Semisulcospira egretta Y.-Z. Meng 2025, sp. nov.
Creators: name: Xu, Yi-Bin
name: Meng, Yuan-Zheng
name: Zeng, Sheng
name: Wang, Hang-Jun
name: Zhong, Shen
name: Yang, De-Yuan
name: Zhou, Xi-Ping
name: Glasby, Christopher J.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Cerithiida
Semisulcospiridae
Semisulcospira
Semisulcospira egretta

description: Semisulcospira egretta Y.-Z. Meng sp. nov.
Table 2, Figs 1, 6, 7, 8
Material examined.
Holotype. China • Haicang District [海沧区], Xiamen City [厦门市], Fujian Province [福建省], China; 24°36'29"N, 117°53'39"E; 13 January 2024; Yuan-Zheng Meng leg.; MBSM -2024-XM-001.
Paratypes. China • 20; the same data as holotype; MBSM -2024-XM-002 to 004, XMU_DYY_TZS_001 to 002 and 005 to 017, YZM / 1 (empty shell) • 16; the same locality as the holotype; 16 April 2022; Yuan-Zheng Meng and Li-Wen Lin leg.; XMU_DYY_XMA 01 to A 15, LWL / 1 (empty shell).
Other material.
China • 13; Tong’an District [同安区], Xiamen City [厦门市], Fujian Province [福建省], China; 24°52'35"N, 118°03'01"E; 26 February 2023; Yuan-Zheng Meng and Li-Wen Lin leg.; XMU_DYY_XMB 01 to B 04, XMU_DYY_XMC 01 to C 06; XMU_DYY_RTM 05 and RTM 25, YZM / 1 (empty shell) • 3; the same locality as holotype; 16 April 2022; Yuan-Zheng Meng and Li-Wen Lin leg.; XMU_DYY_RTM 05, XMU_DYY_RTM 02, 04 to 05.
Diagnosis.
Viviparous. Shell medium size, up to 25 mm, yellow-brownish, elongate, smooth, thin, comprising seven to nine whorls. Pregnant female bears about 150 embryos. Embryonic shell about 0.5 mm in length. Only known in Xiamen, Fujian Province, China.
Description.
Shell (Fig. 6 A – F, Table 2, n = 45). Shell height 10.7–24.1 mm, width 5.7–11.7 mm, body whorl height 7.1–16.6 mm, aperture width 3.2–6.2 mm, aperture height 4.8–12.2 mm. Shell elongate, conical, thin, brown to yellowish-brown, sometimes with 1–3 brown bands and black sediment, five to seven whorls. Shell surface smooth, without any spiral ridges or ribs. Apex always eroded. Aperture ovate. Measurements and counts are shown in Table 1.
External morphology (Fig. 1, n = 20). Snout, neck, sides of foot black in color with golden spots on tentacles. Snout broad, squarish, with long cephalic tentacles, tentacles significantly longer than snout in length. Viviparous. Mantle edge smooth.
Operculum (Fig. 6 A, n = 17). Corneous, ovate, brown, with approximately 3 whorls. Nucleus of operculum in lower one third of the operculum.
Radula (Fig. 7 A, B, n = 9). Central teeth with one large central triangular cusp, and three to four conical denticles on each side, lateral teeth with single prominent triangular cusp, with two to three small denticles on each side, inner marginal teeth with four to five and outer with five to seven flattened, rounded denticles.
Midgut (Fig. 8 A, n = 4). Oesophagus opening under ledge on the left side of midgut floor. Marginal fold extending anteriorly from oesophageal aperture alongside major typhlosole, then turning posteriorly bordering right margin of sorting area. Sorting area triangular, posterior tip curving left around sorting area pad. Midgut roof left of sorting area coarsely folded and cuticularised. Gastric shield tongue-shaped and concave. Glandular pad small, triangular, overhanging lip forming shallow pocket behind gastric shield and curving right. Crescentic ridge long, shallow, deep crescentic groove. Caecal fold along midgut floor opposite caecum. Style sac U-shaped, in contact with intestinal groove.
Reproductive systems.
Female (Fig. 8 B, n = 20). Long narrow oviduct, emerging from ovary, entering near seminal receptacle without protrusion. Ventral edge of spermatophore bursa with groove with curved surface forming sperm gutter, extending toward mantle cavity. Brood pouch uterine, on dorsal side of spermatophore bursa, inflated dorsally, separated into many cells, filled with eggs or embryos, depending on level of sexual development.
Male. No male was observed.
Sex ratio. All 20 dissected individuals were female.
Embryonic shell (Fig. 7 C, D, n = 150). Globose, smooth, possessing slight spiral striae, usually comprising about 1.5 whorls. About 0.5 mm in height.
Habitat and distribution
(Fig. 1). The species was collected in mountain streams of Haicang District and Tong’an District of Xiamen, Fujian Province.
Etymology.
The word egretta means “ egret ” in Latin. Egret is the city bird of Xiamen, which also suggests the type locality of this species. We suggest the Chinese common name as “ 白鹭短沟蜷 ”.
Comparative remarks.
Many species of Semisulcospira have sculptured shells, for example, S. ningpoensis (I. Lea, 1857), S. gredleri (O. Boettger, 1886), and S. reticulata Kajiyama & T. Habe, 1961, etc. But Semisulcospira egretta sp. nov. can be easily distinguished from them by its thin and smooth shell. This species is also characterized by the relatively small embryonic shells (about 0.5 mm in length), and the denticle numbers on the inner and outer marginal teeth of its radula (four to five on the inner and five to seven on the outer). For detailed comparisons with similar species (also with relatively smooth shells refer) to Table 3. Semisulcospira egretta sp. nov. is the only semisulcospirid species documented in Xiamen; the only region from which it is currently known.
description: Published as part of Xu, Yi-Bin, Meng, Yuan-Zheng, Zeng, Sheng, Wang, Hang-Jun, Zhong, Shen, Yang, De-Yuan, Zhou, Xi-Ping & Glasby, Christopher J., 2025, A new species of Semisulcospira O. Boettger, 1886 (Gastropoda, Cerithoidea, Semisulcospiridae) from Fujian, China with mitochondrial genome and its phylogenetic implications, pp. 17-34 in Zoosystematics and Evolution 101 (1) on pages 17-34, DOI: 10.3897/zse.101.136882