Sawfish
Sawfishes, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish with some species reaching lengths of about . They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes.
Snailfish
In October 2008, a UK-Japan team discovered a shoal of "Pseudoliparis amblystomopsis" snailfish at a depth of approximately in the Japan Trench. These were, at the time, the deepest living fish ever recorded on film. The record was surpassed by a snailfish that was filmed at a depth of in December 2014 in the Mariana Trench, and extended in May 2017 when another was filmed at a depth of in the Mariana Trench. The species in these deepest records remain undescribed, but it has been referred to as the "ethereal snailfish". The deepest-living described species is "Pseudoliparis swirei", also of the Mariana Trench, which has been recorded to . In general, snailfish (notably genera "Notoliparis" and "Pseudoliparis") are the most common and dominant fish family in the hadal zone. There are indications that the larvae of at least some hadal snailfish species spend time in open water at relatively shallow depths, less than .