Bareskin Dogfish: I have an affinity with this dogfish. Little is known about how it works or the environment it inhabits. It is actually a shark and has so far only been found near Japan, along the Australian coast from about Brisbane to Hobart and in a relatively small area from Perth to the north.
Apparently they are dark in color with white-tipped fins, which suggest the pictured specimen above is either an albino or just a very crook sample.
According to what I could find out about them they have no anal fin (who would want one) and has grooved dorsal spines with the second larger than the first. It has a blunt nose, large eyes and large nostrils. It grows to a a maximum of about 45cm.
They are found in a depth range of 500m to 1200m.
It has litters of three to 22 pups.
And that is about where the information on this thing ends: No information on the reproductive cycle, no information on annual fecundity, gestation period, age at maturity or longevity.
From ugly ducklings like the Rough Dreamer to the kiss-me-I’m-really-a-prince Clown Triggerfish, Australia’s marine fishes are now at your fingertips thanks to FishMap.
FishMap is a free online mapping tool that anyone can use to find out which fishes occur at any location or depth in the waters of Australia’s continental shelf and slope. You can create species lists for any region that include photographs and illustrations, distribution maps and current scientific and common names.
FishMap has a million and one uses for everyday fish lovers, such as finding out which fishes occur at your local fishing spot, creating a personalised pictorial guide or identifying the fish you spotted during a dive. Researchers can examine the range of a threatened species, or figure out what occurs in a marine reserve. Commercial fishers can find out what fishes occur at different depths in the areas they fish, or even determine the possible species composition for catches of any fishery in the waters of Australia’s continental shelf and slope.
Australia’s marine biodiversity is among the richest in world, but before FishMap there was no easy way to generate illustrated species lists for any location you choose within Australia’s marine waters. It’s the only resource of its kind in the world that covers virtually all species of fish found in the marine waters of an entire continent.
The tool provides the scientifically known geographical and depth ranges of over 4500 Australian marine fishes – including our 320 sharks and rays. Searches reveal illustrated lists of fishes by area, depth, family or ecosystem. These lists can be printed to create simple guides or, if you really want to get serious about it, data can be downloaded into a spreadsheet for research.
FishMap is built on the Atlas of Living Australia’s open infrastructure, which is bringing Australia’s plants, animals and fungi from Australia’s biological collections to everyone.
The Atlas of Living Australia is an initiative of Australia’s museums, herbaria and other biological collections and is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy, the Super Science Initiative and the Collaborative Research Infrastructure Scheme.
FishMap will be officially launched on Tuesday 26 February 2013 and is available on the Atlas of Living Australia website: http://fish.ala.org.au
Media: Bryony Bennett. Ph: +61 3 6232 5261 MB: 0438 175 268 E: email@example.com
Sturgeon Whiptail: I was kicking back watching one of those fishing shows on TV the other day and they were somewhere in Canada catching sturgeon – and they were huge.
Think sturgeon. Think caviar.
So, does Australia have any of these? Nup. We have this thing above, but I have got to say they are a huge disappointment. Yeah I know – all creatures great and small – but this Whiptail just doesn’t cut it. They are actually part of the grenadier family and seem to be cashing in on the sturgeon name.
They grown to a maximum length of about 20cm and are found in depths of between 400m and 1300m off the northern Australian coast.
That’s about it – they are small and ugly.
The REAL sturgeons are bottom-feeders and are usually found in river deltas and estuaries. Some are entirely freshwater and a few venture into the open sea beyond near coastal areas. Several species of sturgeons are harvested for their roe, which is made into caviar.
Sturgeons appeared in the fossil record about 200 million years ago, around the very end of the Triassic, making them among the most ancient of actinopterygian fishes. True sturgeons appear in the fossil record during the Upper Cretaceous.
They are slow growing and can live to 100+ years and can grow to over 5m in length. They are partially covered with bony plates called scutes rather than scales. They also have four barbels – the feelers in front of their mouths – which don’t have any teeth. These are used to drag along the bottom to help them find food and navigate.
Now, THIS is a sturgeon!
By Ken Taylor, Research Scientist, CSIRO ICT Centre
If you’ve ever watched a professional bike race such as the Tour de France on TV, you might have thought to yourself: “Just how good are the professionals?” And if you do a bit of cycling yourself, you might be inclined to wonder: “How much better are they than me?”
Using data from the 2013 Tour Down Under – held in late January in and around Adelaide – I was able to compare the efforts of amateur recreational cyclists against those of professionals in the race.
