Confirmed by Marine Pests - Agriculture Vic that this is not the invasive D. vaxillum, but likely to be a native species of Didemnum.
So many! I have never even seen two together before
Pope's Eye Reef Life Survey Dive
IDing the sea slug
Reef Life Survey dive (Lonsdale Kelp Outer)
IDing the shark
not sure if this is a member of the sea slug grouping for this survey