Energetic potential of a diel vertical migration-mediated marine-to-terrestrial pathway: insights from myctophid fishes and the fishing bat Myotis vivesi

Diel vertical migration (DVM) structures pelagic food webs by bringing mesopelagic organisms into surface waters at night. Whether this recurrent prey pulse can also support transfers across the marine-terrestrial boundary has received less attention. Here, we combine empirical measurements of the energetic characteristics of two abundant Gulf of California myctophids, Benthosema panamense and Triphoturus mexicanus , with station-level biomass-density data from a published regional survey to characterize the potential energy represented by the vertically migrating prey field. Monthly mean biomass densities were calculated across eight stations, including zero catches, and the two monthly means corresponding to each season were then averaged. We integrate these survey-derived estimates with published dietary, molecular, and movement evidence for the fishing bat Myotis vivesi to evaluate how DVM may enable a recurrent pathway of marine-to-terrestrial biomass transport. Estimated prey-field energy density varied among species and seasons from 0.07 to 5.81 MJ per 1000 m 3 , primarily reflecting variation in biomass density while energetic density remained high across the analyzed samples. These values describe the energetic potential of a regional prey field rather than prey capture by bats or realized terrestrial deposition. Nevertheless, recurrent consumption of myctophids by M. vivesi , together with its return to coastal and island roosts, supports a biological pathway through which a fraction of mesopelagic-derived biomass can cross the marine-terrestrial boundary. This framework identifies DVM as the process that makes an energy-rich mesopelagic resource temporarily accessible to a terrestrial consumer while defining the measurements required to quantify the magnitude of transfer.