Triphora portoricensis Rolán & Redfern, 2008

Fernandes, Maurício Romulo, 2024, Triphoridae (Gastropoda) from Martinique sampled by the MADIBENTHOS expedition, with notes on shallow-water species from Guadeloupe, Zoosystema 46 (18), pp. 457-503 : 486-488

Triphora portoricensis Rolán & Redfern, 2008

( Figs 16 ; 17 )

“ Triphora ” portoricensis Rolán & Redfern in Rolán & Fernández-Garcés 2008: 158, fig. 32A-E.

Iniforis sp. – Redfern 2001: 66, pl. 33, fig. 278A, B.

“ Triphora ” portoricensis – Redfern 2013: 127, fig. 358A, B. — Fernandes & Pimenta 2015: 505 , fig. 6. — Fernandes & Pimenta 2020: 168 .

TYPE MATERIAL. — Holotype. Puerto Rico • sh; FLMNH 363895 . Paratype. Bahamas • 1 sh; Abaco; 26°44’00”N, 77°09’00”W; 9.IX.1987; C. Redfern leg.; depth 52 m; BMSM 55395 .

TYPE LOCALITY. — Puerto Rico.

MATERIAL EXAMINED. — Martinique. MADIBENTHOS. ‘Nord Atlantique’ • 3 sh; sta. AB350; MNHN. ‘Sud Atlantique’ • 1 sh; sta. AB183; MNHN • 1 sh; sta. AB191; MNHN • 1 sh; sta. AB193; MNHN • 1 sh; sta. AS255; MNHN • 5 sh; sta. AB405; MNHN.

GEOGRAPHIC DISTRIBUTION. — Bahamas ( Rolán & Fernández-Garcés 2008; Redfern 2013); Puerto Rico ( Rolán & Fernández-Garcés 2008); Martinique (this study); Brazil. Rio Grande do Norte to Rio de Janeiro ( Fernandes & Pimenta 2015).

BATHYMETRIC DISTRIBUTION. — Recorded depth in Martinique: 14- 23 m. Previous recorded depth in the West Atlantic: 23-100 m ( Fernandes & Pimenta 2015, 2020).

EMENDED DESCRIPTION

Shell sinistral, conical to slightly pupoid, rectilinear to slightly convex profile, reaching 3.6 mm long, 1.3 mm wide, length/ width ratio 2.6-3.1; adult shells reach at least 1.9 mm in length. Protoconch sub-columnar, slightly inflated, of 2.75- 3.25 whorls, 0.40-0.58 mm long, 0.41-0.51 mm wide, weak distinction between protoconch and teleoconch; initial 0.5 whorl smooth, but axial ribs soon appear, with their adapical part emerging on the abapical part of the smooth whorl above, assuming an irregular shape, often arrow-shaped initially but varying from sigmoid, nearly orthocline, strongly opisthocline or strongly prosocline on the last whorl, where it numbers 20-34 ribs; one main spiral cord often occupying the mid portion of the whorl (sometimes the abapical portion), situated at 44-61% of last whorl height, keel-shaped, in addition to a small sutural cord. Teleoconch with up to seven whorls; two spiral cords (adapical and abapical) at the beginning, the abapical one continuous to that of protoconch; median spiral cord emerging at the end of second whorl or at the third whorl, reaching the same size than other cords after c. 1.5 whorl; at the body whorl, the three cords being equidistant and nearly the same size; 20-21 nearly orthocline axial ribs on the fifth whorl; rounded nodules of medium size, with square interspaces among nodules; distinct suture, with a sutural cord; slightly nodulose to wavy subperipheral cord, one to two smooth basal cords, often narrow, but sometimes well-developed; no distinct supranumerical cords, but a minute spiral thread sometimes appearing between abapical and subperipheral cords prior to the peristome; aperture rounded to slightly rhomboid (with a discrete notch in the posterior end), 0.47-0.83 mm long, 0.43-0.59 mm wide, length/width ratio 1.1-1.4; anterior canal very short, open, 0.07-0.15 mm long, 0.13-0.20 mm wide, length/width ratio 0.4-0.7. White to light cream shell, with adapical spiral cord and base slightly darker.

REMARKS

The shell from Guadeloupe identified by Lamy & Pointier (2018: pl. 92, fig. 11) as Triphora portoricensis is actually the holotype of Marshallora monteiroi n. comb. Some shells of T. portoricensis from Martinique ( Fig. 16 ) resemble one shell tentatively identified as M. monteiroi n. comb. ( Fig. 7K ), but the former morph has a slightly darker adapical spiral cord of teleoconch (vs spiral cords with a more homogeneous color in M. monteiroi n. comb.) and basal cords ( Fig. 17A, E ) often considerably thinner than M. monteiroi n. comb. ( Fig. 7 L-M). Shells of T. portoricensis from Martinique vary in the adult shell length (1.9-3.6 mm) and in the axial sculpture of the protoconch, but the largest shells are similar to the holotype from Puerto Rico (4.4 mm to eight teleoconch whorls vs up to seven whorls in shells from Martinique). In contrast, shells from Bahamas and Brazil are entirely white ( Redfern 2013; Fernandes & Pimenta 2015); those from Brazil have a different teleoconch sculpture in late whorls, with a more distant adapical spiral cord (not discernible in Bahamian shells, only known by juveniles), and reach up to 10 mm to 13 teleoconch whorls ( Fernandes & Pimenta 2015). This suggests that the current concept of T. portoricensis is actually a species complex masked by the similar protoconch morphology, which could be derived from convergence or parallelism.

Figures

FIG. 16. — Triphora portoricensis Rolán & Redfern, 2008: A, MNHN, sta. AB183, 2.3 mm; B, H, MNHN, sta. AB193, 1.9 mm; C, MNHN, sta. AB350, 2.3 mm; D-F, MNHN, sta. AB405, 2.4 mm, 3.2 mm, 3.3 mm; G, MNHN, sta. AS255, 3.6 mm. Scale bars: A-G, 1 mm; H, 100 μm.

FIG. 17. — Triphora portoricensis Rolán & Redfern, 2008: A, B, MNHN, sta. AB183 (Fig. 16A); C, MNHN, sta. AB193 (Fig. 16B); D, MNHN, sta. AB350 (Fig. 16C); E, H, MNHN, sta. AS255 (Fig. 16G); F, MNHN, sta. AB405 (Fig. 16E); G, MNHN, sta. AB405 (Fig. 16F). Scale bars: A, E, 200 μm; B-D, F-H, 100 μm.

FIG. 7. — Marshallora monteiroi (Rolán & Fernández-Garcés, 2015) n. comb.: A, L, MNHN, sta. AD283, 4.2 mm; B, MNHN, sta. AS482, 2.8 mm; C, MNHN, sta. AB350, 2.0 mm; D, MNHN, sta. AD275, 3.7 mm; E-H, N, MNHN, sta. AD283, 3.0 mm, 3.0 mm, 3.5 mm, 3.0 mm; I, MNHN, sta. AS252, 3.0 mm; J, MNHN, sta. GD21 (KARUBENTHOS 1), 4.6 mm; K, M, MNHN, sta. AD263, 2.7 mm. Scale bars: A-K, 1 mm; L-N, 200 μm.