Of the 6,500 cyclists that took part in the recreational event, 950 recorded their ride using the popular “social fitness” website Strava. I was then able to analyse this wealth of shared data to compare the efforts of amateur cyclists with the efforts of professional rider Serge Pauwels from the Omega Pharma-Quickstep team.
While German sprinter Andre Greipel won that Tour Down Under stage at the head of the peloton, Pauwels finished 42nd as part of the same group. This meant that Pauwels’s time was considered equal to that of Greipel’s.
As Pauwels remained in the peloton all day, riding conservatively, his effort represents the minimum needed to ride with the pros on a fast stage that averaged 41.5km/h.
So how did the non-pro riders perform over the same course?
While there could be a difference in the effort put in by pros and amateurs – for a start, the pros were racing and the public were not – many riders seem to have been giving it their best, particularly the faster amateurs.
The amateur riders also had to be motivated enough to turn up and choose the full 127km of Stage 4 rather than one of the shorter alternatives available on the day. This would suggest that the riders in question are all reasonably strong.
(If you didn’t ride in the Bupa Challenge you can get a rough idea of how you would have gone by comparing your average speed over a long ride to that of the amateur field below. You’d have to be able to average a punishing 26km/h including rest stops to make the top half of the amateur field in the Bupa Challenge Tour.)
The image above shows that Pauwels and the rest of the riders in the pro peloton were 4.4 standard deviations faster than the mean of everyone else and a full 5.7km/h faster than the quickest amateur.
How did they do it?
Well the obvious answer would be “they pedalled harder” but as it turns out, for the best of the amateurs, this isn’t the case.
A cyclist generates power to propel the bike forward, and this is measured by multiplying the force they exert on the pedals by how fast the pedals are rotating. Power is lost to air drag, rolling resistance and fighting gravity as they climb hills.
The heavier the cyclist, the higher the power they should be able to produce. As such, Serge Pauwels’s weight of 64kg makes his average of 223W more impressive than if he’d been, say, 80kg.
A cyclist can produce high power for short intervals but this will leave them tired. Each cyclist has a maximum amount of power they can produce over any particular interval. These best efforts can be shown in a curve compiled from their highest power over multiple efforts.
The image below compares Pauwels’s previously established best-effort power curve (dashed blue line) against his power curve for stage 4 (dashed red line) and the power curves of the four fastest amateurs (as per Strava) that had power meters during the Bupa Challenge Tour.
This image shows that Pauwels rode at his long-distance best but fairly conservatively – that is, he was well below his best over shorter intervals.
This conservative riding would have helped Pauwels stay fresh enough to achieve strong results in later stages of the six-stage tour. In turn, these strong results allowed him to finish the Tour Down Under in 20th place overall.
Three of the amateurs produced a higher average power than Pauwels, including one who recorded 243W – nearly 10% more than Pauwels’s 223W.
And one of the amateurs, “Spartacus Flying Scotsman”, was able to ride more conservatively (i.e producing less power in short intervals – see figure 3 above) while producing more power overall.
But Pauwels was more efficient, riding at a higher average speed from a lower average power than all of the amateurs.
Just how efficiently Pauwels rode can be seen by plotting speed against power, for all riders who uploaded power meter data to Strava (as seen in figure 4 below). Only 28 of the 950 riders used power meters and of these four were identified as unreliable and excluded.
The power required to overcome air drag is proportional to a rider’s velocity cubed (i.e. the drag increases dramatically the faster you go). And yet the power vs speed relationship for the amateurs is approximately linear.
This is unexpected, but because Pauwels is well below the trend, it emphasises just how efficiently he rode.
So, to keep up with the pros, the average Bupa Challenge rider needs to produce an additional 50W – an increase of a little more than a third – and ride much more efficiently to increase their speed by more than 50%.
And for the rest of us, matching the pros is an even more difficult task – most probably couldn’t ride 127km at any speed.
Ken Taylor has previously conducted cycling research funded through a CSIRO and AIS partnership. See http://www.csiro.au/en/Organisation-Structure/Divisions/Materials-Science–Engineering/CSIRO-and-AIS.aspx .
He works for CSIRO.
OK, this is not the most pleasant FFT picture we have had but it is interesting.
One of our regular FFT readers (and the winner of the inagural FFT identifcation quiz) Phillip Clark from Focus Fisheries in WA sent the pictures in. Phillip is a member of a fishing club and another member found the specimen on the flats of the Swan River in Perth.
