Triphoris (Ino) corrugatus Hinds, 1843

Albano, Paolo G., Bakker, Piet A. J. & Sabelli, Bruno, 2019, Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Natural History Museum of the United Kingdom, London, Zoosystematics and Evolution 95 (1), pp. 161-308 : 161

Triphoris (Ino) corrugatus Hinds, 1843

Figure 27

Triphoris (Ino) corrugatus Hinds 1843b: 18, not illustrated. Illustration available in Hinds (1844): 29, pl. 8, fig. 7.

Type locality.

New Guinea and Straits of Malacca.

Type material.

Syntypes: NHMUK 1879.2.26.195: 3 specimens, New Guinea and Straits of Malacca (J. Lombe Taylor coll.) ; NHMUK 1998167/1-5: 5 specimens, Straits of Malacca (coll. E. Belcher) .

Original description.

Testa cornea; anfractibus 17-20 bicarinatis, inter carinas corrugatis, medio carina secondaria; sutura leviter carinata; apertura rotunda; sinu laterali lineari. Axis 6½ lin.

Geog. New Guinea; dredged from 23 fathoms, among fine gravel. Straits of Malacca; from 18 to 23 fathoms.

Translation of the Latin text.

Brown shell; 17-20 bicarinated whorls with corrugated interspaces, smaller median carina; slightly carinated suture; round aperture; linear posterior sinus. Height 6½ lines.

Diagnosis.

Adult specimens of the type series range between 11.2 and 14.2 mm. Shell conical and very elongated. The teleoconch has 17 flat sides with three strong smooth spiral cords. The second whorl develops later along the teleoconch and is initially weakly undulated as a result of the intersection with prosocline axial riblets which are well developed in the lectotype. A fourth smooth spiral cord is visible on the last whorls. An additional spiral cord develops between the second and the third and is clearly visible on the peristome. The base has two additional smooth spiral cords. Syntype NHMUK 1879.2.26.195/2 (but see Remarks and Fig. 27A-D ) bears a multispiral brown protoconch; the first whorl and half are smooth with numerous rounded tubercles. Three whorls follow with strong axial riblets intersecting one spiral keel in the first and two spiral keels in the following whorls. The original description suggested the species to be brown, but some specimens show darker fletches.

Remarks.

Specimens belonging to these lots show variable strength of the prosocline axial ribs between the main cords. Hinds highlighted in the original description the presence of strong axial ribs and likely named the species after it. The significance of this character for species delimitation has still to be understood. Moreover, two colour forms are present in the type series: syntype NHMUK 1879.2.26.195/2 (Fig. 27A-D, H, I ) shows a colouration of light spiral cords on a brown background, whereas the syntype NHMUK 1879.2.26.195/1 (Fig. 27F-G ) is brown with darker flammulae. Therefore, this syntype may belong to a different species of this complex group.

This name has been used for the first Indo-Pacific triphorid species detected in the Mediterranean Sea, likely introduced through the Suez Canal. Notwithstanding the complexity of the group, the introduced species in the Mediterranean Sea probably best matches Viriola bayani Jousseaume, 1884 ( Steger et al. 2018).

Figures

Figure 27. Triphoris corrugatus Hinds, 1843. A-D, H, I Syntype NHMUK 1879.2.26.195 / 2, New Guinea and Straits of Malacca (J. Lombe-Taylor coll.): front (A, B), side (C), back (D), protoconch (H, I). E, J Syntype NHMUK 1879.2.26.195 / 3, New Guinea and Straits of Malacca (J. Lombe-Taylor coll.): front (E), protoconch (J). F, G, L-N Syntype NHMUK 1879.2.26.195 / 1: front (F), side (G), peristome (L, M), microsculpture (N), K Figure in Hinds 1844. O Original labels lot NHMUK 1879.2.26.195. Scale bars: A-G: 1 mm; H, I: 0.2 mm; J: 0.05 mm; L-N: 0.5 mm