Granulifusus tatianae, Kantor & Fedosov & Snyder & Bouchet, 2018

Kantor, Yuri I., Fedosov, Alexander E., Snyder, Martin Avery & Bouchet, Philippe, 2018, Pseudolatirus Bellardi, 1884 revisited, with the description of two new genera and five new species (Neogastropoda: Fasciolariidae), European Journal of Taxonomy 433, pp. 1-57 : 32-33

Granulifusus tatianae sp. nov.

urn:lsid:zoobank.org:act:DBF2EAD7-3434-4F1F-A1A1-6ECE73BE5FC3

Figs 4F , 7 E–J

Diagnosis

Shell strong, broadly fusiform, up to 18 mm, protoconch of 3.5 whorls. Teleoconch whorls strongly convex, axial sculpture of broad opisthocline axial ribs, spiral sculpture of strong primary cords and numerous finer secondary cords between them. Aperture lirate inside, columella with several distinct columellar plicae. Teleoconch light tan, axial ribs brown.

Etymology

The specific epithet is named in honour of Tatiana Steyker, wife of Yuri Kantor, patient permanent companion in all travels and many fieldtrips.

Type material

Holotype

NORFOLK RIDGE: south of New Caledonia, 23°17′ S, 168°14′ E, 190–212 m, expedition NORFOLK 1, stn DW1727 ( MNHN IM-2000-33595).

Paratype

NORFOLK RIDGE: 1 specimen, same station as for holotype (MNHN IM-2000-33596); 1 specimen ( ANSP, ex Snyder collection).

Other material examined (all in MNHN)

NEW CALEDONIA: BIOCAL: 1 dd, stn CP84, 20°43′ S, 167°01′ E, 150– 210 m. – SMIB 3: 1 dd, stn DW08, 24°45′ S, 168°08′ E, 233 m. – SMIB 8: 1 dd, stn DW157, 24°46′ S, 168°08′ E, 251–257 m; CHALCAL 2: 3 dd, stn DW84, 23°24′ S, 168°07′ E, 170 m. – NORFOLK 1: 1 lv, 2 dd; stn DW1724, 23°17′ S, 168°14′ E, 200–291 m; 1 lv, 1dd, stn DW1727, 23°17′ S, 168°14′ E, 190– 212 m.

LOYALTY RIDGE: MUSORSTOM 6: 1 dd, stn DW442, 20°54′ S, 167°17′ E, 200 m; 1 lv, 1 dd, stn DW473, 21°09′ S, 167°55′ E, 236 m. – LIFOU 2000: 2 dd, stn DW1650, 20°54.2′ S, 167°01.7′ E, 120– 250 m.

WALLIS AND FUTUNA: MUSORSTOM 7: 1 dd, stn CP517, 14°13′ S, 178°10′ W, 233– 235 m.

Description

Shell fusiform, solid, of 3.5 protoconch and 7 weakly convex teleoconch whorls in holotype. Protoconch bluntly conical ( Fig. 7G ), last ¾ whorl with axial riblets, protoconch/teleoconch discontinuity distinct, marked by appearance of teleoconch sculpture. Protoconch smooth except scattered microgranules, more dense along suture, where they are arranged in oblique lines. Protoconch diameter 820–910 µm (latter in holotype), exposed height 860–920 µm (former in holotype).Teleoconch whorls convex with impressed suture. Axial sculpture of broad, prominent axial ribs, aligned axially on spire from one whorl to the next, 7 ribs per whorl, and of very weak incremental lines. Spiral sculpture of evenly spaced, strong, raised primary cords, in holotype 3 on spire whorls, 13 on last whorl, and numerous, much weaker secondary threads, about 5–7 between two adjacent primary cords. Intersection of secondary spiral threads and incremental lines forming finely reticulate microsculpture. Siphonal canal open, short, recurved. Aperture with 8 strong lirae inside, adapicalmost stronger, forming spirally elongated tooth constricting base of siphonal canal. Inner lip partially detached, with three prominent columellar plicae and one strong parietal tooth, forming well-defined posterior canal. No umbilicus. Colour of protoconch and interior of aperture white. Teleoconch background colour creamy white, axial ribs light brown, spiral cords lighter than ribs.

