Reticunassa intrudens, Galindo & Kool & Dekker, 2017

Galindo, Lee Ann, Kool, Hugo H. & Dekker, Henk, 2017, Review of the Nassarius pauperus (Gould, 1850) complex (Nassariidae): Part 3, reinstatement of the genus Reticunassa, with the description of six new species, European Journal of Taxonomy 275, pp. 1-43 : 34-36

Reticunassa intrudens sp. nov.

urn:lsid:zoobank.org:act:C79E7864-DE80-4A17-94BC-54932F8532CA

Fig. 8 I–L, 11; Table 2

Etymology

The name of this species refers to the spiral cords that seemingly intrude and continue over part of the body whorl of the protoconch.

Type material

Holotype

NEW CALEDONIA: MONTROUZIER 1993, stn 1260, Touho, Banc de Touho , 20°44′ S, 165°14′ E, 49–59 m, Sep. 1993 (MNHN IM-2000-22726 , length 7.9 mm, width 4.3 mm).

Paratypes

NEW CALEDONIA: same collection data as holotype ( MNHN IM-2000-22722, MNHN IM-2000- 28406, MNHN IM-2000-28407, 3 spm; ZMA.Moll.4.09.051, 1 spm; HD 35302, 3 spm; HK 196.01, 4 spm).

Other material examined

NEW CALEDONIA: LAGON: stn 146, Ile Ouen-Baie du Prony, 22°24′ S, 166°55′ E, 40–52 m (1 spm); stn 357, Grand Récif Sud, 22°30′ S, 167°07′ E, 77 m (1 spm); stn 603, Yaté, 22°16′ S, 167°05′ E, 78–80 m (1 spm). – MUSORSTOM 4, stn DW 203, 22°36′ S, 167°05′ E, 105–110 m (1 spm); SMIB 5, stn DW 81, S New Caledonia, 22°38′ S, 167°35′ E, 110 m (5 spm); BATHUS 1, stn DW 678, W coast, 20°49′ S, 165°19′ E, 94–100 m (7 spm). – MONTROUZIER 1993, Touho, stn 1237, Touho Bay, 20°46.9′ S, 165°13.8′ E, 0–1 m (5 spm); Touho, stn 1249, Passe de Touho, 20°49′ S, 165°19′ E, 80–140 m (3 spm); Touho, stn 1250, 20°46.7′ S, 165°13.7′ E, 3–6 m (7 spm); Touho, stn 1251, 20°46.0′– 20°46.5′ S, 165°13.0′ E, 15 m (4 spm); Touho, stn 1253, 20°46.6′ S, 165°14.1′ E, 2–3 m (1 spm); Touho, stn 1257, lagoon in front of Vieux-Touho, 20°44′ S, 165°11′ E, 25–28 m (3 spm); Touho, stn 1260, 20°44′ S, 165°14′ E, 49–59 m (70 spm); Touho, stn 1261, 20°46′– 20°47′ S, 165°15′– 165°16.5′ E, 45–56 m (33 spm); Touho, stn 1268, 20°45.2′ S, 165°08.0′ E, 9–11 m (1 spm); Touho, stn 1275, 20°49′ S, 165°17′ E, 50–62 m (1 spm).

Description

Holotype

PROTOCONCH. Bulbous, flattened, paucispiral, 1.75 whorls, yellowish, axially striate; separation between protoconch and teleoconch indistinct, last half whorl appears to have been “intruded” by the 5 spiral cords on first whorl of teleoconch.

SHELL. Teleoconch consisting of 5 strongly impressed whorls. Penultimate whorl and body whorl with 13 pronounced strong, round axial ribs, varix strong.

SPIRAL CORDS. Penultimate whorl with 7 and body whorl with 10 narrow, fine, equally wide spiral cords.

INTERCORDAL SCULPTURE. Minute spiral striae, occasionally also located on spiral cords.

APERTURE. Outer lip with 5 short and low lirate denticles. Columella wrinkled, columellar callus margined, elevated anteriorly and somewhat curved towards fasciole, posteriorly slightly extending onto body whorl. Parietal denticle prominent, anal canal rather wide.

OPERCULUM. Unknown.

SIPHONAL CANAL. Siphonal area with 1 stronger and 4 weak cords. Fasciole strong.

COLOR. Creamy-yellowish, some spiral cords darker. Whorls with light subsutural band, body whorl with 3 bands, darkest on the thick varix and at base of shell.

ADULT SIZE. 5.4–9.7 mm, usually 7.5–8.5 mm.

Remarks

The most characteristic feature of this species is the broad, flattened, paucispiral and axially striated protoconch with, on the last part of it, 1–5 spiral cords that intrude from the teleoconch ( Fig. 8L ). This character was also mentioned by Cernohorsky (1984) in his description of Nassarius (Hima) pauperus ( Gould, 1850) and was treated as intraspecific variation. These features, the broad, flat paucispiral protoconch and the extremely fine intercordal spiral striae of Reticunassa intrudens sp. nov., make it easy to distinguish it from R. paupera and the other species described in this paper. Moreover, R. intrudens sp. nov. lacks the minute pustules present in some other species described herein and most of the others also have a wider distribution; R. intrudens sp. nov. is only known from New Caledonia. It is one of the smallest species within this group.

Habitat

0–110 m in muddy sand, with the largest concentration of specimens collected at 45– 60 m.

Distribution

Only known from New Caledonia ( Fig. 11 ).

Figures

Fig. 8. Shells of Reticunassa Iredale, 1936. – A–D. Reticunassa annabolteae sp. nov. A–C. Holotype, MNHN IM-2009-12843, length 11.5 mm, width5.3 mm, S Madagascar,Ambatobe, Bavarama,25°27.9′ S, 44°57.6′ E, 0–1 m. D. Protoconch. – E–H. R. goliath sp. nov. E–G. Holotype, MNHN IM-2000- 22724, length 15.5 mm, width 7.9 mm, New Caledonia, Nouméa, leg. D. Massemin, ex coll. H. Kool. H. Protoconch of paratype, MNHN IM-2000-28394. – I–L. R. intrudens sp. nov. Holotype, MNHN IM-2000-22726, length 7.9 mm, width 4.3 mm, New Caledonia, Touho, 20°44′ S, 165°14′ E, 49–59 m. L. Protoconch. – M–P. R. thailandensis sp. nov. M–O. Holotype, ZMA Moll.4.09.047, length 7.35 mm, width 3.8 mm, Thailand, Gulf of Thailand, 6°40.313′ N, 101°43.852′ E, 3–15 m. P. Protoconch. Scale bars: D, H, L, P = 200 µm.

Fig. 11. Geographical and bathymetrical distribution of Reticunassa intrudens sp. nov. Star indicates type locality. Each bar represents all lv or dd specimens.