ABSTRACT
Background: Mesopelagic fish specimens from two stations in the NW African Upwelling were identified and catalogued to produce a Darwin Core-aligned dataset. A total of 9655 individual fishes were identified, with 9017 specimens identified at least to genus level and 3124 specimens identified to species level. This dataset comprises specimens collected from the 1990 RRS Discovery (III) Cruise D195 and was used to investigate depth-related trends in diversity and community composition alongside species-specific migratory behaviour. The finalised dataset was published on OBIS through the Deep-Sea node. New information: This dataset contains occurrence and abundance data for midwater fishes caught between the Mauritanian coast and Cape Verde, published for the first time. The dataset records 146 different fish taxa. Twenty-three taxa in the dataset are not present in any prior OBIS datasets that cover the area. These novel taxa are: Bathylagusandriashevi, Bolinichthysindicus, Bolinichthyssupralateralis, Cyclothoneparapallida, Dolichopteroidesbinocularis, Gigantactis indet. Gymnoscopelus stet., Howellaatlantica, Hygophumproximum, Hygophumtaaningi, Ichthyococcuspolli, Lampadenaanomala, Lampanyctuscuprarius, Lampanyctusisaacsi, Lampanyctuslineatus, Lampanyctusmacdonaldi, Lampanyctusnobilis, Lestidiopsmirabilis, Loweinarara, Macroparalepisbrevis, Melamphaesmicrops and Melanonusgracilis. An anglerfish specimen belonging to Linophrynidae was also found, the first in the leftvent family to be logged in the area on OBIS; however, the specimen was too damaged to identify beyond this level.