Holotype measurements: SL 14.3 mm, AL (without canal) 4.5 mm, SW 6.1 mm.

Radula (MUSORSTOM 6, stn DW473, 21°09′ S, 167°55′ E, 236 m, Fig. 4F ) narrow, distance between outer edges of lateral teeth about 55 µm, with slender central tooth, about twice as long as broad, bearing three strong cusps. Lateral tooth medium broad, with long basal ‘handle’ on outer edge, with five strong, subequal cusps, the outermost more clearly separated from the rest, and one smaller inner cusp. Narrow but distinct transverse folds of the membrane situated serially between rows of lateral teeth.

Distribution

Southwest Pacific, known only from Futuna and the New Caledonia region, alive in 200–236 m, empty shells in 170– 251 m.

Remarks

Granulifusus tatianae sp. nov. is superficially similar to Okutanius kuroseanus gen. et comb. nov. Both species have brown axial ribs aligned along the spire against a lighter, creamy background, and both have a multispiral protoconch indicating planktotrophic larval development. Okutanius kuroseanus gen. et comb. nov., however, reaches a much larger adult size and is proportionally broader at comparable size; it has a longer siphonal canal, weaker columellar plicae, and spiral cords of uneven strength, without the very regular pattern of evenly spaced primary cords separated by 5–7 very fine, even, spiral threads of G. tatianae sp. nov.

The species also resembles G. norfolkensis sp. nov. in sculpture and particularly in apertural armature. Nevertheless, the shell shape in Granulifusus tatianae sp. nov. is rather different, and the species can be easily distinguished by size at maturity: G. tatianae sp. nov. attains a significantly larger size, up to 18.1 mm, versus 13.6 mm in G. norfolkensis sp. nov.

The new species was not examined molecularly and we tentatively assign it to Granulifusus based on the similarities of shell sculpture and apertural ornamentation to G. norfolkensis sp. nov. and G. williami comb. nov.

Figures

Fig. 4. Radulae of species of Granulifusus and Okutanius gen. nov.A. Granulifusus discrepans (Kuroda & Habe, 1961), shell, see Fig. 3D (MNHN IM-2013-46327). B. Granulifusus williami (Poppe & Tagaro, 2006), comb. nov., shell, see Fig. 3H (MNHN IM-2013-58726). C–D. Granulifusus jeanpierrevezzaroi (Cossignani, 2017) comb. nov., shell, see Fig. 5B–D, arrow points to regularly spaced folds of the radular membrane (MNHN IM-2007-34593). E. Granulifusus annae sp. nov., New Caledonia, BATHUS 1, stn CP669, 20°57′ S, 165°35′ E, 255–280 m, shell, see Fig. 6F. F. Granulifusus tatianae sp. nov., Loyalty Ridge, MUSORSTOM 6, stn DW473, 21°09′ S, 167°55′ E, 236 m. G. Okutanius kuroseanus (Okutani, 1975) gen. et comb. nov., New Ireland, shell, see Fig. 9A (MNHN IM-2013-59070). H. Okutanius ellenae gen. et sp. nov., New Caledonia, NORFOLK 1, stn DW1658, 23°26′ S, 167°50′ E, 320–336 m, shell, see Fig. 10H).

Fig. 7. A–D. Granulifusus norfolkensis sp. nov. A–C. Holotype, SL 13.0 mm, sequenced (MNHN IM-2013-68811). D. New Caledonia, Norfolk Ridge, 23°23′ S, 168°00′ E, 430–480 m, sequenced specimen (MNHN IM-2007-36921). E–J. Granulifusus tatianae sp. nov. E–G. Holotype (MNHN IM- 2000-33595). H. Paratype, SL 15.0 mm (MNHN IM-2000-33596). I. New Caledonia, SMIB 3, stn DW8, 24°45′ S, 168°08′ E, 233 m, SL 18.1mm. J. New Caledonia, CHALCAL 2, stn DW84, 23°24′ S, 168°07′ E, 170 m, SL 17.7 mm. All shells to the same scale.