Scientists have finally reeled in a colourfully named fish famous for scales and difficulty to catch.

The 'Blue Bastard' fish has been hooked by experts with the Queensland Museum, with the newly discovered fish previously something that had been confused with a different animal and only mentioned in fishermen's tales.

The fish had been the subject of local legend, dubbed the 'blue bastard' by anglers across northern Australia because of its bluish sheen and the degree of difficulty involved in catching one.

Scroll down for video

Queensland Museum scientists have discovered the colourfully named 'Blue Bastard' fish

Plectorhinchus caeruleonothus is a species of sweetlip living on the shallow reefs in the country's north that had remained unrecognised by science until now.

A Weipa fisherman emailed Queensland Museum Ichthyologist Jeff Johnson a picture of a slippery specimen last year.

It prompted him to team up with geneticist Jessica Worthington Wilmer to analyse comparative specimens from as far afield as Africa, the Middle East and Japan, using their DNA sequence codes to describe the newest member of the sweetlip family.

Mr Johnson said it was unusual the fish's notoriety took so long to extend beyond the fly-fishing community.

A young 'Blue Bastard'. The fish gets its name because of the way it changes colour, and how difficult it is to catch

'It's quite a unique fish in both biology and behaviour, so in a way it's surprising it took this long for it to be officially recognised as a new species,' he said.

The 'blue bastard' can grow to one metre in length.