bathypelagic
Concise Oxford English Dictionary © 2008 Oxford University Press:
bathypelagic /ˌbaθɪpɪˈladʒɪk/
▶adjective Biology (of fish and other organisms) inhabiting the sea at a depth of between about 1,000 and 3,000 metres (approximately 3,300 and 9,800 ft), where it is dark and cold.
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