Pucker up (Image: Queensland Museum)
Only in Australia. An elusive and aggressive blue fish, until now known only through seafarers鈥� tales, has finally been documented by science. So hard to catch, the fish had become known to anglers as 鈥渂lue bastard鈥� 鈥� a name it is now officially stuck with.
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Its Latin name is Plectorhinchus caeruleonothus. 鈥�Careleo is blue. And nothus is bastard,鈥� says from Queensland Museum in Brisbane, Australia, who described the fish for the first time. 鈥淚t鈥檚 an affectionate turn of phrase,鈥� he says.
The blue bastard is a member of the sweetlips family, so-called because of their pouting, fleshy lips.
Johnson had heard of the fish before, but it wasn鈥檛 until he received two good quality photographs of one from the town of Weipa in Queensland that he knew they might really exist.
鈥淲hen I looked at them I was immediately able to distinguish them,鈥� he says. There were 12 dorsal spines, whereas similar known fish have only ten, he says.
鈥淚 said to the fisherman, if you can come up with some specimens I鈥檒l do some analysis and describe it as a new species,鈥� says Johnson. 鈥淗e set about catching them. It took him a couple of months. He came up with four specimens.鈥� Johnson then examined fish in museums and collections and found a total of 17 specimens that had been misidentified as other species.
Aggressive kissing
Johnson used DNA barcoding, where a small distinctive part of the genome is investigated, to reveal that the blue bastard is a completely distinct species, not even in the same genus as the similar-looking painted sweetlips, which it had been mistaken for.
Because they prefer shallow murky water, Johnson says identifying the species has been tricky.
But they appear to exist widely across the north of Australia from Cape York on the tip of Queensland to Ningaloo reef off the coast of Western Australia, hanging out in shallow, murky water, and feeding on small crustaceans like larval shrimps and crabs.
People who had sighted the fish had also described seeing them 鈥渒issing鈥�. 鈥淏ut it couldn鈥檛 be anything further from the truth,鈥� says Johnson. 鈥淚t鈥檚 actually quite a combative behaviour between rival males for territory. It鈥檚 a behaviour unique to this species.鈥� They appear to lock jaws with one another, and struggle against each other until one fish gives up.
We all look different in baby photos (Image: Queensland Museum)
As the fish grow they completely transform. They start life with stripes that become finer and finer until they disappear. An adult fish can be around a metre in length.
Journal reference: Zootaxa, DOI:
