Shinkaiya contorta Gooday & Holzmann, 2017

Holzmann, Maria, Barrenechea-Angeles, Inés, Lim, Swee-Cheng & Pawlowski, Jan, 2024, New xenophyophores (Foraminifera, Monothalamea) from the eastern Clarion-Clipperton Zone (equatorial Pacific), Zootaxa 5419 (2), pp. 151-188 : 172

Shinkaiya contorta Gooday & Holzmann, 2017

Figs 11 , 12

Shinkaiya contorta Gooday & Holzmann, 2017 , in Gooday et al. 2017c, p. 727 –730, Fig. 2A–F .

Material examined. BC004 RC0160 (morphology and genetics). Sequenced isolates: 21448, 21449.

Description. The shipboard photographs show a single plate-like fragment with an intact semicircular margin and concentric ‘growth lines’ clearly developed over parts of the surface ( Fig. 11A ). It was originally attached to a nodule and the lower margin was broken when it was removed from the substrate. The plate was strongly undulating so that it did not lie in one plane. It was still largely intact when seen in Geneva, where it measured 44 mm in maximum dimension. By the time it reached Southampton, the fragment had broken into several smaller pieces, some almost flat but others curved, and the largest with a maximum dimension of about 15 mm ( Fig. 11B ). They are greyish, with a smooth surface, in places overlain by patches of lighter material resembling fine-grained sediment. ‘Growth lines’ are sometimes visible. The wall is 60–95 µm thick, in a few places up to 115 µm ( Fig. 11D, E ; 12E ), quite soft, delicate, and very fine-grained with a scattering of darker flecks.

The test interior is occupied mainly by masses of stercomare ( Fig. 12C–F ), some of which are attached to the underside of the wall. On detached wall fragments the stercomare forms distinctive strands, typically 50–105 µm in width, that branch and usually anastomose to varying degrees, sometimes forming dense networks ( Fig. 12C–E ). Granellare strands are whitish, typically 45–75 µm in width and weave between the stercomare. A granellare tube is not clearly visible under stereomicroscope.

Remarks. The wavy, plate-like morphology of the preserved fragment is consistent with that of the unique holotype of Shinkaiya contorta from the UK-1 area of the CCZ ( Gooday et al., 2017c). This was an intact specimen, with a maximum dimension (46 mm), similar to that of the new specimen, but with a more complex structure that comprised a number of curved, plate-like elements, often with well-developed growth lines. The soft, finely agglutinated test wall, and the reticulated stercomare branches, are similar but some other test features are different. Particularly notable is that the plate itself, and particularly the wall of the plate, are much thinner (about 0.5–1.0 mm and 60–95 µm, respectively) than those of the type specimen (1.3–2.0 mm and 270–500 µm, respectively). Nevertheless, sequences obtained from the new fragment confirm its identification.

Figures

FIGURE 2. Aschemonella monilis Gooday & Holzmann 2017. A–D, Sequenced specimens. A, Dark specimen attached to nodule; RC1056 (BC026). B, Interior of test fragment with red granellare (after removal of most pieces for sequencing) and dark stercomare; RC0056 (BC001). C, Fragment with two segments; RC0490B (BC010).D, E, RC1900.1 (BC045). D, Fragment with broken segment containing granellare. E, Detail of dome and tubular apertural structure. F, G, Specimens without cytoplasm; RC1900.2 (BC045). F, Complete fragment. G, Detail of apertural structures. No scale is available for B.

FIGURE 11. Shinkaiya contorta Gooday & Holzmann 2017; Specimen RC0160 (BC004).A, Shipboard photograph of fragment. B–E, Laboratory photographs. B, Collection of fragments. C, Broken fragment showing interior. D, Detail of broken fragment with exposed interior. E, Complete fragment. E, Section of test exposed on broken surface.

FIGURE 12. Shinkaiya contorta Gooday & Holzmann 2017; Laboratory photographs; specimen RC0160 (BC004). A, Exterior of fragment. B, Broken edge. C–E, Interior surfaces of fragments showing stercomare. F, Granellare fragments with attached pieces of stercomare. G, Fragment with partially exposed interior. Scales were not available for D and E.