Deep-sea fish from the open ocean

...these fish are thought to have adapted to the deep sea from the continental shelf to the seabed along the shelf slope in relatively recent times. While such deep-sea fish are collectively called continental shelf deep-sea fish, the mesopelagic and deep-sea benthic fishes mentioned in the first half of this article, including the cod, deep-sea eels (a type of cave conger eel), burrowing fish, lizardfish, green lizardfish, lizardfish, and pelagic fish, are collectively called pelagic deep-sea fish, since they generally live at depths of 200 meters or more, that is, in the open ocean offshore from the continental shelf.
[occurrence]
Many deep-sea fish spend their juvenile stage in the surface layer, less than 200 meters below sea level.

*Some of the terminology that refers to "pelagic deep-sea fish" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…そこでこれらの魚は比較的新しい時代に陸棚から陸棚斜面の海底沿いに深海に適応したと考えられている。このような深海魚を陸棚性深海魚と総称するのに対し，前半で述べた中･深層遊泳性魚類や深海底生性魚類のうちソコダラ類，深海性ウナギ類(ホラアナゴの1種)，ソコギス類，トカゲギス類，アオメエソ類，シンカイエソ類，チョウチンハダカ類は，その仲間全体が通常200m以深，つまり陸棚より沖合の外洋に生息するという意味で外洋性深海魚と総称される。
［発生］
　深海魚には稚仔魚（ちしぎよ）の時期を200m以浅の表層で過ごすものが多い。…

※「外洋性深海魚」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報