairns (Queensland, Australia) but not much else is known about these animals.

The ghost skate (Notoraja hirticauda) is another pale coloured skate. They are found on the continental slopes off Shark Bay to the Monte Bello Islands in Western #Australia at depths of 500-760 metres (m).

The blackfin ghostshark (Hydrolagus lemures) have a widespread distribution along the Australian continental slope (think Western Australia to Queensland and Tasmania)... but little is known about them! Typical for #chimaeras.

The Coffin ray (Hypnos monopterygius) has my second favourite common name. The coffin ray is much like myself enjoys the tropical and warm temperate waters of #Australia; specifically, it can be seen from western Australia, to New South Wales all the way to Queensland.

Heterodontus portusjacksoni is named after Port Jackson, Australia, where it is commonly seen. They have a few monikers, including, “bullhead,” “oyster-crusher,” “tabbigaw” (if someone wants to explain that one to us), “pigfish,” “pig” and “horn shark.”

Port Jackson #sharks are found exclusively in #Australia, off the temperate southern coast. There have been a few sightings off the northern coast of AU, and off the coast of New Zealand, yet not much evidence exists to say there is a population.

Another famous #Australian shark will be introduced by David Attenborough: The epaulette shark (Hemiscyllium ocellatum).

The epaulette #shark (Hemiscyllium ocellatum) are found in the western Pacific Ocean around New Guinea and northern #Australia (think Shark Bay to Newcastle). They may even reside in Malaysia, Indonesia and the Solomon islands (but there are no confirmed reports yet).

The coral catshark (Atelomycterus marmoratus) commonly seen off Pakistan, India to Malaysia, Indonesia, the Philippines, Papau New Guinea, southern China and Japan. There have been some spotted off Australia, but these catsharks are thought to be another species altogether.

The boreal skate (Amblyraja hyperborea) is the opposite of what I am: anti-tropical. Found in the temperate parts of the Atlantic and Pacific Oceans, they are common residents of lower continental slopes off southern Australia and New Zealand, recorded from 980 to 2000 m deep.

The spotted shovelnose ray (Aptychotrema timorensis) get up to ~58 cm in length, with few specimens being caught from the Timor Sea. These individuals were caught off Melville Island, Northern Territory, Australia. Like some rays, their diets and reproductive methods are unknown.

The Melbourne skate (Spiniraja whitleyi) can reach up to 200 cm in length! Both juveniles and adults can be seen around the continental shelf between New South Wales and Western #Australia, including Tasmania, up to 345 m deep! #flatsharks

The ornate wobbegong (Orectolobus ornatus) found primarily in western Pacific Ocean. Seen around Australia, ranging from Port Douglas in North Queensland to Sydney; to better educate the public about these carpet sharks, a few of them star in SEA LIFE Sydney Aquarium's exhibits.

The largetooth cookiecutter shark (Isistius plutodus) is the second species in the Isistius genus. The sole specimen is registered in the Australian Museum Ichthyology Collection (AMS I.28924-001). Also recorded in Gulf of Mexico, off Japan and from eastern Atlantic to Australia.

The eastern shovelnose ray (Aptychotrema rostrata) found on the continental shelf off eastern Australia between Queensland and New South Wales (both Australian territories), they usually venture no more than 100 m deep. Here, they act as both predator and scavenger!

I'm going to take a break from posting #finfacts about #sharks and their relatives real quick and talk about something a LOT of people in #Australia discuss: "shark attacks" (or as I refer to them, shark bites/fatal shark bites thanks to @christopherneff paper).

Around 26 shark species have been identified as biting humans without provocation (floridamuseum.ufl.edu/fish/isaf/cont…). Of 22 are found in Australian waters. There are fatal unprovoked bites on humans in Australian waters (like many coastal countries).

There are many rankings of which #sharks are classified as "the most dangerous" and usually great white sharks, tiger sharks, and bull sharks make that list. All can be found in #Australia. They are all big, tend to be curious, frequent coastal environments, and are strong.

