Descripción de algunas estructuras de interés taxonómico en Nansenia (Pisces, Microstomatidae)

Resumen

Description of some structures with taxonomic usefulness in Nansenia (Pisces, Microstomatidae)
Nansenia genus has not yet been satisfactorily defined. In this work the operculars, the lateral line scales and the crumenal organ of N. iberica, N. oblita, N. atlantica, N. crassa, N. ardesiaca and N. tenera are described as well as the caudal skeleton of N. iberica. Operculars and scales fit into a common pattern, different from the Bathylagus one; yet they all have specific and distinctive characters. The genus Nansenia shows two types of crumenal organs, one of them is similar to the one described in N. oblita by Greenwood & Rosen in (1971) and the other differs from it by presenting an uncinate process in the fourth epibranchial. The above mentioned characters may be useful to both a future redefinition of the genus Nansenia and to distinguish the species studied in this work.