Question

what do many deep water organisms use for feeding and the attraction of mates

Answer 1

Let's talk about feeding first. Deep sea creatures have to have a slower metabolism, resulting in being able to survive with less oxygen. This helps them be months with out food. They need this because there is lack of resources int he deep sea. If they do eat, they usually eat organic materials that fall from above or other creatures.

Now about mating. Deep sea creatures usually use chemosynthesis to attract not only mates, but also prey. In biochemistry, chemosynthesis is the biological conversion of one or more carbon molecules and nutrients into organic matter using the oxidation of inorganic molecules or methane as a source of energy, rather than sunlight, as in photosynthesis

Now, what I told you is what they use for feeding or mating, but something that they use for BOTH feeding and attracting mates is bioluminescence. Bioluminescence is the production and emission of light by a living organism.

This might help: http://www.studystack.com/flashcard-943325