Bathylagus

Bathylagus is a genus of deep-sea smelts, some species of which are noted for having stylophthalmine larvae.

==Species== The seven recognized, extant species in this genus are: Bathylagus andriashevi Kobyliansky, 1986 Bathylagus antarcticus Günther, 1878 (Antarctic deepsea smelt) Bathylagus euryops Goode & T. H. Bean, 1896 (goiter blacksmelt) Bathylagus gracilis Lönnberg, 1905 Bathylagus niger Kobyliansky, 2006 Bathylagus pacificus C. H. Gilbert, 1890 (slender blacksmelt) Bathylagus tenuis Kobyliansky, 1986 The oldest fossil species in this genus known from skeletal remains are from the Miocene. These include Bathylagus angelensis, whose remains are widespread across Southern California (Monterey Formation and Modelo Formation), as well as B. sencta, B. obesa, and B. toyohamaensis from Japan. These specimens are all known from formations that were formerly deposited in deep-sea environments, before being dramatically uplifted to the surface by geological activity. However, tentative fossil otoliths are also known from the Late Cretaceous (Maastrichtian) of the United States.