title: An ultrastructural study of the Antarctic calanoid Copepod Metridia gerlachei giesbrecht, 1902. Adult female.
abstract: Scanning electron microscopy (SEM) techniques can highly contribute to the knowledge of body structures in order to differentiate between different species or between varieties within the same species.  This is particularly important in extreme environments, such as in Antarctic waters, where the evolution efforts have promoted the development of endemisms.  In this work the external anatomy of Metridia gerlachei (Copepoda, Calanida) adult females, sampled during the Italian Oceanographic Campaign in Antarctica 1987-88, was described by SEM, particularly considering some swimming legs and the genital abdominal joint.  The descriptions already reported have been verified and some morphological details have been better emphasized.  As concerns the P2, the hook process of the first segment of endopod and a series of spines vaguely indicated, but not defined, in previous descriptions have been clearly evidenced.  In the P5 the occurrence of three well separated free segments and the location of a marginal sets have been shown.  The ultrastracture of the genital segment showed that a clear areola surrounds the genital field.
authors.affiliation: Dip. di Biologia Sperimentale, Ambientale ed Applicata, Sezione di Ecologia Applicata ed Educazione Ambientale, Università di Genova.
authors.forename: G L
authors.initials: GL
authors.lastname: Mariottini
authors.forename: M
authors.initials: M
authors.lastname: Feletti
authors.forename: P
authors.initials: P
authors.lastname: Romano
authors.forename: A
authors.initials: A
authors.lastname: Cadoni
authors.forename: A
authors.initials: A
authors.lastname: Carli
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D003445:Crustacea / Q000648:ultrastructure*; D005260:Female