Horizontal and vertical distribution patterns of larval myctophid fishes in the Kuroshio Current region

Abstract

The horizontal and vertical distribution of myctophid fish larvae is described based on discrete depth sampling from the surface down to 200 m at seven stations on a transect crossing the Kuroshio Current on 6–9 July 1977. A total of 7819 larvae was collected. Myctophid larvae accounted for 72% of the total fish larvae and included 18 species or types belonging to 12 genera. Based on horizontal distribution patterns these species (or types) were categorized into three groups, i.e. Kuroshio‐axis group (Myctophum asperum, M. orientale, Lampadena luminosa and Symbolophorus evermanni), Kuroshio east group (Hygophum reinhardtii, Lampanyctus alatus, Diogenichthys atlanticus, Lobianchia gemellarii, M. nitidulum, Benthosema suborbitale, Lampadena sp. and Ceratoscopelus warmingii) and Pan‐ Kuroshio group [Diaphus stubby type (mostly D. garmani) and D. kuroshio]. Larvae of the subfamily Lampanyctinae were distributed in shallower (0–30 m) waters than those of the subfamily Myctophinae (50–150 m), while this relationship was opposite of the night‐time depth distribution of adults of the two subfamilies.