Cuneopsis celtiosimilis Hou & Wu, 2025

Cuneopsis celtiosimilis Hou & Wu sp. nov.

Fig. 1 a View Figure 1 ; Suppl. material 2: fig. S 1

Type material.

Holotype (Fig. 1 a View Figure 1 ) • SXNU_24100210 (length 119.1 mm, height 45.19 mm, width 32.74 mm); Luoshan County, Xinyang City , Henan Province, China . Paratypes (Suppl. material 2: fig. S 1 a, c, d) • three specimens, SXNU_24082201 , SXNU_24100211 , and SXNU_24100212 . Same collection location as the holotype .

Morphological diagnosis.

Shell long, wedge-shaped; the umbo situated at 1 / 6 of the shell length; the epidermis black-red; nacre blue-white; and the two pseudocardinal teeth on the left valve join together and form in a continuous strip (Fig. 1 View Figure 1 ); right valve has one low, squashed, and irregular pseudocardinal tooth. The labial palps long elliptical (Fig. 2 a 1 View Figure 2 ); the papillae of the incurrent aperture short, pyramidal shape, and arranged in two rows (Fig. 2 a 2 View Figure 2 ); and the papillae at the edge of the excurrent aperture not prominent and tightly arranged in a row (Fig. 2 a 3 View Figure 2 ).

Molecular diagnosis.

The phylogenetic tree indicates that the new species forms a distinct lineage, and it is closely related to Cuneopsis kiangsiensis (Fig. 3 View Figure 3 ). The genetic distance between the new species and its congeneric species shows that the smallest distance is observed with Cuneopsis kiangsiensis (4.6 %) (Table 2 View Table 2 ).

Description.

Shell thick, strong, both valves unequal. Shell long, wedge-shaped, slightly thickened, slightly inflated; anterior margin convex prominently; ventral margin arc-shaped; umbo located at 1 / 6 of the shell length; periostracum black-red; shell surface sculptured with fine concentric growth lines (Fig. 1 View Figure 1 ; Table 1 View Table 1 ). Anterior adductor muscle attachment deep and rough; posterior adductor muscle attachment shallow and smooth; nacre blue-white; mantle muscle attachment obvious. Hinge well developed; left valve has two pseudocardinal teeth; anterior tooth small, and posterior tooth thick, both pseudocardinal teeth connect together and arranged in continuous strip; right valve has only one low, squashed, and irregular pseudocardinal tooth; left valve has two lateral teeth, and both arranged in a paralleled straight line; right valve has one lateral tooth (Fig. 1 View Figure 1 ; Table 1 View Table 1 ). Papillae in the incurrent aperture short, pyramidal shape, arranged in two rows; papillae in the excurrent aperture weakly developed, tightly arranged in one row; and the pigmentation of the incurrent and excurrent aperture significant; labial palps medium-thick, long elliptical (Fig. 2 View Figure 2 ; Table 1 View Table 1 ).

Etymology.

This newly discovered species exhibits morphological similarities with Cuneopsis celtiformis , which led us to incorporate this resemblance into its naming. Specifically, we used the word ‘ celti’ (derived from ‘ celtiformis ’) with the middle ‘ o’ connected to the Latinized word ‘ similis’ (similar) to name this new species. For the common name, we recommend “ Similar Wedged Mussel ” (English) and “ Jin Si Xie Bang ” (近似楔蚌) (Chinese).

Distribution.

Shi River, a tributary of Huai River, Luoshan County, Xinyang City, Henan Province, China.