Coluzea altocanalis Dell, 1956

Harasewych, M. G., 2011, The Living Columbariinae (Gastropoda: Neogastropoda: Turbinellidae) of New Zealand, Zootaxa 2744 (1), pp. 1-33 : 18-20

Coluzea altocanalis Dell, 1956

( Figures 37 , 41 , 62–76 )

Synonymy:

Coluzea altocanalis Dell, 1956: 50 , figs. 53, 54.

Columbarium (Coluzea) altocanalis Powell, 1979: 169 .

? Fulgurofusus sp. cf. benthocallis Darragh, 1969: 104, pl. 6, fig. 114.

Diagnosis. Very large species with narrow, fusiform, white shell with tall, conical spire (spire angle 30–36˚), laterally oriented, flange-like keel along shell periphery, long (~½ shell length) axial siphonal canal. Protoconch cylindrical, of ~2¼ whorls. Teleoconch with two strong, posteriorly deflected cords between suture and periphery. Axial sculpture limited to growth lines, irregular undulations in spiral sculpture.

Description. Shell ( Figures 62–70 ) largest in subfamily (to 127.3 mm), moderately thin, with very tall, conical spire (spire angle 30–36˚), small aperture, long, axial siphonal canal. Protoconch ( Figures 73–74 ) tall, narrow, nearly cylindrical, with weakly inflated, heavily eroded whorls increasing in diameter from 520 µm to 1.7 mm in ~2¼ whorls. First whorl deflected from coiling axis of shell by ~58˚. Transition to teleoconch marked by development of strong shoulder followed within ¼ whorl by onset of spiral cords and laterally directed peripheral keel. Teleoconch extrapolated to consist of up to 8 strongly convex, broadly ovate whorls. Suture ( Figure 68 , s) abutted to or subducted beneath keel of anterior carina ( Figure 68 , ac) of previous whorl. Sculpture limited to two prominent spiral cords between suture and periphery, a strong, flange-like peripheral keel ( Figure 68 , pk), a prominent cord between keel and anterior carina, 2–4 weaker cords between carina and siphonal canal, and 6–12 weak cords along proximal ⅓ of siphonal canal. Spiral cords between suture and shoulder pronounced, developing into posteriorly deflected minor keels ( Figure 68 , dk) with increasing shell size. Fine to very fine spiral threads on keels and between major cords. Axial sculpture lacking, apart from weak growth striae and occasional undulations along spiral sculptural elements. Aperture ovate, tapered anteriorly, narrower in juveniles, more rounded with increasing shell size ( Figures 70 →66→62), deflected from shell axis by 14–24˚. Outer lip glazed, furrowed beneath spiral cords and keels, most deeply beneath peripheral keel. Inner lip smooth. Outer shell layer comprising surface sculpture resorbed along parietal region, columella and proximal siphonal canal prior to deposition of a thin porcellaneous glaze. Siphonal canal long (~½ shell length), narrow, axial, stout, proximal ½ straight, distal ½ weakly spiral. Shell color uniformly white. Periostracum very thin, yellowish, finely lamellose. Operculum ( Figures 71, 72 ) thin, elongated, broadly rounded posteriorly, sharply tapering anteriorly, attached to columellar muscle along broadly ovate area limited to posterior ⅔ of operculum. Operculum weakly corrugated, with thickened lateral edges. Nucleus anterior, free edges are usually worn, abraded.

Dried tissues of single juvenile specimen ( Figure 70 , SL = 13.2 mm) rehydrated. General anatomical organization typical of Coluzea . Radular ribbon ( Figures 75, 76 ) short, of ~42 rows of teeth. Rachidian teeth 25.7 µm wide, basal plate with U-shaped central section flanked by broad, rectangular, laterally expanded edges. Three long, cylindrical cusps, central cusp longest (12.5 µm), confined to central 9.5 µm of rachidian tooth. Lateral teeth, each with a single, long (20.7µm), scythe-shaped cusp, attached to radular ribbon along a basal plate 14 µm wide.

Type locality. ( Figure 37 ,) Chatham Rise [43°40.0’S, 179°28.0’E], 403 m. 24 Jan. 1954, MV ALERT.

Type material. Holotype NMNZ M.008219, paratype 1, NMNZ M.008220, both from the type locality. A second paratype was deposited at the Canterbury Museum ( Dell, 1956: 50).

Material examined. NORTH ISLAND: 2 NMNZ M.074636, E of Cape Kidnappers [39°52.8’S, 177°36.5’E], 785–882 m, mud, 21 Jan. 1981, RV TANGAROA. CHATHAM RISE: 1 NMNZ M.059580, Northern Mernoo slope [42°38.1’S, 176°16.3’E], 980–1,000 m, mud, 11 Jan. 1979, RV TANGAROA; 6 NMNZ M.059715, Northern Mernoo slope [42°38.2’S, 176°10.5’E], 999– 984 m, mud, 11 Jan. 1979, RV TANGAROA. SOUTH ISLAND: 1 NMNZ M.058503, Papanui Canyon , NE of Taiaroa Heads [45°46’S, 171°03’E], 660 m, 1 Sep. 1976, RV MUNIDA .

