Love child of the deep blue ocean
■ A fish which has taunted Northern Australian anglers has been scientifically labelled a literal “bastard” to catch.
The fish’s scientific name is Plectorhinchus caeruleonothus, with caeruleo meaning blue and nothus, bastard, due to its notoriety as a difficult target species among the fly fishing community in WA and Cape York, Queensland.
The blue bastard is a species of sweetlip, often confused for a painted sweetlip. It is common across the north of the country which was identified by Queensland Museum ichthyologist Jeff Johnson after a Weipa fisherman Ben Bright sent him a few photos.
Mr Johnson said Mr Bright then caught four adult specimens on fly over a few months to be used for DNA analysis against comparative species from elsewhere in the world.
“DNA sequences of numerous other sweetlip species from Australia, Indonesia, Japan, East Africa and the Arabian Sea were obtained from various sources, especially an international database of DNA codes,” he said.
“In addition to this a large number of proportional measurements, and counts of features such as scales, fin spines, gill rakers and teeth, were made from 17 preserved museum specimens found in fish collections in Perth, Darwin and Hobart.”
The blue bastard grows up to one metre in length and is a solitary fish which engages in aggressive “kissing” with male rivals which will lock jaws in prolonged struggles. Like the painted sweetlip, the blue bastard is greyish in colour as an adult and undergoes a transformation losing the colourful patterns of its juvenile stage as it gets older.
Where the blue bastard differs, though, is in the dorsal fin spines where the painted sweetlip has nine or 10 compared with the former’s 12.
The blue bastard likes shallow flats near rocky or coral outcrops surrounded by sand and can be found from the Ningaloo Reef through to Exmouth and the Dampier Archipelago.
About 30 new species of fish are officially described by ichthyologists from Australian waters every year.
Mr Johnson said there were still many new undescribed species out there in the big blue.
“Especially in remote areas of the north,” he said. “Many will be small, cryptic, or look similar to other already known species.”
An adult blue bastard.