White with red spots and a yellow margin, and one of the most photographed nudibranchs on the east coast.
Between about 3.5 and 5 cm; sources disagree. A broad oval mantle, bright lemon yellow to white, scattered with large purple-red spots, with a yellow or orange band around the mantle margin and an orange band on the rear edge of the foot. The gills are numerous and feathery and the rhinophores are purple-red, paler at the base. The oral tentacles are conspicuous.
The field call is spots against net. This animal has discrete, well-separated round red spots on yellow. The related red-reticulate animals have a red network covering the mantle instead. Even that check may not resolve to species: a 2020 study found this species sits inside the red-reticulate complex, which contains at least five species-level lineages, most of them still undescribed. So the name is currently accepted and the boundaries are not.
It eats sponges and stores their chemical defences, which is what the bright colouring advertises. It lives on temperate and subtropical rocky reef between the surface and about 25 m, concentrated on the Australian east coast. Records from further afield in the Indo-Pacific are exactly what the 2020 study calls into question and should not be repeated as fact.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
