Terebra colombiensis, Simone & Gracia, 2006

Simone, Luiz Ricardo L. & C., Adriana Gracia, 2006, Two New Species Of Terebra (Gastropoda, Conoidea) From Colombia, Papéis Avulsos de Zoologia 46 (11), pp. 125-132 : 126

Terebra colombiensis new species

( Figs. 1-15 , 26, 27 )

Types – Holotype INV MOL2389. Paratypes: COLOM- BIA. La Guajira; off Dibulla , 11°28’49.2”N 73°23’58.2”W , 308 m depth, 3 shells, INV MOL3146, (sta. E24, 25 /xi/1998); off Palomino , 11°26’13.2”N 73°33’00”W , 306-312 m depth, INV MOL3185, 3 shells (sta. E26, 26 /xi/1998). Magdalena; off Neguange , 11°24’59.4”N 74°10’48”W , 304-306 m depth, INV MOL3427, 7 shells (sta. E35, 02 /xii/1998), 296-304 m depth, 11°24’42.6”N 74° 09’37.8”W, INV MOL3445, 7 shells (sta. E36, 02 /xii/1998); off Punta Gloria , 11°11’45”N 74°17’33”W , 282- 274 m depth, INV MOL1960, 1 shell (sta. E46, 04 /xii/1998). Atlántico; off Bocas de Ceniza, 11°05’15.6”N 75°15’19.8”W , 318- 314 m depth, INV MOL1962, 3 shells (sta. E49, 06 /xii/1998), 11°05’10.8”N 75°15’23.4”W, 312-326 m depth, INV MOL1963, 1 shell (sta. E50, 06 /iv/1998).

Type locality – COLOMBIA. Magdalena; off Bahía Concha , 11°22’74”N 74°10’50”W, 150 m depth (sta. E122, 19 /iii/2001).

Diagnosis

Protoconch with 1.5 whorls. Teleoconch sculptured by broad axial and spiral ribs, both equally strong or two subsutural spiral ribs broader; from 17 to 22 axial and 3-4 spiral ribs in penultimate whorl. Two subsutural spiral ribs outstandingly larger, well-marked, or rarely similar to remaining ribs. A pair of middle columellar folds.

Description

Shell ( Figs. 1-15 , 26, 27 ) – Long, slender, turriform, small (about 16 mm), up to 15 convex whorls; color pale cream to beige. Approximate spire angle between 16 and 19°. Protoconch ( Figs. 4 , 10 , 26 ) with 1.5 whorls, convex, smooth; first whorl slightly broader; transition with teleoconch indistinct. Sculpture of firsts teleoconch whorls ( Figs. 3, 4 , 9, 10 ) broad to narrow and interrupted axial ribs, each one with a subsutural node; spiral ribs gradually becoming continuous, 3-4 in penultimate whorl, subsutural nodes clearly larger than others, nodes on spiral rib immediately below subsutural spiral rib also larger, but not as large as those on subsutural rib ( Figs. 7-9, 12 , 27 ); rarely (1 each 20) subsutural nodes similar in size to others; ( Figs. 1-3, 6 , 27 ) between 17-22 axial ribs in penultimate whorl; with similar width as axial ribs; a small node at intersection of spiral and axial ribs. Aperture simple ( Figs. 5, 6 , 12, 13 ); outer lip edged; inner lip smooth, sigmoid, possessing pair of oblique, low folds located in middle region, inferior fold continuous with inner edge of canal ( Fig. 13 ). Canal short, somewhat widely opened, weakly curved, preceded by short narrow region.

Measurements (in mm) – Holotype INVMOL 2389: 16.60 by 3.30; INVMOL 1963: 15.45 by 3.70; INVMOL 1962: 15.66 by 3.70 ( Fig. 14 ), (2 other shells): length 16.25; 11.31 resp.; INVMOL 3427 (7 shells measured): length 12.88; 11.96; 10.95; 0.96; 12.78; 10.57; 9.40 respectively; INVMOL 1961 (2 shells measured): length 16.14; 9.01 resp.; INVMOL 3146 (3 shells): length 13.22; 12.64; 9.82; INVMOL 3146 (8 shells): length 9.76; 9.87; 8.76; 10.11; 9.49; 8.02; 8.83; 8.70; resp.; INVMOL 3185 (11 shells): length 10.77; 10.09; 11.6; 11.87; 10.18; 9.98; 9.55; 8.71; 11.81; 8.92; 8.48 resp.

Distribution – Colombian Caribbean coast, from La Guajira to Atlántico.

Habitat – Upper slope and continental shelf soft bottoms, from 150 to 314 m depth (shells only).

Material examined – Types. Additional material: CO LOM- BIA. La Guajira; off Palomino, 11°26’13.2”N 73°33’00”W, 306-312 m depth, MZSP 64444, 5 shells (sta. E26, 26 /xi/1998; ex-INV MOL3185). Magdalena; off Neguange, 11°24’42.6”N 74° 09’37.8”W, MZSP 64445, 4 shells (sta. E36, 02 /xii/1998; ex-INV MOL3445); off Punta Gloria, 11°11’45”N 74°17’33”W, 282- 274 m depth, MZSP 64446, 1 broken shell (sta. E46, 04 /xii/1998; ex-INVMOL 1960). Atlántico; off Bocas de Ceniza , 11°05’15.6”N 75°15’19.8”W, 318- 314 m depth, 2 shells, MZSP 64447, (sta. E49, 06 /xii/1998; ex-INVMOL 1961) .

Etymology. The specific epithet refers to the country of occurrence, Colombia.

Figures

Figuras 1-6. Terebra colombiensis paratype INVMOL 1963, as an example of a specimen with uniform sculpture: 1) frontal view; 2) dorsal view; 3) frontal view in SEM; 4) derail of apical region of shell, SEM; 5) detail of aperture, frontal-slightly oblique view; 6) detail of last whorl, SEM, frontal view. Total length = 15.45 mm.

Figuras 7-15. Terebra colombiensis holotype and paratypes: 7-13) Holotype; 7) dorsal view; 8) frontal view; 9) frontal view in SEM; total length = 16.6 mm; 10) detail of apical region of shell, SEM; 11) detail of middle region of shell, showing sculpture; 12) detail of penultimate whorl, frontal view; 13) same, SEM, slightly oblique view; 14) paratype INV MOL 1962, frontal view, length = 15.66 mm; 15) paratype INV MOL 3427, length = 12 mm.

Figuras 22-27. Terebra spp shells: 22-25) Terebra sterigmoides paratypes; 22-23) INV MOL5479, frontal and dorsal views, length = 24.23 mm; 24) INV MOL5480, SEM, detail of protoconch and first teleoconch whorl in profile, scale = 0.1 mm; 25) same, detail of middle region of spire, scale = 1 mm; 26-27) T. cobombiensis holotype, SEM; 26) shell apex in profile, scale = 0.1 mm; 27) detail of middle region of spire, scale = 1 mm.