Unciherpia hirsuta García-Álvarez, Urgorri & Salvini-Plawen, 2001

Cobo, M. Carmen, Farris, William J. & Kocot, Kevin M., 2024, New data on the biodiversity of Solenogastres (Mollusca, Aplacophora) in the Mediterranean Sea: findings from the program “ Our Planet Reviewed ” Corsica 2019 - 2022, Zoosystema 46 (21), pp. 543-576 : 568-570

Unciherpia hirsuta García-Álvarez, Urgorri & Salvini-Plawen, 2001

Unciherpia hirsuta García-Álvarez, Urgorri & Salvini-Plawen, 2001: 114 .

MATERIAL EXAMINED. — Corsica (France) [4 specimens] • 1 specimen (used for sclerite preparations, histology, and DNA extraction); CORSICABENTHOS 3 ( Table 2 ); 122 m depth;MNHN-IM-2019-18279; GenBank: OQ600031; OQ597875 (1 microscope slide with sclerites, 1 SEM stub; 4 slides with 5 µm serial sections) • 3 specimens (preserved in 95% ethanol); CORSICABENTHOS 3 ( Table 2 ); 122 m depth; MNHN-IM-2019-18282, MNHN-IM-2019-18283, MNHN-IM-2019-18284.

DESCRIPTION

Animals with elongate body (10-15 mm × 0.8-2 mm), without keels or protuberances and with the anterior region wider than the posterior. White to yellow with a strongly hirsute appearance ( Fig. 4D ). With hollow acicular sclerites: long straight acicular sclerites (200-300 × 5-6 µm) ( Fig. 9G ); acicular sigmoid sclerites (120-160 × 5-7 µm); straight and long sclerites with harpoon-shaped distal end (360-520 × 8-14 µm) ( Fig. 9F ); serrated acicular sclerites (230-300 × 8-10 µm) only in the anterior half of the body; and hook-shaped sclerites (150-180 × 7-9 µm) ( Fig. 9 H-I). With one type of knife-shaped scales of the pedal groove (75-85 × 12 -14 µm). Mouth opening at the posterior end of the atrial cavity. Without radula. With 16 circum-pharyngeal subepithelial follicular glands ( Fig. 14A ).

REMARKS

Within Pruvotinidae , the subfamily Unciherpiinae García-Álvarez, Urgorri & Salvini-Plawen, 2001 is characterized by the absence of a radula and by having circum-pharyngeal follicular glands instead of ventrolateral foregut glands ( García-Álvarez et al. 2001; García-Álvarez & Salvini-Plawen 2007; Pedrouzo et al. 2022) ( Table 4 ). The three genera in this subfamily, all of which are represented by a single described species, can be differentiated based on the sclerites. Uncimenia Nierstrasz, 1903 and Unciherpia have harpoon-shaped and hook-shaped sclerites, but the hook-shaped sclerites lack an apical prominence in Uncimenia . Sialoherpia Salvini-Plawen, 1978 lacks hook-shaped sclerites and has solid, acicular sclerites ( Salvini-Plawen 1978; García-Álvarez et al. 2001). The specimen from Corsica was identified as Unciherpia hirsuta based on the external aspect and sclerites ( García-Álvarez et al. 2001: fig. 1; Pedrouzo et al. 2014: fig. 2). In addition, this identification was confirmed by the study of the internal anatomy: common atrio-buccal cavity, 16 follicular glands surrounding the pharynx ( Fig. 14A ), midgut with a short, paired rostral caecum, respiratory folds and one dorso-terminal sensory organ ( García-Álvarez et al. 2001; Pedrouzo et al. 2014).

The known geographical distribution of U. hirsuta includes several localities near the type locality (NW Iberian Peninsula) ( García-Álvarez et al. 2001; Pedrouzo et al. 2019) and the Alboran Sea (Mediterranean Sea) ( Pedrouzo et al. 2014). The Atlantic specimens were found at depths between 760 and 1499 m ( García-Álvarez et al. 2001; Pedrouzo et al. 2014) while the specimen collected in the Alboran Sea was found at a greater depth (349-365 m) ( Pedrouzo et al. 2014). The specimens from Corsica were collected at 122 m in sandy bottoms, which corresponds in terms of habitat with previous localities in which the species was found ( García-Álvarez et al. 2014).

Figures

FIG. 4. — Habitus of A, Tegulaherpia cf. myodoryata (photo of the living animal – MNHN-IM-2019-16176); A’, Tegulaherpia cf. myodoryata (photo of the preserved specimen – MNHN-IM-2019-16176); B, Eleutheromenia sierra (Pruvot, 1890) (photo of the preserved specimen – MNHN-IM-2019-1749); C, Pruvotia cf. sopita (photo of the preserved specimen – MNHN-IM-2019-1744 – on Sertularella sp.); D, Unciherpia hirsuta García-Alvarez, Urgorri & Salvini-Plawen, 2001 (photo of the living animal – MNHN-IM-2019-18279); E, Simrothiella margaritacea (Koren & Danielssen,1877) (photo of the preserved specimen – MNHN-IM-2019-18280). Scale bars 1 mm. Symbols: arrow, copulatory stylets; stars, anterior end of the animals.

FIG. 9. — Sclerites of A-E, Eleutheromenia sierra (Pruvot, 1890) (MNHN-IM-2019-1749): A, light microscopy image of the cuticle (the dorsal keel); B, general view of the sclerites in the dorsal region of the body; C, closer view of the hook-shaped sclerites and acicular sclerites in the dorsal region of the body (arrow, thin sclerites; star: longer and thicker sclerites); D, detail of the hook-shaped sclerites; E, acicular sclerites in the ventral region of the body; F-I, Unciherpia hirsuta (MNHN-IM-2019-18279): F, hook-shaped and harpoon-shaped sclerites (star, harpoon-shaped sclerites); G, acicular sclerites in the ventral region of the body; H, I, hook-shaped sclerites. Scale bars: A, 200 µm, B-I, 20 µm.

FIG. 14. — Histological sections of A, Unciherpia hirsuta (MNHN-IM-2019-18279): circumpharyngeal glands and B, Dorymenia vagans (MNHN-IM-2019-18271): copulatory stylets; C-E, Anamenia gorgonophila (MNHN-IM-2019-18270): C, anterior foregut region; D, radular region; D’, detail of the radula, radular sac and ventrolateral foregut glands; E, oblique section of posterior region with abdominal spicules visible on the animal’s right side. Abbreviations: see Material and methods. Scale bars: 100 µm.