Apparently there was a bit of debate among other members of the club as to what exactly had been found. There was an even split between those who thought it was an eel and those who had no idea. Finding the fish in the Swan River threw a few off them of track.
While we are not encouraging all and sundry to send in their pictures of fish they have found, I thought this one was strange enough to send on to our fish ID experts in Hobart.
John Pogonoski who works in fish taxonomy at CSIRO came up with the answer – “It’s Woodward’s Moray Eel, Gymnothorax woodwardi – described by McCulloch in 1912 – a common species in south-western WA (from about Cape Leeuwin north to about Shark Bay, inshore to at least 250m). I saw plenty of preserved specimens in the Western Australian Museum last year, so must be reasonably common.”
There you have it.
Ice cores drilled in the Greenland ice sheet, recounting the history of the last great warming period more than 120,000 years ago, are giving scientists their clearest insight to a world that was warmer than today.
In a paper published today in the journal Nature, scientists have used a 2540 metre long Greenland ice core to reach back to the Eemian period 115-130 thousand years ago and reconstruct the Greenland temperature and ice sheet extent back through the last interglacial. This period is likely to be comparable in several ways to climatic conditions in the future, especially the mean global surface temperature, but without anthropogenic or human influence on the atmospheric composition.
The Eemian period is referred to as the last interglacial, when warm temperatures continued for several thousand years due mainly to the earth’s orbit allowing more energy to be received from the sun. The world today is considered to be in an interglacial period and that has lasted 11,000 years, and called the Holocene.
“The ice is an archive of past climate and analysis of the core is giving us pointers to the future when the world is likely to be warmer,” said CSIRO’s Dr Mauro Rubino, the Australian scientist working with the North Greenland Eemian ice core research project.
Dr Rubino said the Greenland ice sheet is presently losing mass more quickly than the Antarctic ice sheet. Of particular interest is the extent of the Greenland continental ice sheet at the time of the last interglacial and its contribution to global sea level.
Deciphering the ice core archive proved especially difficult for ice layers formed during the last interglacial because, being close to bedrock, the pressure and friction due to ice movement impacted and re-arranged the ice layering. These deep layers were “re-assembled” in their original formation using careful analysis, particularly of concentrations of trace gases that tie the dating to the more reliable Antarctic ice core records.
Using dating techniques and analysing the water stable isotopes, the scientists estimated the warmest Greenland surface temperatures during the interglacial period about 130,000 years ago were 8±4oC degrees warmer than the average of the past 1000 years.
At the same time, the thickness of the Greenland ice sheet decreased by 400±250 metres.
“The findings show a modest response of the Greenland ice sheet to the significant warming in the early Eemian and lead to the deduction that Antarctica must have contributed significantly to the six metre higher Eemian sea levels,” Dr Rubino said.
Additionally, ice core data at the drilling site reveal frequent melt of the ice sheet surface during the Eemian period.
“During the exceptional heat over Greenland in July 2012 melt layers formed at the site. With additional warming, surface melt might become more common in the future,” the authors said.
The paper is the culmination of several years work by organisations across more than 14 nations.
Dr Rubino said the research results provide new benchmarks for climate and ice sheet scenarios used by scientists in projecting future climate influences.
Media: Craig Macaulay. Ph: +61 3 6232 5219 E: firstname.lastname@example.org
Astronomers using a CSIRO radio telescope have taken the Universe’s temperature, and have found that it has cooled down just the way the Big Bang theory predicts.
Using the CSIRO Australia Telescope Compact Array near Narrabri, NSW, an international team from Sweden, France, Germany and Australia has measured how warm the Universe was when it was half its current age.
“This is the most precise measurement ever made of how the Universe has cooled down during its 13.77 billion year history,” said Dr Robert Braun, Chief Scientist at CSIRO Astronomy and Space Science.
Because light takes time to travel, when we look out into space we see the Universe as it was in the past — as it was when light left the galaxies we are looking at. So to look back half-way into the Universe’s history, we need to look half-way across the Universe.
How can we measure a temperature at such a great distance?
The astronomers studied gas in an unnamed galaxy 7.2 billion light-years away [a redshift of 0.89].
The only thing keeping this gas warm is the cosmic background radiation — the glow left over from the Big Bang.
By chance, there is another powerful galaxy, a quasar (called PKS 1830-211), lying behind the unnamed galaxy.
