Issue date April 30, 2018:
From Australia Post’s Stamp Bulletin:

The reef at Emily Bay, Norfolk Island is a popular spot for snorkelling, due to its clear water and an abundance of fish species.

The most predominant in terms of individual species are wrasses (Labridae) – a large and often brightly coloured family of fish that inhabit coral reefs and other temperate waters.

As each wrasse species has differing colour patterns across male, female and (sometimes) juveniles, from 17 species in the reef there are almost 50 spectacular colour variations.

The stamps in this issue, illustrated by renowned painter, naturalist and zoologist Roger Swainston, feature the vividly coloured adult male Surge Wrasse (Thalassoma purpureum) and the striking orange-red Luculent Wrasse (Pseudolabrus luculentus).