Draconema ophicephalum Claparede 1863

• Main Authors: Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2016
• Subjects: Biodiversity; Taxonomy; Animalia; Nematoda; Adenophorea; Desmodorida; Draconematidae; Draconema; Draconema ophicephalum; karelia*; karelian; White Sea
• Online Access: https://doi.org/10.5281/zenodo.5628340; http://treatment.plazi.org/id/03F17E4CFF8BFFC7FF30FC4DFE815A39

Draconema ophicephalum (Claparède, 1863) Figs 1–3, Table 2 (morphometrics) Material. Ten males and ten females. Locality. White Sea (Northern Russia), Karelian Coast of the Kandalaksha Bay, vicinity of the White Sea Biological Station, Velikaja Salma Strait between the Veliky Island and Kindo Peninsula (66°33'N, 33°06'E), depth 2–5 m, brown and red algae. 18–27 August 2013. Description. Body swollen in the middle of pharyngeal region and strongly narrowed just posteriorly at the level of cardia and anterior-most intestine. Male bodies slightly slimmer than that of females. Most specimens bent dorsally in anterior half of the body. Female body noticeably widened in region of the reproductive organs. Body cuticle distinctly annulated along the entire body, thicker in the pharyngeal region and thinner posterior to the cardia. Anterior-most head cuticle smooth, forming rostrum. Length of the rostrum 15–39 µ m in males and 17–33 µ m in females. Anterior 12–14 cuticular annules of the pharyngeal region enlarged (three annules in 10 µ m) and marked with tiny irregular vacuoles along the midline of each annule while remaining posterior annules of the body are 2–3 times more narrow (8–9 annules in 10 µ m) and look homogeneous. Small mouth opening covered with six rugose lips. Labial region encircled with a tight and narrow hexagonal furrow and then with a wider radially rugose (crumpled) zone (Fig. 3 D). Six short (4–5 µ m) inner labial setae situated in the furrow. Six outer labial setae 5–6 µ m long located at the outer margin of the rugose zone. Four cephalic setae 16–18 µ m long located at level of anterior edge or middle part of amphideal fovea. Numerous somatic (subcephalic) setae on the rostrum mask cephalic setae, hence the cephalic setae may be difficult to distinguish. Amphideal fovea situated at the base of the rostrum in latero-dorsal position. Amphideal fovea large, loop-shaped, dorsal arm slightly longer than ventral, with no difference in shape between males and females. Width of the amphideal fovea ...