Abstract: Lanternfish are vital to the deep-sea ecosystems, with considerable economic potential. We review the research progress on species diversity of lanternfish, the effects of seamounts and ocean currents on their species composition and distribution, as well as the diel vertical migration of lanternfish. To date, 256 species of lanternfish have been documented globally, classified into 2 families (Myctophidae and Neoscopelidae) and 37 genera. Among these, the Myctophidae comprises 34 genera and 250 species, with genus Diaphus (79 species) exhibiting the highest species richness. From the perspective of species diversity, the Pacific Ocean hosts the greatest number of lanternfish species (177), followed by the Indian Ocean (117), the Atlantic Ocean (89), and the Southern Ocean (11). Notably, the South China Sea and the East China Sea host 81 and 15 species of lanternfish, respectively. Seamounts increase the complexity of marine habitats, significantly influencing the spatial distribution and species diversity of lanternfish, and regulating their distribution by limiting the vertical migration depth and altering food supply. The structural complexity of ocean current zones, geographical latitude, and primary productivity levels collectively shape the diversity patterns of lanternfish. Upwelling boosts productivity, drawing lanternfish to aggregate, while fronts and topographic barriers shape their regional distribution. Species diversity of lanternfish peaks in tropical-subtropical seas (e.g., the Australian Current Zone), with regional differentiation driven by currents such as the Kuroshio and South Equatorial Counter Currents. Lanternfish are highly sensitive to mesoscale oceanic structures in their diel stratification behavior, with interspecific differences and regional heterogeneity in their response modes. Controlling factors include photoperiod, prey distribution, and ocean currents. This article would help enhance understanding of lanternfish and their roles in the deep-sea ecosystem and thus provide scientific support for their resource utilization.

Key words: Diaphus, species richness, diel vertical distribution, seamount, ocean current