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The pictures #1 and #2 were originally posted at these websites as Hypselodoris bullockii (Collingwood, 1881).
It looks very similar to Hypselodoris sp. 8 in IPN at page 268:
Gosliner, Terrence M., David W. Behrens & Ángel Valdés. 2008. Indo-Pacific Nudibranchs and Sea Slugs. Sea Challengers Natural History Books.
Gig Harbor, Washington. 426 pp.
Pretty similar are:
Hypselodoris bullockii which differs by the pale pinkish background colour, and by thin white marginal band,
Hypselodoris sp. 08 which differs by the colour of the gills,
Hypselodoris sp. 10 which differs by the dark blueish-purple colour of the rhinophore clubs.
Hypselodoris apolegma which differs by the purple colour, and by the reticulate white edging of the mantle.
Thorunna halourga which differs by the broad white mantle margin, and by the low gill pocket.
This picture shows a specimen mating Hypselodoris sp. 08, this indicates they are most probably the same species, I keep them seperate for now.