BUT!!!! Please remember that SHARK BITES ARE INCREDIBLY RARE EVENTS. Fatal shark bites? EVEN RARER. The AU Government Department of the Environment and Energy have some tips to lower your chances of a shark bite (scroll down): environment.gov.au/marine/marine-…

Emotions run high when these VERY RARE events happen and some have gone to great lengths- like culls. But culls kill more than just #sharks and since sharks are so migratory will most likely not get the "culprit." Many (public + scientists) against culls: nbcnews.com/news/world/no-…

Shark nets also kill more than just #sharks (telegraph.co.uk/news/2017/12/1…) and this fact constantly renews the debate if this protection method is the BEST method to protect Australian beaches. (Australia not only nation with shark nets, btw.)

Science has also concluded that shark nets are ineffective in stopping shark attacks and are really just there to provide a false sense of security. I agree that technology will be the best way to spot #sharks and alert beach goers abc.net.au/news/science/2…

Now back to some really cool #finfacts: introducing the mosaic skate(Pavoraja mosaica)! It's a skate found from the continental slope off Queensland, Australia at depths of up to 300-405 m. Reaching lengths of up to 28 cm, their diet and reproduction methods are unknown.

The longtail stingray (Dasyatis thetidis) goes by many multiple names, including the thorntail stingray and black stingray. They are seen swimming in southern African waters, Australia, and New Zealand to depths as deep as 440 m (1,440 ft), and like lagoons, estuaries, + reefs.

The Eastern Fiddler ray (Trygonorrhina fasciata) can be seen in this video: . These rays can be seen in eastern Australia up to 100 m deep and are fairly common in their range.

The black ghostshark (Hydrolagus homonycteris) is a large (reaching up to 101 cm in length), chimaera found off the continental slope and seamounts off south-eastern Australia between New South Wales, Victoria, Tasmania and Tasmania’s southern seamounts in 870-1450 metres (m).

Ogilby’s ghost shark (Hydrolagus ogilbyi) is found on the continental shelf and upper slope off south-eastern Australia (including Tasmania), they are observed at depths of 120-350 metres (m) and are probably found deeper. Off Tasmania, they are caught by commercial trawlers.

The adults of the Ogilby’s ghost shark (Hydrolagus ogilbyi) are difficult to distinguish from the Blackfin ghost shark (Hydrolagus lemures), and the two are often confused.

The giant black ghostshark’s scientific name is currently Hydrolagus cf. affinis, and has been called H. sp. D, a sister species to H. affinis which is known throughout the Atlantic. It seems to be widespread on deepsea slopes around southern Australia, Tasmania and New Zealand.

The cobbler wobbegong, Sutorectus tentaculatus, is the only member of their genus, Sutorectus! It's commonly seen around Western Australia, amongst rocky and coral reef habitat.

The blind shark (Brachaelurus waddi) are endemic to eastern Australia, and are commonly found along the bottom (mainly rocky or seagrass beds), from the intertidal down to 140 m (460 ft) deep. They can frequent tidal pools, and may become trapped from the receding tide.

Continuing! The zebra shark (Stegostoma fasciatum) is no more than 3.50 m (11.4 ft) long, it's was covered in black spots on a yellow background, a sharp contrast to the gray bodies of others.

The Dusky shark (Carcharhinus obscurus) is also known as the "bronze whaler," "black whaler," "brown dusky shark," "brown shark," "common whaler," and "shovelnose."

Dusky sharks look a lot like your "typical" shark in that they are almost torpedo-shaped. Their snout is a little shorter than most others and they have a low interdorsal ridge. They are blue-grey in color which fades into its creamy white underbelly.

The sawfish and saw shark (Pristiophorus Cirratus) often get confused, but are completely different animals (crazy how often that happens, eh?). #Australia has both!

In #Australia, up to five species of sawfish are found! You can learn about these animals here: finsunited.co.nz/bite-blog/sawf…

The saw shark has nine different species (although debated by some that it only has eight), found worldwide: Western Atlantic, Japan, Australia and South Africa.

