Nansenia oblita, also called the forgotten argentine (from the specific name oblita, "forgotten") or the Mediterranean large-eyed argentine, is a species of fish in the pencil smelt family (Microstomatidae).
Nansenia oblita is silvery in colour. Its length is maximum . It has 10 or 11 dorsal soft rays, 9 or 10 anal soft rays, 28âÂÂ30 gill rakers, 42âÂÂ45 vertebrae, and 4 branchiostegal rays. The proximal part of the adipose fin is unpigmented and its entire body is covered with guanine. The base of the caudal and procurrent caudal-fin rays are pigmented.
Nansenia oblita is pelagic, living in the northwest and eastern Atlantic Ocean, western Mediterranean Sea and Adriatic Sea at depths of . It is commonly found off Messina, Sicily.
It spawns during winter in the Mediterranean, perhaps later in the Atlantic. It lays spherical eggs of about diameter. It feeds on zooplankton.