Terebellum delicatum Kuroda & Kawamoto, 1956

Maxwell, Stephen J., Rymer, Tasmin L. & Congdon, Bradley C., 2021, Resolving phylogenetic and classical nomenclature: A revision of Seraphsidae Jung, 1974 (Gastropoda: Neostromboidae), Zootaxa 4990 (3), pp. 401-453 : 436

Terebellum delicatum Kuroda & Kawamoto in Kawamoto & Tanabe, 1956

Figure 9A

1956 Terebellum terebellum delicatum Kuroda & Kawamoto in Kawamoto & Tanabe, p. 87, pl. 10, fig. 91. Maxwell et al. 2018b, p. 64. = Terebellum t. delicatum Kuroda & Kawamoto — Kira 1959, p. 34. = Terebellum terebellum delicatum Kuroda & Kawamoto — Habe 1961, p. 58, pl. 17, fig. 1. = Terebellum t. delicatum Kuroda & Kawamoto — Kira 1962, p. 34. = Terebellum terebellum delicatum Kuroda & Kawamoto — Habe 1964, p. 58, pl. 17, fig. 1. Kreipl & Poppe 1999, p. 10, pl. 8, fig. 5. = Terebellum terebellum forma delicatum Kuroda & Kawamoto, 1961 — Jung & Abbott 1967, p. 449, pl. 321, figs. 9, 10. = Terebellum delicatum Kuroda & Kawamoto, 1961 — Liverani 2014, p. 15, pl. 132, figs. 1–4. = Terebellum delicatum Kuroda & Kawamoto, 1961 — Poppe & Tagaro 2016, p. 93, pl. 8, fig. 6. = Terebellum delicatum Kuroda & Kawamoto in Kawamoto & Tanabe, 1956. Maxwell et al. 2018b, p. 64, figs. 1i–k & 2a–d.

Type material. Lectotype —Hagi HH-Mo000214 ( Maxwell et al. 2018b). The type measures 29.0 mm in length, with a width of 6.5 mm ( Maxwell et al. 2018b).

Type locality. Kurae , Hagi, Japan [Recent] .

Diagnosis. The shell is smooth, ovately rotund and quadrate at the base. The sutures are well-developed, and the labrum is protocyrt. The spire is blunt, and the aperture extends for three-quarters the length of the shell. There is a distinctive central axial mid-columella ridge that may not be evident in subadults. The species lacks the anterior lip marginal black line at maturity. The shell background colour is usually tan with circular white spotting, with a single dark smaller spot within each larger white one such that their circumferences touch, resulting in a white crescent shape partially surrounding the darker spot ( Maxwell et al. 2018b).

Distribution. Specimens of T. delicatum have been found in southwest Japan, Vietnam, Philippines, and recently in Queensland, Australia ( Maxwell et al. 2018b). While first-hand collecting records from material examined indicates that the species has been found periodically intertidally in Queensland, this contrasts with reports of a more restricted range to deeper waters in the Philippines ( Poppe & Tagaro 2016; Maxwell et al. 2018b). Records from Mozambique ( Maxwell et al. 2018b) need to be confirmed, as they are located well outside the Western Pacific rim where the species is known to occur. New Records: Japan. Kurae, Hagi (Hagi City Museum). Vietnam Nha Trang area, 24.0–37.0 mm ( Maxwell et al. 2018b). Australia Bowen Sand Flats, 29.5 mm ( Maxwell et al. 2018b); Buchans Point, 19.0–27.0 mm ( Maxwell et al. 2018b); Dingo Beach, Queensland ( Maxwell et al. 2018b); Saunders Beach ( Maxwell et al. 2018b); Torres Straits ( Maxwell et al. 2018b); Wonga Beach ( Maxwell et al. 2018b). Mozambique Nacala Bay, 32.0–37.0 mm ( Maxwell et al. 2018b).

Remarks. The shell of T. delicatum differs from other members of Terebellum by having a central mid-columella ridge, a character that is lacking in all other members of the complex, which typically have the columella ridge commencing at the posterior suture of the labrum and the body whorl. Furthermore, the new species lacks the marginal black line on the anterior edge of the lip typical in other Terebellum at maturity.

Figures

FIGURE 9. Terebellum Röding, 1798. A. Terebellum delicatum Kuroda & Kawamoto in Kawamoto & Tanabe, 1956, Khánh Hòa, Nha Trang, Vietnam, length 27 mm (NMR 54693). B. Terebellum hubrechti Poppe & Tagaro, 2016, Caubian Deep, Bohol, Philippine, length 33.2 mm (image Conchology Inc.). C. Terebellum simoni Dekkers et al., 2019, Bohol Island, Philippines, length 50.6 mm (Paratype 1, AMD STR2269). D. Terebellum terebellum. D1. Vanuatu, length 63.4 mm (Coll. Guido and Philippe Poppe, 464722). D2. Solomon Islands, size unknown (NMR 44172). D3. Solomon Islands, size unknown (NMR 54964). D4. Leyte, Philippines, length 41.3 mm (Coll. Guido and Philippe Poppe, 378696).