Aglaona valdesi Chaban & Ekimova & Schepetov & Chernyshev 2022, SP. NOV.
Creators: name: Chaban, Elena M.
name: Ekimova, Irina A.
name: Schepetov, Dimitry M.
name: Chernyshev, Alexei V.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Cephalaspidea
Aglajidae
Aglaona
Aglaona valdesi

description: AGLAONA VALDESI SP. NOV.
(FIGS 1, 5)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 076EBBFA-C017-46B1-8C19-505F60E9CAE3
Type specimens: Holotype: ZIN 62696, Kuril Islands, Pacific slope of the Kuril Islands near the Bussol Strait, SokhoBio expedition, R / V Akademik M.A. Lavrentyev, Cruise 71, station 9–7, 26 July 2015, 46˚16.2΄N 152˚03.1΄E, depth 3374 m (sequenced). Paratypes: ZIN 62463, SokhoBio, station 9–7, one specimen (dissected, sequenced); ZIN 42464, SokhoBio, station 9–7, one specimen (sequenced); ZIN 62697, SokhoBio, station 9–7, two specimens; ZIN 62698, SokhoBio, station 9–9, 27 July 2015, 46˚15.7΄N 152˚03.1΄E, depth 3580 m, one specimen.
Type locality: Kuril Islands, Pacific slope of the Kuril Islands near the Bussol Strait, 46˚16.2΄N 152˚03.1΄E, depth 3374 m.
Diagnosis: Headshield truncated at its posterior end; apex with one whorl visible; spiral sculpture with chains of narrow elongated pits of equal height. Head copulatory system with large conical penial papilla armed with a small triangular chitinous plate.
Description: Preserved specimens up to 5.3 mm long, c. twice as long as wide. Body white, almost completely retracted into shell. Headshield short, rectangular, rounded anteriorly and truncated posteriorly, c. onefifth of body length. Parapodia small; foot short, extending to half of shell length. Parapodia and foot strongly contracted.
Shell internal, white, semitransparent, occupying entire posterior shield, 4 mm long and c. 3 mm wide in the largest paratype. Spire consisting of a body whorl, covered with callus. Shell oval, wider anteriorly, widest in the middle of body whorl, apex obtuse. Periphery of body whorl regularly oval. Aperture not protruding beyond apex. Outer lip thin, fragile. Parietal wall convex, covered with a wide, wing-shaped callus; columellar border of inner lip straight, covered with narrow callus. Growth lines weak, frequent; spiral sculpture consists of thin, frequent chains of shallow, narrow, elongated pits of equal height connected with narrow grooves.
Buccal bulb muscular, with chitin lining inside and developed radular sac posteriorly; salivary glands short. Radular formula 13 × 2:1:0:1:2. Laterals large, hook-shaped, bearing small denticles on internal border; marginal small, hook-shaped, without denticles. Cephalic penial complex with large, elongated, penial sheath and a short, thick, convoluted prostate; prostate almost equal in length with penial sheath; penis consisting of large, conical papilla and small, triangular chitinous plate.
Comparison: Aglaona valdesi differs from A. rudmani in the head shape (truncated at its posterior end in A. valdesi vs. triangular in A. rudmani) and penial armature (a microscopic triangular plate in A. valdesi vs. a large stylet with additional cusps in A. rudmani) (Table 4).
Distribution: Kuril Islands, Pacific slope of the Kuril Islands near the Bussol Strait, at 3374 m depth.
Etymology: This species is named for Dr Ángel Valdés for his contributions to malacology in general and to cephalaspidean research in particular.
description: Published as part of Chaban, Elena M., Ekimova, Irina A., Schepetov, Dimitry M. & Chernyshev, Alexei V., 2022, The new genus Aglaona: the first abyssal aglajid (Heterobranchia: Cephalaspidea: Aglajidae) with a description of two new species from the north-western Pacific Ocean, pp. 198-214 in Zoological Journal of the Linnean Society 196 on pages 206-208, DOI: 10.1093/zoolinnean/zlab115, http://zenodo.org/record/7035284