Duplominona uniserta Curini-Galletti n. sp.

(Fig. 8)

Holotype. Pacific Ocean: Gulf of Panama, off Isla Pacheca (Las Perlas Is., Panama)(Lat. 8°39’44.40”N; Lon. 79° 2’56.38” W), at a depth of about 4 m, shell hash, December 2011: one whole mount (USNM 1622599).

Etymology. The specific epithet refers to the morphology of the copulatory organ of the new species, provided with a single girdle (lat. sertum) of spines.

Description. A very slender species, about 2 mm long. Cephalic end with dot-shaped rhabdoids, and few clusters of long rhabdoids, also present in the pointed tail. With a short pharynx in front of midbody (Fig. 8 E).

Male genital system. With three testes in one row. With an extremely elongate seminal vesicle, about 200 μm long, provided with a thin muscular lining (Fig. 8 B, F: sv). Cirrus about 50 μm long, naked for most of its length, distally provided with one single girdle of seven spines, 3–5 μm long, distinctly hook-shaped, with a broad basis (Fig 8 C, D, G).

Accessory organ spherical, with a stylet 23 μm long. It opens to the outside with a pore nearly halfway between male and female pore.

Female genital system. Ovaria and vitellaria as in previous species. With a spherical bursa, close to the copulatory organ, and provided with a large vaginal pore, surrounded by glands (Fig 8 B).

Diagnosis. Species of Duplominona with a very elongate seminal vesicle and a single girdle of hook-shaped spines, 3–5 μm long.