Robbea seahi, Scharhauser & Saavedra & Pröts & Ot & Geier & Gruber-Vodicka & Polikarpov & Bourenkov & Leisch, 2025

Scharhauser, Florian, Saavedra, Daniel E. M., Pröts, Philipp, Ot, Jörg A., Geier, Benedikt, Gruber-Vodicka, Harald R., Polikarpov, Maxim, Bourenkov, Gleb & Leisch, Nikolaus, 2025, Revision of the genus Robbea (Stilbonematinae: Desmodoridae), worldwide abundant marine nematodes with chromophoric Fe-Br inclusions and the description of a new stilbonematine genus, Zoological Journal of the Linnean Society 203 (1), pp. 1-28 : 8

Robbea seahi sp.nov.

ZooBank registration: http://zoobank.org: urn:lsid:zoobank.org:act:5B3D9322-A4D5-44FB-8B55-B45FC258C271 .

Type location: Yakata , Okinawa, Japan; shallow subtidal sand. Coordinates: 26.4926 N, 127.842126 E.

Type material: One holotype ( NHMW-ZOO-EV-M-5871 ), three paratypes male ( NHMW-ZOO-EV-M-5872/1-3 ). Collection date: Dec. 2017. Collector: B. Seah.

Other material: Several specimens in J.A. Ott collection.

Etymology: The species is dedicated to Brandon Seah, marine scientist who collected the worms.

Description: With the characters of the genus. Measurements see Supporting Information, Table S2 .

Small (<6 mm long) and slender species ( Figures 10 and 11 ). Males with prominent, enlarged GSO in ventral post-pharyngeal region, protruding as 17–20 bumps. Subcephalic setae almost as long as cephalic setae. Cephalic capsule short, extending over about 50% of corpus. Corpus occupying about 25% of pharynx length, isthmus long (>60%), very small, round, glandular bulbus. Small somatic setae distributed over body. Tail conical with pointed tip. Symbiotic bacteria slender rods, 3,7 × 1.5 µm.

Figures

Figure 10. Robbea seahi sp. nov.. A, total view of holotype. B, pharynx region of holotype.C, tail region of paratype.Abbreviations:bulbus, b; corpus, c; cephalic capsule, cc; cephalic seta, cs; enlarged glandular sense organs, egso; fovea amphidialis, fa; gut, g; gubernaculum, gb; isthmus, i; subcephalic seta, scs; spiculum, sp; spinneret, spt; somatic seta, ss; testis, t; tail gland, tg.

Figure 11. Robbea seahi sp. nov.. A, anterior end of holotype, optical section. B, spicular apparatus of holotype. C, post-pharyngeal region of holotype. D, anterior end of paratype, surface view. E, pharynx bulbus of paratype. F, sperm in paratype.G, symbiotic bacteria on body surface. LM of preserved specimens.Abbreviations:bump, bu; corpus, c; cephalic capsule, cc; cephalic seta, cs; gubernaculum, gb; isthmus, i; ovary, ov; spiculum, sp. Scale bars: A, B, F, 15 µm; D, E, 10 µm; C, 25 µm; G, 15 µm.