Reticunassa tringa (Souverbie, 1864)

Figs 2E, 3 D–I, 5; Tables 1–2

Nassa tringa Souverbie in Souverbie & Montrouzier, 1864: 272, pl. 10, fig. 7.

Nassa mamillata Preston, 1907: 267, textfig. 1.

Nassarius (Hima) pauperus [in part] – Cernohorsky 1972: 186, fig. 152 only; 1984: 176, pl. 37, figs 5–6 (syntypes of Nassa tringa), fig. 7 (holotype of N. mamillata).

Type material

NEW CALEDONIA: 6 syntypes of Nassa tringa (MHNBx 2014.TY.89.0, 2 spm; MNHN IM-2000- 28389, 4 spm, http://coldb.mnhn.fr/catalognumber/mnhn/im/2000-28389). We designate MHNBx 2004.TY.89.1 (from the former MHNBx 2004.TY.89.0) as the lectotype (Fig. 3 F–H), length 9.0 mm, width 5.0 mm.

NEW CALEDONIA: holotype of N. mamillata (NHMUK 1923.2.20.8).

Other material examined

NEW CALEDONIA: MONTROUZIER 1993: Touho, stn 1237, 20°46.9′ S, 165°13.8′ E, 0–1 m (15 spm; HD, 2 spm; HK 994.02, 3 spm); Touho, stn 1240, 20°46.5′ S, 165°14.0′ E, 0–2 m (19 spm; HK 994.01, 3 spm; HD 24146, 1 spm); Touho, stn 1241, 20°48.0′ S, 165°15.7′ E, 0–2 m (2 spm; NBC, 1 spm); Touho, stn 1242, 20°46.2′ S, 165°14.5′ E (29 spm); Touho, stn 1244, 20°49.3′ S, 165°15.2′ E (1 spm); Touho, stn 1245, 20°45.2′ S, 165°16.3′ E (3 spm); Touho, stn 1246, 20°42.8′ S, 165°08.7′ E (4 spm); Touho, stn 1253, 20°46.6′ S, 165°14.1′ E, 2–3 m (15 spm); Touho, stn 1259, 20°44.6′ S, 165°13.7′ E, 15–35 m (2 spm); Touho, stn 1261, 20°46′– 20°47′ S, 165°15′– 165°16.5′ E, 45–56 m (2 spm); Koumac, stn 1277, 20°34′ S, 164°16′ E, 0–2 m (4 spm); Koumac, stn 1278, 20°34′ S, 164°16′ E, 0–2 m (2 spm); Koumac, stn 1279, 20°35′ S, 164°15.5′ E (3 spm); Koumac, stn 1282, 20°33.5′ S, 164°13′ E (10 spm); Koumac, stn 1283, 20°33.5′ S, 164°12.2′ E (1 spm); Koumac, stn 1284, 20°33.7′ S, 164°19′ E (19 spm); Koumac, stn 1286, 20°38′– 20°39′ S, 164°16′– 164°17′ E (2 spm); Koumac, stn 1288, 20°40′ S, 164°19′ E (1 spm); Koumac, stn 1289, 20°29.2′ S, 164°10.2′ E (6 spm); Koumac, stn 1290, 20°29.2′ S, 164°10.2′ E (1 spm); Koumac, stn 1291, 20°22.4′ S, 164°06.8′ E (1 spm); Koumac, stn 1292, 20°22.4′ S, 164°06.8′ E (4 spm); Koumac, stn 1298, 20°35.2′ S, 164°16.6′ E, 2–4 m (1 spm). – LAGON: stn 77, Ile Ouen-Baie du Prony, 22°26′ S, 166°32′ E, 22 m (1 spm); stn 384bis, Grand Récif Sud, 22°34′ S, 167°11′ E, 72 m (1 spm); stn 441, Atoll de Huon, 18°04′ S, 162°56′ E, 37 m (1 spm). – New Caledonia, leg. Rossiter, ex coll. Dautzenberg (ZMA.Moll.098635, 5 spm); beach S of Noumea, leg. Mrs Wijsman-Best, 1968 (ZMA Moll. 096210, 2 spm); Ile des Pins (PS, 2 spm); Nouméa, leg. A.P. Greeven-Lels, 1965 (HD 21379, 9 spm).

