Symmetriapelta wareni Beck, 2023

Chen, Chong & Sigwart, Julia D., 2023, The lost vent gastropod species of Lothar A. Beck, Zootaxa 5270 (3), pp. 401-436 : 429

Symmetriapelta wareni Beck , sp. nov.

Figs 18 , 19

[ZooBank LSID: urn:lsid:zoobank.org:act:9D3FF7B3-B4E6-48B4-B3AA-5DB26555EC88 ]

Type material. Holotype [MNHN-IM-2000-38693], two paratypes in MNHN [Paratype 1: MNHN-IM-2000- 38694; Paratype 2: MNHN-IM-2000-38695], two paratypes in NSMT [Paratype 3: NSMT-Mo 79429; Paratype 4: NSMT-Mo 79430], two paratypes in SMF [Paratype 5: SMF 370390 ; Paratype 6: SMF 370391 ].

Type locality. North Fiji Basin (White Lady) .

Material examined. The type material and BIOLAU, BL03,> 10 specimens [MNHN-IM-2020-12946]; BIOLAU, BL04,> 10 specimens and 3 empty shells [ SMF 370392 ]; BIOLAU, BL08, 9 specimens [NSMT-Mo 79431]; BIOLAU, BL09, 1 specimen [ SMF 370393 ]; BIOLAU, BL12,> 10 specimens [NSMT-Mo 79432]; STARMER II, PL10, 4 specimen [ SMF 370394 ]; STARMER II, PL11, 7 specimens [MNHN-IM-2020-12947]; STARMER II, PL12,> 10 specimens [NSMT-Mo 79433]; STARMER II, PL13, 5 specimens [ SMF 370395 ]; STARMER II, PL14, 2 specimens [ SMF 370396 ]; STARMER II, PL15, 1 empty shell [ SMF 370397 ]; STARMER II, PL20, 4 specimens [ SMF 370398 ]; No data, 4 specimens [ SMF 370399 ] .

Distribution. North Fiji Basin and Lau Basin at hot-vent fields.

Etymology. Species is named after Anders Warén, Swedish Museum of Natural History, Stockholm.

Description. The characters defining the genus also serve as the description of the species. In addition, the following characters are worth mentioning:

Shell ( Figs. 18 , 19B ). Shell surface with three to five beaded, fine, radial riblets alternating with thicker, beaded radial ribs; these thicker ribs are extremely variable as comparison of Fig. 18A with Fig. 18E shows. There are both character states present at North Fiji and Lau vents with all possible states of transition.

Dimensions. Largest specimen length 5.7 mm, width 4.1 mm, height 1.8mm; Holotype 3.9 mm x 2.6mm x 1.5 mm.

Figures

FIGURE 18. Symmetriapelta wareni gen. et sp. nov. A–C. Paratype 1 (shell length 4.0 mm). A. Dorsal view. B. Viewed from right. C. Shell interior; anterior on the left. D–E. Holotype (shell length 4.1 mm). D. Ventral view. E. Dorsal view. F.A specimen from BIOLAU, BL03 (shell length 2.2 mm) with extremely thick radial ribs; calcareous layers partly dissolved, ventral view.

FIGURE 19. Symmetriapelta wareni gen. et sp. nov. A. Paratype 2 (body length 3.1 mm; shell fragmented), animal removed from shell, in dorsal view. B. Critical point dried specimen in ventral view. C–D. Radula. C. Overview. D. Half-row of radula teeth, arrows indicate nubs on the bases of first and second lateral teeth. [Scale bars: B, 1 mm; C, 50 μm; D, 20 μm.]