Andyouthought - territorystories.nt.gov.au€¦ · canth’’, they reported in the journal...
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www.ntnews.com.au Saturday, January 18, 2014. NT NEWS. 47 PUB: NT NE- WS- DA TE: 18-J GE: 47 C LO- R: C M Y K ntnews.com.au l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l WEATHER ntnews.com.au l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l FISHING And you thought you were afraid of change The elephant shark gets its moniker from a trunk-like snout with which it rummages for crustaceans on the ocean floor A PREHISTORIC fish that in- habits the waters off southern Australia and New Zealand evolves even slower than the coelacanth, a famous ‘‘liv- ing fossil’’ whose DNA has barely changed over hun- dreds of millions of years, scientists say. The genome of the elephant shark ‘‘is evolving signifi- cantly slower than other ver- tebrates, including the coela- canth’’, they reported in the journal Nature. Known by its Latin name as Callorhinchus milii, the el- ephant shark gets its moniker from a trunk-like snout with which it rummages for crus- taceans on the ocean floor at depths of about 200 metres. Despite its name, the crea- ture is not a shark. Strictly speaking, it is a chi- maera, a small group of fish that diverged from sharks, rays and skates, called elas- mobranchs, about 420 million years ago. Both groups are ver- tebrates whose skeleton is made of cartilage. They split from bony vertebrates about 450 million years ago. Comparing the genomes of the elephant shark with that of humans and other ver- tebrates, the study found that the genetic code of C. milii is extremely compact, being less than a third that of humans. Its genome, they found, has evolved even less than that of the coelacanth — a rare fish found off South Africa that is such a success in its habitat niche that it has hardly had to change over nearly 400 million years. The genome could hold in- sights into how bones are for- med, which could help the fight against the bone disease osteoporosis. Elephant sharks, also cal- led Australian ghost sharks, grow to about 120cm in length. The fish is occasion- ally netted as by-catch by commercial trawlers but is not considered endangered.
Transcript of Andyouthought - territorystories.nt.gov.au€¦ · canth’’, they reported in the journal...
www.ntnews.com.au Saturday, January 18, 2014. NT NEWS. 47
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NTNE-WS-DA-TE:18-JGE:47 CO-LO-R: C-M Y-K
ntnews.com.au l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l lWEATHER
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And you thought youwere afraid of change
The elephant shark gets its moniker from a trunk-like snout with which it rummages for crustaceans on the ocean floor
A PREHISTORIC fish that in-habits the waters off southernAustralia and New Zealandevolves even slower thanthe coelacanth, a famous ‘‘liv-ing fossil’’ whose DNA hasbarely changed over hun-dreds of millions of years,scientists say.
The genome of the elephantshark ‘‘is evolving signifi-cantly slower than other ver-tebrates, including the coela-canth’’, they reported in thejournal Nature.
Known by its Latin name asCallorhinchus milii, the el-ephant shark gets its monikerfrom a trunk-like snout withwhich it rummages for crus-taceans on the ocean floor atdepths of about 200 metres.
Despite its name, the crea-ture is not a shark.
Strictly speaking, it is a chi-maera, a small group of fishthat diverged from sharks,rays and skates, called elas-mobranchs, about 420 millionyears ago.
Both groups are ver-
tebrates whose skeleton ismade of cartilage. They splitfrom bony vertebrates about450 million years ago.
Comparing the genomes ofthe elephant shark with thatof humans and other ver-tebrates, the study found thatthe genetic code of C. milii isextremely compact, being lessthan a third that of humans.
Its genome, they found, hasevolved even less than that ofthe coelacanth — a rare fishfound off South Africa thatis such a success in its habitatniche that it has hardlyhad to change over nearly400 million years.
The genome could hold in-sights into how bones are for-med, which could help thefight against the bone diseaseosteoporosis.
Elephant sharks, also cal-led Australian ghost sharks,grow to about 120cm inlength. The fish is occasion-ally netted as by-catch bycommercial trawlers but isnot considered endangered.
