Schooling of the vertically migrating mesopelagic fish Maurolicus muelleri in light summer nights

Abstract

Vertically migrating Maurolicus muelleri arrested their nocturnal ascent below the peak zooplankton concentrations during Light summer nights at 62 degrees N. At 69 degrees N, the behavior was further modified, with M, muelleri forming schools in the upper layer at night. We suggest that M. muelleri used schooling as an antipredator strategy due to the absence of dark periods.