Radio waves from this quasar come through the gas of the foreground galaxy. As they do so, the gas molecules absorb some of the energy of the radio waves. This leaves a distinctive “fingerprint” on the radio waves.
From this “fingerprint” the astronomers calculated the gas’s temperature. They found it to be 5.08 Kelvin (-268.07 degrees Celsius): extremely cold, but still warmer than today’s Universe, which is at 2.73 Kelvin (-270.42 degrees Celsius).
According to the Big Bang theory, the temperature of the cosmic background radiation drops smoothly as the Universe expands. “That’s just what we see in our measurements. The Universe of a few billion years ago was a few degrees warmer than it is now, exactly as the Big Bang Theory predicts,” said research team leader Dr Sebastien Muller of Onsala Space Observatory at Chalmers University of Technology in Sweden.
“A precise and accurate determination of the cosmic microwave background temperature at z=0.89″, by S. Muller et al. Accepted for publication in the journal Astronomy & Astrophysics; online at http://arxiv.org/abs/1212.5456
MEDIA: Helen Sim Ph: +61 2 9372 4251 E: email@example.com
By Andrea Wild
No, the problem is not ghost ships on the high seas, but ghostnets. Lost and abandoned fishing gear drifts around the world’s oceans and can continue fishing for decades.
With around 640,000 tonnes of fishing gear lost or discarded each year, ghostnets are a huge problem worldwide. Originating mainly from fisheries and Asia and Australia, ghostnets in Australia’s Gulf of Carpentaria are among the highest concentration in the world and are threatening our marine turtles. During a recent cleanup of ghostnets on beaches in the Gulf, 80 per cent of animals found trapped in nets were marine turtles, including Olive Ridley, Hawksbill, Green and Flatback turtles.
Using a model of ocean currents and data collected by Indigenous rangers on the number of ghostnets found during beach cleanups, the scientists simulated the likely paths ghostnets take to get to their landing spots on beaches in the Gulf of Carpentaria.
Combining this with information about the occurrence of turtles in the area, they found that entanglement risk for turtles is concentrated in an area along the eastern margin of the Gulf and in a wide section in the southwest extending up the west coast.
The research pinpoints where prevention and clean-ups can really make a difference to protecting our biodiversity.
Ghostnets, originating mainly from fisheries in Asia and Australia, are a particular problem in Australia’s Gulf of Carpentaria, where they can reach densities of up to three tonnes/km, among the highest recorded worldwide.
“Our research goes beyond discovering where ghostnet fishing is taking place, to actually estimating its impact on biodiversity, in particular on threatened marine turtles,” Dr Denise Hardesty of CSIRO said.
“Using a model of ocean currents and data collected by Indigenous rangers on the number of ghostnets found during beach cleanups, we simulated the likely paths ghostnets take to get to their landing spots on beaches in the Gulf of Carpentaria.
“Combining this with information about the occurrence of turtles in the area, we found that entanglement risk for turtles is concentrated in an area along the eastern margin of the Gulf and in a wide section in the southwest extending up the west coast.
“Most ghostnets enter the Gulf from the northwest and move clockwise along its shore. This means we can help protect biodiversity in the region by intercepting nets as they enter the Gulf, before they reach the high density turtle areas along south and east coastlines.”
Ghostnets are a global problem, capturing seabirds, marine mammals and sea turtles worldwide. Lost or abandoned fishing gear makes up only 20 per cent of marine debris but has a disproportionate effect because it is designed to capture wildlife.
“Our research shows that combining models of marine debris with species occurrence data could identify global hot spots for impact, helping pinpoint where prevention and clean-ups could really make a difference to biodiversity,” Dr Hardesty said.
This research used information on ocean currents generated by the BLUElink Ocean Data Assimilation System to simulate the paths of ghostnets.
Media: Andrea Wild. Ph: +61 2 6246 4087 Mb: 0415 199 434 E: firstname.lastname@example.org
Originally posted on Solar @ CSIRO:
In today’s Newcastle Herald newspaper our blogger Dr Greg Wilson appeared in an article about our cool next generation solar cells made from dyes. We’ve previously shown you how they are made. Greg’s also holding one in the picture below.
