Similar to the family Argentinidae the larvae are slender, with straight gut extending beyond midpoint of body. Whereas head of Argentinidae larvae is relatively small, Bathylagidae larvae have moderate to large heads (Ahlstrom et al., 1984b).
Eye shape and structure taxonomically important in bathylagid larvae. Eyes sessile in Bathylagus argyrogaster (Bathylagus argyrogaster) and Bathylagus longirostris, stalked in Bathylagus antarcticus (Bathylagus antarcticus), Bathylagus. bericoides, Bathylagus euryops, Bathylagus gracilis (Bathylagus gracilis), Bathylagus greyae and Bathylagus tenuis (Bathylagus ?tenuis) (Ahlstrom et al., 1984b; Olivar et al., 1993).
Pattern of melanophores on ventral trunk is main pigmentation feature useful in identification of these families (Ahlstrom et al., 1984b). Larvae of bathylagid species may have large isolated melanophores along ventral trunk as in Bathylagus antarcticus, Bathylagus euryops, and Bathylagus gracilis, or linear series of smaller melanophores as in Bathylagus argyrogaster, Bathylagus bericoides, and Bathylagus longirostris (Ahlstrom et al., 1984b, Olivar et al., 1993).
Table Osmeriformes
22 geographic zones