Nodularia guiensis Hou & Wu, 2025

Nodularia guiensis Hou & Wu sp. nov.

Fig. 2 View Figure 2

Type material.

Holotype: • SXNU_24090707 (length 46.57 mm, height 21.34 mm, width 15.68 mm) (Fig. 1 D View Figure 1 ) ; Paratypes: • SXNU_24090705 ; SXNU_24090706 ; SXNU_24090708 (Fig. 1 A – C View Figure 1 ) .

Etymology.

We collected this species in Guangxi Province, so we named it ‘ Gui’ after the abbreviation of Guangxi Province and then Latinized it. We recommend using ‘ Gui Jiejie Bang’ (桂结节蚌) as the common name.

Diagnosis.

Shell medium-sized, moderately thick, overall slender shape; anterior margin obviously indented with shell umbo resulting in lower dorsal margin. The shell morphology of this newly discovered species is highly similar to Nodularia huana . But the new species can be easily distinguished from other congeneric species using the COI barcode (Fig. 3 View Figure 3 ). It has a genetic distance (uncorrected p - distance) of 7.7 % from Nodularia huana , while its genetic distance from Nodularia fusiformans is the smallest at 5.5 % (Table 1 View Table 1 ).

Description.

Shell medium-sized, moderately thick, overall slender shape; dorsal margin curved; anterior margin round; ventral margin nearly straight; posterior margin slightly blunt, located at almost 1 / 2 of shell height; umbo located at 1 / 4 of shell length and slightly higher than the dorsal margin; umbo sculptured with rough nodes or W -shape ridges; epidermis yellow-brown and young epidermis light brown with a little green, shell surface covered with fine to rough concentric ridges; ligament short, narrow, and brown; anterior adductor muscle attachment elliptical; posterior adductor muscle attachment round or oval and smooth; mantle muscle attachment obvious; left valve with two pseudocardinal teeth, lamellae, anterior tooth wide and flat, posterior tooth slightly thick and pyramidal, anterior pseudocardinal tooth of some individuals split into two pieces, and having two lateral teeth; right valve with one thick pseudocardinal tooth and one lateral tooth; lateral teeth of both valves long and compressed; nacre silvery-white to bluish-white, and shiny (Fig. 2 View Figure 2 ).

Anatomical characteristics.

The papillae of the incurrent aperture conical, arranged in two to three rows; weakly developed papillae of the excurrent aperture arranged in one row, and knobs or raised bumps dense; the pigmentation of the incurrent and excurrent aperture absent; labial palps medium-thick (Fig. 2 View Figure 2 ).

Distribution.

Sanli Town, Shanglin County, Nanning City, Guangxi Province.