Robbea weberae sp.nov.

ZooBank registration: http://zoobank.org: urn:lsid:zoobank.org: act: 00CF1524-8B96-40F2-8A40-EC4AEC20BD99.

Type location: Bay of Sant’ Andrea, Elba, Italy; subtidal sand in 5–6 m depth. Coordinates: 42.808342N, 10.141764 E.

Type material: One holotype (NHMW-ZOO-EV-M-5866), five paratypes male (NHMW-ZOO-EV-M-5867/1-5), two paratypes female (NHMW-ZOO-EV-M-5868/1-2). Collection date: April 2016. Collector: F. Scharhauser.

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

Etymology: The species is dedicated to Miriam Weber, scientist and our host at the Hydra Marine Station, Elba.

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

Large (L> 7mm), extremely slender (a> 200) species, females with much shorter tail than males (Figures 6 and 7). Post-pharyngeal ventral GSO enlarged but not protruding. Cephalic capsule extending over 55–60% of corpus. Corpus about 25% of pharynx length, isthmus 60–63%, bulbus 13–17%. Cuticle extremely finely striated, striae 0.4 µm wide. Vulva strongly cuticularized. Tail conical with rounded tip. Symbiotic bacteria rods, 2.3–2.6X1 µm.