<P> The Summary Report of the HMS Challenger expedition lists radiolaria from the two dredged samples taken when the Challenger Deep was first discovered . These (Nassellaria and Spumellaria) were reported in the Report on Radiolaria (1887) written by Ernst Haeckel . </P> <P> On their 1960 descent, the crew of the Trieste noted that the floor consisted of diatomaceous ooze and reported observing "some type of flatfish" lying on the seabed . </P> <P> "...And as we were settling this final fathom, I saw a wonderful thing . Lying on the bottom just beneath us was some type of flatfish, resembling a sole, about 1 foot long and 6 inches across . Even as I saw him, his two round eyes on top of his head spied us--a monster of steel--invading his silent realm . Eyes? Why should he have eyes? Merely to see phosphorescence? The floodlight that bathed him was the first real light ever to enter this hadal realm . Here, in an instant, was the answer that biologists had asked for the decades . Could life exist in the greatest depths of the ocean? It could! And not only that, here apparently, was a true, bony teleost fish, not a primitive ray or elasmobranch . Yes, a highly evolved vertebrate, in time's arrow very close to man himself . Slowly, extremely slowly, this flatfish swam away . Moving along the bottom, partly in the ooze and partly in the water, he disappeared into his night . Slowly too--perhaps everything is slow at the bottom of the sea--Walsh and I shook hands . </P> <P> Many marine biologists are now skeptical of this supposed sighting, and it is suggested that the creature may instead have been a sea cucumber . The video camera on board the Kaiko probe spotted a sea cucumber, a scale worm and a shrimp at the bottom . At the bottom of the Challenger deep, the Nereus probe spotted one polychaete worm (a multi-legged predator) about an inch long . </P>

Who went to the deepest part of the ocean