The ichthyofauna of four locations in the west Pacific were systematically accessed from bathyal to hadal depths: the Kermadec Trench, the New Hebrides Trench, the adjoining South Fiji Basin and the Mariana Trench. Bait-attending fish were recorded during more than 50 days of baited-lander bottom-time across 83 deployments, and 211 fish specimens across 84 trap deployments. Forty-seven fish categories were observed. Two fish families; the Synaphobranchidae and the Zoarcidae are added to those known to extend into the hadal zone. The Liparidae emerge as the dominant hadal fish fauna and two new species are discovered. Despite their isolation within their respective trenches, the endemic hadal liparids appear similar in morphology, feeding behaviour and optimum depth. Distinct fish fauna groups were identified: A bathyal group at < 3000 m in the New Hebrides and Kermadec trenches, an abyssal group (3039 – 4692 m) in the Kermadec Trench (and noticeably absent from the New Hebrides Trench), an abyssal-hadal transition zone (AHTZ) group (Kermadec: 4707 – 6068 m, Mariana: 4506 – 6198 m, New Hebrides: 2578 – 6898 m, South Fiji Basin: 4074 – 4101 m), and a hadal group of endemic snailfish in the Kermadec and Mariana trenches (6750 – 7669 m and 6831-8143 m respectively). The fish groups had distinct feeding strategies while attending the bait: The bathyal and abyssal groups were almost exclusively scavengers, the AHTZ group comprised predatory and generalist feeders, while the hadal snailfishes were exclusively predators. Observations of deep-sea fish in situ reveals behavioural observations never before recorded, confirming some hypotheses derived from morphology, and suggesting that fish behaviour at the bait may have an impact on the results of baited lander analysis.