We are developing dye-sensitised solar cells (DSC) that can be integrated into the walls, windows and roof top materials of buildings. They need to cover a much larger area to generate the same amount of electricity as the common silicon photovoltaic panel. We can make our DSC pretty colours; one day bill boards and signs might also be made of them (how cool!).Solar@CSIRO blogger, Greg Wilson holding a dye-sensitised solar cell at the CSIRO Energy Centre in Newcastle. In the background you can see an entire wall made up of the cells. This installation was the largest of its kind back in 2003 when the Centre was built, and…
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Leaning toward a Banded Sweep but not really sure. Anyway, sweeps are grey, often with a tinge of blue, green, or sometimes brown. They both like to get together in schools and are found from the southern coast of New South Wales, around the south of the country and north to the central coast of Western Australia.
The Sea Sweep can grow to about 61cm in length (the one above is just a bit shy of that….) while the Banded Sweep is a bit smaller.
They are found on rocky reefs in coastal waters. Young sweeps hang out in small schools inshore, and the larger adults school in small groups in open waters, often in turbulent areas on coastal reefs to 25m deep.
They’re big, powerful and fast. Top to bottom, they measure about half the Galaxy’s diameter. They contain as much energy as a million exploding stars. And they are roaring along at 1000 kilometres a second (yes, a second).
Revealed by our Parkes radio telescope (aka The Dish): they are giant geysers of charged particles shooting out from the centre of our Galaxy.
The finding is reported in today’s issue of Nature.
“These outflows contain an extraordinary amount of energy — about a million times the energy of an exploding star,” said the research team’s leader, CSIRO’s Dr Ettore Carretti.
But the outflows pose no danger to Earth or the Solar System.
The speed of the outflow is supersonic, about 1000 kilometres a second. “That’s fast, even for astronomers,” Dr Carretti said.
“They are not coming in our direction, but go up and down from the Galactic Plane. We are 30,000 light-years away from the Galactic Centre, in the Plane. They are no danger to us.”
From top to bottom the outflows extend 50,000 light-years [five hundred thousand million million kilometres] out of the Galactic Plane.
That’s equal to half the diameter of our Galaxy (which is 100,000 light-years — a million million million kilometres — across).
Seen from Earth, the outflows stretch about two-thirds across the sky from horizon to horizon.
So how could we have missed them before?
A couple of reasons. The particles are glowing with radio waves, rather than visible light, so seeing the geysers depends on having a telescope tuned to the right frequency (which happens to be 2.3 GHz). And the Galactic Centre is a messy, confusing place where a lot is going on.
VIDEO: Ettore Carretti talks about how the telescope makes maps of the sky.
Our Galaxy has a black hole at its centre, but it’s not that which is powering the geysers. Instead it’s star-power: “winds” from young stars, and massive stars exploding.
About half of all the star-formation that goes on in our Galaxy happens in and near the Galactic Centre. That’s a lot of stars, and a lot of energy.
VIDEO: The Parkes telescope observing as night falls and stars come out and the Milky Way appears overhead. Credit: Alex Cherney / terrastro.com
MEDIA: Helen Sim. Mb: 0419 635 905. E: email@example.com
Southern RockLobster: I know its not a fish but it is getting close to Christmas and a lot of people will be eating one of these in between slinging insults across the lunch table. Who knows? Maybe some small, retained facts from this post can calm the situation before the flaming brandy is tossed toward Uncle Phil from Newcastle.
They are a species of spiny lobster found throughout coastal waters of southern Australia and New Zealand including the Chatham Islands.
They resemble lobsters (look HERE for difference), but lack the large characteristic pincers on the first pair of walking legs. They are carnivorous and like to feed during the night. They live in and around reefs at depths ranging from 5m to 200m.
Adults are sexually mature at between seven and 11 years. Eggs develop on females, which carry between 100,000 and 500,000 eggs which are fertilised and held below the tail on hairs on the female’s abdomen. The eggs develop there for up to five months. The eggs then metamorphose into larva which leave the female and are free swimming plankton which migrate towards the surface.
Not sure if there will be FFT next week – will see how I am going before heading off for small holiday. Anyway, thanks for reading FFT and have a good Christmas.
An innovative global observing system based on drifting sensors cycling from the surface to the ocean mid-depths is being celebrated by scientists today after reaching a major milestone – one million incredibly valuable ocean observations.
From 10 drifting robotic sensors deployed by Australia in the Indian Ocean in late 1999, the international research program has been quietly building up a global array which is now enabling new insights into the ocean’s central influence on global climate and marine ecosystems.
The initial objective was to maintain a network of 3000 sensors, in ice-free open ocean areas, providing both real-time data and higher quality delayed mode data and analyses to underpin a new generation of ocean and climate services. The program is called Argo.
