There is many a unknown beastie that can be chance in the ocean . Not least   theworm goby ,   which   could legitimately pass as theChestburster monster’saquatic twin . But possibly one of the strangest is the shy and elusive giant sunfish ( orMola mola ) – the gentle giant of the animal kingdom .

One such specimen ground itself wash out up at the mouth of the Murray River in Coorong National Park , 80 klick ( 50 mile ) to the south of Adelaide , South Australia , where it was discovered by a crew of local fishermen drive along the sand .   Linette Grzelak , whose partner Steven Jones was one of the fisherman involve , post pictures of the ocean sunfish on Facebook .

" My partner was out with his oeuvre crew and he think it was a piece of shipwreck at first , " Linette   Grzelak toldGuardian Australia .

" I did n’t mean it was real until I Googled sunfish , " she toldBBC News , adding that Jones said the Pisces was " extremely heavy " with cutis " rough and leathery like a rhinoceros " .

Sunfish are the world ’s largest bony fish and can be get in temperate and tropic sea around the world . However , grant to Ralph Foster , the Pisces the Fishes collection manager at the South Australian Museum , it is rarified to spot ocean sunfish around these parts .

He says this especial individual was   a medium - sized creature , though sunfish have been bonk to reach   length of around   3.3 meter ( 11 feet ) – which is almost   the same size as a Volkswagon Beetle . They can also be pretty hefty , consider up to 2,250 kg ( around 5,000 pound ) , heavy than your average rhinoceros .

Size is not the only dimension that sets the sea sunfish apart . They curb the phonograph recording for develop more eggs in one sit down ( a jaw - dropping300 million ) than any eff craniate . Still , perhaps their most striking feature is their looking . Quite honestly , they look like a swimming brain . This is because , unlike most fish , their back fin does n’t grow . Rather , it folds back into itself , transform into a rounded rudder ( a clavus ) . Despite their rather freakish - looking appearance , they are not at all harmful   to humans .

This particular specimen is not the first sunfish to grab headlines latterly . Only at the get-go of the month , another species of sunfish ( Mola tecta)was foundsomewhere   unexpected – the Californian shore .