Characteristics of the habitat for larval development of three bathylagid fish species (Pisces: Salmoniformes)

Abstract

Three bathylagid smelt species were identified: Bathylagus ochotensis Schmidt 1938, Bathylagus wesethi Bolin 1938 and Leuroglossus stilbius Gilbert 1890. A structure analysis of the copepod community was also carried out at the sampling stations and 55 species of copepods were identifíed. The copepod species Calanus pacificus Brodsky 1948, Acartia danae Giesbrecht 1889 and Labidocera trispinosa Esterly 1905 were dominant where B. ochotensis was found. The dominant copepod species where B. wesethi was found were C. pacificus, Corycaeus speciosus Dana 1848 and Paracalanus parvus Claus 1863. The copepod species C. pacificus, Pleuromamma abdominalis Lubbock 1888 and Rhincalanus nasutus Giesbrecht 1888 were found with L. stilbius. Both B. ochotensis and B. wesethi were found in the California Current, whereas L. stilbius occurred in moditied California Current waters. The biogeographic affinities of the copepod species were mainly tropical-equatorial, temperate and transitional, and a different habitat was determined for each bathylagid species based on these biogeographic affinities. It can, therefore, be inferred that distinct ecological conditions exist for each species in the study area.