The ruby seadragon is only the third kind of seadragon ever recorded, the other being the instantly recognisable leafy seadragon, which has a green and orange hue.
The first recorded specimen of the uniquely adorned creature washed up on Cottesloe Beach in 1919 and was until now thought to be a common seadragon, which has yellow and purple hues.
Through DNA sampling technology and research linking it to other specimens, it was shown in 2015 to be a new species.
The new images showed another striking difference, the ruby seadragon does not have leaf-like appendages that camouflage its fellow seadragons.
The researchers were also surprised to find that the ruby seadragon has a tail it may use to cling on to the rocks, to avoid being swept away by strong sea surges.
Common and leafy seadragons cannot bend their tails, which raises questions about the evolution of tails in this group of organisms, according to the researchers.