Length 15.2 cms
Comments by Graham Short - "To differentiate Ornates vs Shaw's
in the field the head spines (on adults at least of both sexes)
tend to point backwards on Shaw's but forwards (or as a minimum
directly upwards) on Ornates.
I have found this feature very useful in field,
especially for females where the
'base' colours are quite similar in these species.
Even with males, in my earlier diving days I seemed to get so
distracted by the stunningly beautiful tail colours/markings that
I couldn't always remember what exact species I'd seen i.e. Shaw's
vs Ornate on a dive until I got my slides developed.
This seems amazing to me now as the males are so
obviously distinct but my experience suggests others will be
encountering similar problems until they've seen lots of these
fish of both sexes"
Colour pattern is different in the two sexes.
Male has blue spotting with the yellow network of narrow lines
separating the spots. The female has stripes.
Paired yellow and blue lines on snout, belly and cordal peduncle.
Tail with five blue loops. Body is very robust, about
pentagonal in cross section; deep keel in adults. Juveniles
smooth, rounded; developed ridges and spines with growth which
becomes very large in some females, but usually reduce in males
with age. Usually a double series of large spines over back,
starting above eyes. Some spines along lateral ridges.
Head profile has pointed snout which steepens in males, which
develop large hump in front of eyes. Moderate sized
triangular plates form very large hexagonal patterns, becoming
indistinct in large adults and covered with small tubercles.
Dorsal and anal fins short based.
The female bears numerous horizontal yellow and
blue lines on the body. the lines becoming wavy and
irregular in the upper parts of the side and the back. The
tail is plain.
Distribution - Western Australia, South
Australia, Tasmania, Victoria
Remarks - this is our commonest species and is
often found on beaches after storms.