Pseudobornella qingdaoensis, Zhang & Wang, 2025

Zhang, Shuqian & Wang, Juhao, 2025, Description of a new species of Pseudobornella Baba, 1932 (Gastropoda, Nudibranchia, Dendronotidae) from the Yellow Sea, ZooKeys 1241, pp. 301-314 : 301-314

Pseudobornella qingdaoensis sp. nov.

Figs 1 , 2 , 3

Type material.

Holotype (Fig. 1 A, B ): China • 1 specimen, length alive 40 mm; dissected; Shandong Province, Qingdao, Golden Beach Park , intertidal zone; 35 ° 57 ' 03 " N, 120 ° 14 ' 26 " W; 18 Jan. 2025; Shu-Qian Zhang leg.; MBM 288155 . Paratypes 1–4: China • 4 specimens, lengths 35–40 mm; complete; complete; Shandong Province, Qingdao, Golden Beach Park , intertidal zone; 35 ° 57 ' 03 " N, 120 ° 14 ' 26 " W; 20 Jan. 2025; Shu-Qian Zhang leg.; MBM 288156 – MBM 288159 . Paratype 5 (Fig. 1 C ): China • 1 specimen, preserved length 10 mm; dissected; Shandong Province, Qingdao, Taiping Bay , intertidal zone; 11 Apr. 2024; Ju-Hao Wang leg.; MBM 288160 . Paratype 6 (Fig. 1 D ): China • 1 specimen, preserved lengths 20 mm; dissected; Shandong Province, Rushan , intertidal zone; 19 Apr. 2019; Ju-Hao Wang leg.; MBM 288161 . Paratypes 7–10: China • 4 specimens, preserved lengths 20 mm; complete; same collection data as paratypes 6; MBM 288162 – MBM 288165 .

Diagnosis.

A large Pseudobornella reaching 40 mm in body length. Background color generally translucent yellow to dark brown, with numerous scattered orange to brown spots and white blotches. Radula formula 11 × 3.0. 3.

Description.

External morphology (Fig. 1 ). Living animals up to 40 mm in length. Foot wide and tapering relatively abruptly towards the tail. Background color generally translucent yellow to dark brown, with numerous scattered orange to brown spots and white blotches. In some individuals, the white blotches forming two longitudinal streaks running along both sides of the dorsum. Anterior margin of head rounded. Each side of the mouth equipped with four or five smooth, tapering oral tentacles of varying size. Rhinophore sheath very elongate. Upper edge of each rhinophore sheath bearing four lateral digitiform branched papillae and one posterior papilla that is remarkably longer. Rhinophores with ~ 12 lamellae. Dorsal margin with four pairs of dorsolateral papillae, decreasing in size towards the posterior end of the foot. Each papilla with numerous unbranched gills attached to its inner side. Anus small, located on the right side of the dorsum between the first and second pair of dorsolateral appendages. Genital opening located on the right side, midway between the rhinophore sheath and the first dorsolateral appendage. Foot pale pink, scattered with numerous very small, indistinct darker spots, separated from the head by a long, transversal groove.

Internal anatomy. Jaws (Fig. 2 A, B ) elongate, inner margin (masticatory margin) terminating distally in a small, pointed process. Masticatory margin equipped with rows of short, cone-shaped rodlets. Radular (Fig. 2 C – F ) formula 11 × 3.0. 3. Rachidian teeth stout, with a strong and bluntly pointed cusp and ~ 9–12 denticles on both sides of the cusp. Innermost lateral teeth with a very strong elongate and sharp cusp and serrated sides. Outer lateral teeth simple and hamate, and outermost one smallest.

Reproductive system (Fig. 3 ) located in the front right corner of the body. Ampulla very large, sausage-shaped, one end connecting with ovotestis via a thin hermaphroditic duct, the other end divided into two different, thin ducts: the short oviduct entering the female gland mass and the second duct branching into a wide, short prostate which extends into a long, folded vas deferens, narrowly opening to a wide and stout penial sac. Two ducts departing from the genital aperture: vagina relatively long and simply folded, connecting with a small, rounded receptaculum seminis; second duct wider and shorter, connecting with a very large pyriform bursa copulatrix.

Etymology.

The new species is named after its type locality, Qingdao.

Distribution and habitat.

Known from Yellow Sea, China, and possibly also distributed in Japan ( Kinoshita 2002; Nobuhiko 2017). It was found in the rocky intertidal zone, feeding on a hydroid ( Kinoshita 2002).

Figures

Figure 1. Pseudobornella qingdaoensis sp. nov. A, B holotype, MBM 288155, length 40 mm C paratype 5, MBM 288160, preserved length 1.0 cm D paratype 6, MBM 288161, preserved length 20 mm.

Figure 2. Jaws, radulae of Pseudobornella qingdaoensis sp. nov. A jaw, MBM 288155 B jaw masticatory border, MBM 288155 C, D radula, MBM 288155 E, F radula, MBM 288161. Scale bars: 1 mm (A); 50 μm (B, C); 20 μm (D, F); 100 μm (E).

Figure 3. Reproductive system of Pseudobornella qingdaoensis sp. nov., with ovotestis and female gland mass removed, MBM 288155. Abbreviations: am – ampulla; bc – bursa copulatrix; ga – genital aperture; hd – hermaphrodite duct; ov – oviduct, pr – prostate, ps – penial sac; rs – receptaculum seminalis; va – vagina; vd – vas deferens. Scale bar: 1 mm.