Way down deep

Is marine life everywhere? When the bathyscaphe Trieste made it to the bottom of the Challenger Deep in the Marianas Trench, more than 11 kilometers down, in 1960, the pilots reported a flatfish moving over the bottom. Most authorities doubt this: they suggest it was a holothurian (sea cucumber). But it was LIFE.
The Japanese Shinkai 6500 holds the depth record for an untethered craft carrying humans, almost 7km down. About 6.6 km down it spotted a colony of clams, a new record for that species. Later, on a dive to the same depth, it found polychaete worms 20cm long.
Then in 1995 Japan's robotic explorer, Kaiko, went back to the deepest spot in the oceans. Where the Triests had its encounter, Kaiko's lights showed a seas slug, a worm, and a shrimp. The deepest fish documented remains a 15-cm specimen from the Puerto Rico Trench in the Atlantic, almost 9 km down.
What's left to discover down there? Scientists used to think no multicelled animal could live under the pressures in the great ocean trenches. Now they all look forward to finding many more.