VANUATU: SANTO 2006: stn AT52, Segond Channel, 15°31.5′ S, 167°12.7′ E, 52–62 m (MNHN IM- 2007-31753, 1 lv, l 9.5 mm, w 4.6 mm, Fig. 3 D–E, I); stn LM23, Segond Channel, 15°31.5′ S, 167°09.6′ E, intertidal (1 spm); stn VM53, Segond Channel, 15°31.0′ S, 167°11.9′ E, intertidal (6 spm); stn VM69, Tutuba I., 15°33.4′ S, 167°16.7′ E, intertidal (MNHN IM-2007-31758, 1 lv); stn FB92, Tutuba I., 15°33.6′ S, 167°16.6′ E, 2–4 m (1 spm); stn VM32, W of Aésé I., 15°26.6′ S, 167°15.2′ E, intertidal (2 spm). – Efate, snorkeling, 2–3 m, leg. T. McCleery, 2002 (HD 17091, 4 spm; HK 994.20, 3 spm).

FIJI: Yasawa I., leg. S.P. Kool (coll. S.P. Kool, 3 spm; HK 994.26, 1 spm).

Description

PROTOCONCH. Whitish, paucispiral, consisting of 1.5–1.75 whorls (Fig. 3I). SEM photograph shows very fine growth lines, and in addition minute pustules on part of last whorl.

SHELL. Elongate-ovate, teleococh with 5–6 whorls, suture impressed. On penultimate whorl 13–17 and on body whorl 12–17 pronounced, round axial ribs, on ventral side of body whorl often decreasing in height towards base.

SPIRAL CORDS. Continuous, moderately broad, rounded primary cords, approximately 4–5 on penultimate and approximately 10–12 on body whorl.

INTERCORDAL SCULPTURE. Fine, evenly-spaced, continuous striae (Fig. 2E), 7–9 on body whorl, sometimes visible between, as well as on spiral cords.

APERTURE. Roundish; outer lip thick, plicate inside, with strong varix; peripheral denticle and more pronounced pleat near siphonal canal. Columella callused, callus sharply bordered, posteriorly slightly extending over body whorl. Columellar lip lirate throughout. Parietal denticle moderately strong.

OPERCULUM. Yellowish, serrated.

SIPHONAL CANAL. Narrow, with strong fasciole. Siphonal area with weak cords and in some specimens faint axial striae between cords.

COLOR. Off white, yellowish to orange or brown. Banding very variable: some specimens with chestnut to dark brown, or nearly black bands; on penultimate whorl a sub- and/or a supra-sutural band; on body whorl occasionally one band directly below periphery and one at base. Occasionally, some or most spiral cords darker, especially between axial ribs. Aperture yellowish, showing outside banding, if present.

ADULT SIZE. 6.7–12.2 mm, usually 8–9.5 mm.

Remarks

Characteristics of this species are a paucispiral protoconch, low spiral cords, in combination with numerous, evenly-spaced intercordal spiral striae (Fig. 2E), axial ribs decreasing in height anteriorly on the ventral side of the body whorl, and the presence of lirae on the columellar callus. In wellpreserved specimens, spiral striae are also visible on top of the spiral cords. The intercordal spiral striae were not mentioned in the original description by Souverbie (in Souverbie & Montrouzier, 1864). However, Preston (1907) mentioned this sculpture in the description of Nassa mamillata . We agree with Cernohorsky (1984), that the latter is a synonym of Reticunassa tringa .

R. tringa can easily be distinguished from R. paupera by its paucispiral protoconch, probably figured by Cernohorsky (1984: 5, fig. 12). Cernohorsky did not discuss protoconch morphology or other conchological features shared by species within the Nassarius pauperus complex, resulting in numerous synonyms of R. paupera, followed by many authors.

R. tringa closely resembles R. visayaensis sp. nov. and R. poppeorum sp. nov. For the differences between R. tringa and these species, see respective Remarks sections.

Habitat

Intertidal to 72 m, more frequently within the first 10 m of depth.

Distribution

New Caledonia, Vanuatu and Fiji (Fig. 5).