Peniagone vitrea Theel , 1882

Bribiesca-Contreras, Guadalupe, Dahlgren, Thomas G., Amon, Diva J., Cairns, Stephen, Drennan, Regan, Durden, Jennifer M., Eleaume, Marc P., Hosie, Andrew M., Kremenetskaia, Antonina, McQuaid, Kirsty, O'Hara, Timothy D., Rabone, Muriel, Simon-Lledo, Erik, Smith, Craig R., Watling, Les, Wiklund, Helena & Glover, Adrian G., 2022, Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean, ZooKeys 1113, pp. 1-110 : 1

Peniagone vitrea Theel, 1882

Fig. 47

Material.

Clarion-Clipperton Zone • 1 specimen; APEI 7; 5.0442°N, 141.8164°W; 4875 m deep; 28 May. 2018; Smith & Durden leg.; GenBank: ON400699 (COI), ON406622 (16S); NHMUK 2022.64; Voucher code: CCZ_077 .

Other material.

Pacific Ocean • 1 specimen, syntype of Peniagone vitrea var. setosa Ludwig ; South Pacific ; 0.6°S, 86.7667°W; 2418 m deep; Albatross Expedition; NHMUK 1895.11.12.7. • 3 specimens, syntypes of Peniagone vitrea Théel, 1882; East of St. Paul, Indian-Antarctic Ridge; 42.7167°S, 82.1833°W; 2652 m deep; Challenger Expedition, Stn. 302; NHMUK 1883.6.18.82 .

Description.

Single specimen. Body long, ~ 3 × as long as wide (Fig. 47C, D ). Mouth anterior, downwards; foremost neck-like part bent forwards in acute angle with ventral surface (Fig. 47C ); with ten tentacles of similar sizes; anus terminal. Velum consists of two pairs processes, fully fused by a membrane forming a lobe, with only the tips free; the two middle processes are much larger (Fig. 47A, B, D ). Eight pairs of tube feet surrounding the posterior third of ventral surface, decreasing in size distally. Skin translucent in live specimen (Fig. 47A, B ), but white, hard, and brittle after preservation, with numerous calcareous deposits (Fig. 47C, D ). Dorsal ossicles with four spinose arms, slightly arched, with mostly two long spinose processes (Fig. 47E ).

Remarks.

Morphological external characters and ossicle morphology are in accordance with the original description of Peniagone vitrea . Unfortunately, no genetic sequences of P. vitrea are available in public databases. This species was described from off Patagonia at 2652 m depth. Using data from Kremenetskaia et al. (2021), the COI sequence of P. vitrea is 16.5%-18.8% divergent (K2P) from other species of Peniagone , and 17.9% divergent from the COI sequence of P. leander generated in this study. In the phylogenetic tree, it is recovered in a well-supported clade with other species of Peniagone (Fig. 34 ).

Ecology.

The specimen was found feeding on the sedimented seafloor of an abyssal plain in APEI 7 at 4874 m.

Comparison with image-based catalogue.

A very similar Peniagone sp. morphotype (i.e., Peniagone vitrea sp. inc., HOL_059) has been commonly encountered in seabed image surveys conducted across nodule fields areas of the eastern CCZ (e.g., Amon et al. 2017b), but not in the abyssal areas surveyed within the Kiribati EEZ.

Family Laetmogonidae Ekman, 1926

Figures

Figure 34. Phylogenetic tree of the class Holothuroidea. Concatenated (12 S, 16 S, 18 S, 28 S, COI, and H 3) median consensus BEAST tree with posterior probability (PP) and bootstrap (BS) values indicated. Only values of PP> 0.70 and BS> 50 are shown, with values of PP> 0.95 and BS> 90 indicated with a circle. Nodes not recovered on the RAxML tree are indicated with a hyphen. Sequences generated in this study are highlighted in violet.

Figure 47. Peniagone vitrea Theel, 1882. Specimen CCZ _ 077: A, B in situ images C lateral view before preservation D dorsal view E dorsal ossicles. Scale bars: 2 cm (A); 3 cm (B); 200 μm (E). Image attribution: Durden and Smith (A, B); Wiklund, Durden, Drennan, and McQuaid (C, D); Bribiesca-Contreras (E)