“We’re still about 50 years behind the space community and its mission to reach the moon,” says Argo co-Chair and CSIRO Wealth from Oceans Flagship scientist, Dr Susan Wijffels.
“The world’s deep ocean environment is as hostile as that in space, but because it holds so many clues to our climate future exploring it with the Argo observing network is a real turning point for science.
“In its short life the Argo data set has become an essential mainstay of climate and ocean researchers complementing information from earth observing satellites and uniquely providing subsurface information giving new insights into changes in the earth’s hydrological warming rates and opening the possibility of longer term climate forecasting,” Dr Wijffels said.
Although the one millionth profile of the upper ocean, measured from the surface to a depth of two kilometres, was achieved in early November, oceanographers around the world are today celebrating this critical benchmark in ocean monitoring which delivers data to a scientist’s desk within 24 hours of sampling.
Celebrations included a series of high-level international presentations by senior scientists involving Dr Wijffels, her Argo co-Chair Prof Dean Roemmich from Scripps Institution of Oceanography, oceanographer Dr Josh Willis from the NASA Jet Propulsion Laboratory, and Dr Jim Cummings from the US Naval Research Laboratory.
The Argo array has risen to now number more than 3500 sensors, the largest there has ever been. The average lifetime of the floats has improved in the past decade greatly increasing the efficiency of the operation.
Presently 28 countries contribute to the annual A$25M cost of operating the program. The US is the largest provider of sensors to the network, with Australia, led by CSIRO with the Integrated Marine Observing System and the Bureau of Meteorology, maintaining more than 300 profilers for deployment mainly in the Indian and Southern Oceans, and Tasman Sea.
The 1.5 metre tall robotic sensors cycle vertically every 10 days, sampling temperature and salinity. At the surface, the sensors despatches its data via satellite to national centres across the globe, where analysts then check it, package it and send it to synchronous assembly centres in France and the US. The sensor’s ascent and descent is regulated by a hydraulic pump, powered with lithium batteries. Their life expectancy is between 4-9 years, averaging more than 200 profiles per sensor as they drift with the currents and eddies.
Data are collected at the impressive rate of one profile approximately every four minutes, (360 profiles per day or 11000 per month) and on 4 November 2012 Argo passed the symbolic milestone of collecting its one millionth profile. To put this achievement in context, since the start of deep sea oceanography in the late 19th century, ships have collected just over half a million temperature and salinity profiles to a depth of 1km and only 200000 to 2km. At the present rate of data collection Argo will take only eight years to collect its next million profiles.
Dr Wijffels said almost 1200 scientific papers based on or incorporating Argo data have been generated since the start of the program. Prominent findings include:
- Analysis of ocean salinity patterns that suggests a substantial (16 to 24%) intensification of the global water cycle will occur in a future 2° to 3° warmer world.
- A more detailed view of the world’s largest ocean current, the Antarctic Circumpolar Current.
- An insight into changing bodies of water in the Southern Ocean and the way in which carbon dioxide is removed from the atmosphere.
- Isolating the effect of ocean warming and thermal expansion on the global energy and sea level budget.
Dr Wijffels said Argo data is now also being widely used in operational services for the community, including weather and climate prediction and ocean forecasting for environmental emergency response, shipping, defence, and safety at sea.
Media: Craig Macaulay Ph: +61 3 6232 5219 Mb: 04199 966 465 E: Craig.Macaulay@csiro.au
(Disclaimer – These are the words of others and I will not be held responsible for any offense.)
Old Wife: It has a deep and compressed body and concave forehead. The name – old wife – refers to the sound caused by it grinding its teeth when caught (or the Old Man comes home from the pub smelling of grog and cheap perfume).
It has the same features as other butterfly fish but the old wife is easily distinguished by its silver-and-black, vertical zebra-striped coloration, and by its two large dorsal fins. The dorsal fins have bony, knife-like spines. These have no obvious venom groove nor gland but the spines are widely considered to inflict a painful venom.
The fish grows up to 50 cm long and is found in the temperate waters around Australia.
It is one of the earliest fish described in Australian. In 1790, John White in his Journal of a Voyage to New South Wales originally named it the long-spined chaetodon.
In 1836, closely related fossils were found in Europe. The well preserved fossils show the basic body plan and even the zebra pattern of colouring have not changed significantly over the past 50 million years.