The saw shark is known to forms schools; it has been hypothesized this is for hunting for food. More about them here: finsunited.co.nz/bite-blog/saw-…

Both the sawfish and saw shark have that chain-saw looking snout, however, SAW SHARKS HAVE BARBELS.

Purple Eagle Ray (Myliobatis hamlyni) is… well, as the name says: purple. Diet is unknown for these animals, but they are closely related to southern eagle ray (Myliobatis tenuicaudatus) so they may possibly share the same taste in prey.

Purple Eagle Ray (Myliobatis hamlyni) distribution is very poorly known, with only a few specimens being observed around Queensland, New South Wales, and Western Australia all the way up to Japan and Taiwan.

Speaking of rays, let's talk about @MotherOfRays who studies #flatsharks in #Australia! Her work is 1st comprehensive assessment of short-tail stingray pop of Jervis Bay, NSW. Primarily focusing their site use + interactions w humans in waterways of this popular coastal town.

Short-tail stingrays are also commonly referred to as smooth stingrays. They were formerly assigned to the genus Dasyatis; however, a recent taxonomic review reassigned this species to Bathytoshia.

You can read all about the amazing work @MotherOfRays does (and she's now doing PhD!!!) in #TFUI interview: finsunited.co.nz/bite-blog/ray-…

Another amazing #Australia scientist is Sasha Whitmarsh! Currently a PhD student at Flinders University in Australia who uses BRUVS. Read more about her here: finsunited.co.nz/bite-blog/arou…

Samantha Sherman, a PhD student at James Cook University in Townsville, #Australia is also using BRUVs in her research! You can read all about @SammSherman27 here: finsunited.co.nz/bite-blog/arou…

The zebra bullhead shark (Heterodontus zebra) is a common but very little known member of the Heterodontidae family (the same family as the Port Jackson shark).

The zebra bullhead shark (Heterodontus zebra) a bottom-dwelling shark, in a single genus, that has eight living species.

The zebra bullhead shark (Heterodontus zebra) live in subtropical shallow waters off in the western Pacific Ocean and Indian Ocean. They are usually around 50 m (164 ft) but in Australia are known to go way down under (haha, puns, hilarious) and hang at 150-200 m (495-660 ft).

The bowmouth guitarfish, also called the "shark ray" or "mud skate," is a species of ray and member of the Rhinidae family. The reason they’re called "guitarfish" is because they resemble the musical instrument… if it was underwater.

Fertilization in the bowmouth guitarfish is internal, usually giving live birth to four or five pups. Since they are slow to reproduce, they don’t recover quickly from the threats that constantly face them, and are therefore considered Vulnerable (V) by IUCN.

Although there are no major conservation efforts put into place for bowmouth guitarfish just yet, the TED devices used to get turtles out of harm’s way have helped a few bowmouth guitarfish escape nets. That’s something to be upbeat about (more guitar puns, yay).

#Finfact: In Australia, up to five species of sawfish are found and three of these, the largetooth sawfish, green sawfish and the dwarf/Queensland sawfish, are currently listed as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999.

Speaking of threatened species legislation, any listed threatened species can (and should) have a recovery action plan made in order to help the species recover.

Currently, Australia has recovery plans exist for these sharks.

-Grey Nurse Shark (Carcharias taurus)
-Sawfish and River Sharks (Multispecies Recovery Plan)
-Whale shark
-White shark

Now you may be thinking, "What about those freshwater elasmobranchs?" Good question! I haven't found any plans for them. #Finfact: Northern River shark and speartooth shark (Glyphis garricki and Glyphis glyphis) are found in northern #Australia.

Other protections I do know about? Well, the Australian government managed fisheries are prohibited to practice shark finning (definition: removing the fins and discarding the body of the shark at sea).

And while shark finning is banned in commercial fisheries in #Australia, some fisheries do allow for the harvest of the whole sharks (certain species). Once a #shark is landed, they may be processed (e.g. sale of their meat and fins and other shark byproducts).