Morphology of Soboliphyme baturini (Dioctophymatida, Nematoda) by SEM and histological sectioning

Abstract Specimens of Soboliphyme baturini (Dioctophymatoida), collected from martens in Alaska, were investigated by scanning electron microscopy (SEM) and histological sections. Soboliphyme species are recognized by their large oral sucker, which is a muscular organ made of radial and longitudinal musculature. A ring of 6 papillae is present on the outer side of the oral sucker, as well as an individually variable pattern of additional papillae. Papillae are also present in a roughly longitudinal line along the body. We document the histological anatomy of the nervous system, the cervical sacs, pharynx and intestine, the musculature, the mesenteries and the reproductive organs. Several characters documented from S. baturini are proposed as apomorphies of Dioctophymatida: the anterior position of the brain ring, the presence of cervical sacs and the presence of two extracellular and four muscular mesenteries connecting the intestinal system to the body wall.