Additional material at NMNZ. NORTH ISLAND: 1 NMNZ M.100332, SE of Mahia Peninsula [39°32.8’S, 178°16.5’E], 857–880 m, 29 Sep. 1989, RV JAMES COOK. CHATHAM RISE: 1 NMNZ M.059755, northern slope of Mernoo Bank [42°57.9’S, 175°27.8’E], 500–518 m, mud, 12 Jan. 1979, RV TANGAROA. SOUTH ISLAND: 1 NMNZ M.059621, ridge c 35 km off Clarence River mouth [42°16.3’S, 174°20.8’E], 790–860 m, 14 Jan. 1979, RV TAN- GAROA; 1 NMNZ M.050976, off Kaikoura Peninsula [42°28.5’S, 173°47.5’E], 786 m, mud, 18 Mar. 1976, RV ACHERON .

Distribution ( Figures 37 , 41 ). Coluzea altocanalis inhabits the upper continental slope off the eastern coast of North Island, South Island, and along the Chatham Rise at depths ranging from 403–1,000 m. This species has a confirmed bathymetric range of 403–984 m, and a mean station depth [n = 9] of 675.6 m. There appears to be an inverse relationship between the depth at which this species occurs and latitude, with southern records occurring at shallower depths than northern records.

Remarks. Coluzea altocanalis is easily distinguished from the other living New Zealand species of Columbariinae on the basis of its large size, narrow spire angle, lack of axial sculpture, even on the early whorls, cylindrical protoconch, and prominent, keel-like spiral sculpture. Young specimens resemble Coluzea kiosk Finlay, 1930 , a fossil species from the Hutchinsonian Stage (Burdigalian – Aquitanian Miocene) of Clifden, South Island, which differs in having a much taller, narrower spire, axial sculpture that is evident on early whorls and along the peripheral keel, and a thicker, more heavily sculptured siphonal canal. The type of C. kiosk is small (47 mm), but Finlay (1930b: 270) extrapolated that, based on fragments, this species reached about 120 mm in length. In the Recent fauna, Coluzea altocanalis resembles Coluzea kallistropha Harasewych, 2004 , from deeper waters (1,335 –1,600 m) off Mozambique. Coluzea kallistropha is distinguished by having a smaller shell (to 52 mm) with a more conical protoconch, a shorter, broader spire, a flatter shoulder, and a peripheral keel that is much wider and situated higher on the aperture.

Darragh (1969: 104, pl. 6, fig. 114) illustrated a dead and damaged specimen taken in 912–997 m off Castle Point, North Island that he provisionally identified as Fulgurofusus sp. cf. benthocallis ( Melvill & Standen, 1907). This record falls within both the geographic and bathymetric ranges of Coluzea altocanalis , and the illustration closely resembles the juvenile specimen shown in figure 69, herein. With the re-identification of this specimen as C. altocanalis , F. benthocalis remains endemic to the Scotia Sea in the southern Atlantic.

Coluzea altocanalis has a broad range in New Zealand waters. Off the eastern coast of North Island, it overlaps geographically with both C. spiralis and C. wormaldi . However, it inhabits considerably greater depths [785–880 m] than either C. spiralis [172–306 m] or C. wormaldi [91–461 m] in this region. Although the distribution of C. altocanalis overlaps with that of C. mariae off South Island and on the Chatham Rise, the two species have been collected in a single station only once, off Papanui Canyon, at a depth of 660 m [RV MUNIDA]. All of the specimens of C. mariae collected at this station were dead and worn. In other areas of geographic overlap, C. altocanalis occurred at depths 200–300 m greater that records for C. mariae .

Figures

FIGURES 35–38. Geographic distributions of species of New Zealand Coluzea. 35, Coluzea spiralis (A. Adams, 1856). The type locality is New Zealand. 36, Coluzea wormaldi Powell, 1971. 37, Coluzea altocanalis Dell, 1956. 38, Coluzea mariae Powell, 1952. = type locality. = station records.

FIGURES 39–42. Bathymetric distributions of species of New Zealand Coluzea. 39, Coluzea spiralis (A. Adams, 1856). 40, Coluzea wormaldi Powell, 1971. 41, Coluzea altocanalis Dell, 1956. 42, Coluzea mariae Powell, 1952.

FIGURES 62–76. Coluzea altocanalis Dell, 1956. 62, Apertural, 63, lateral, 64, dorsal, and 65, apical views of specimen from NMNZ M.074636, E of Cape Kidnappers, North Island [39°52.8’S, 177°36.5’E], in 785–882 m, on mud. 66, Apertural, 67, dorsal views, 68, detail of outer lip of specimen from NMNZ M.059715, northern Mernoo slope, [42°38.2’S, 176°10.5’E], in 999–984 m, on mud. 2 cm scale bar applies to figures 62–67. 69, Dorsal view of specimen from NMNZ M.074636, E of Cape Kidnappers, North Island [39°52.8’S, 177°36.5’E], in 785–882 m, on mud. 70, Apertural view of specimen from NMNZ M.059715, northern Mernoo slope, Chatham Rise [42°38.2’S, 176°10.5’E], in 999–984 m, on mud. 5 mm scale bar applies to figures 69–70. 71, Inner and 72, outer surfaces of operculum of specimen in figure 70. 73, Lateral and 74, apical views of protoconch of specimen in figure 69. Arrows indicate transition to teleoconch. 75–76, Radular ribbon of juvenile specimen in figure 70. 75, Dorsal view with lateral teeth expanded. 76, Dorsal view with lateral teeth folded. ac, anterior carina; dk, deflected keels; pk, peripheral keel; s, suture.