( They ( ( ( are usually ) ( found ( in ( ( ( ( ( ( the ( sunlit zone ) ) ( of ( the ( water column ) ) ) ) , ) ( ( ( less ( than 200 ) ) metres ) deep ) ) , ) ( sometimes ( called ( the ( ( ( epipelagic or ) photic ) zone ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (ADVP (RB usually)) (VP (VBN found) (PP (IN in) (NP (NP (DT the) (JJ sunlit) (NN zone)) (PP (IN of) (NP (DT the) (NN water) (NN column))) (, ,) (ADJP (NP (QP (JJR less) (IN than) (CD 200)) (NNS metres)) (JJ deep)) (, ,) (VP (ADVP (RB sometimes)) (VBN called) (NP (DT the) (ADJP (JJ epipelagic) (CC or) (JJ photic)) (NN zone))))))) (. .)))
They are usually found in the sunlit zone of the water column, less than 200 metres deep, sometimes called the epipelagic or photic zone.
(ROOT (S (NP (DT The) (JJ photic) (NN zone)) (VP (VBZ extends) (ADJP (NP (CD 200) (NNS meters)) (JJ deep))) (. .)))
The photic zone extends 200 meters deep.