Triphora portoricensis Rolán & Redfern, 2008

Fernandes, Maurício R. & Pimenta, Alexandre D., 2015, Five new species and two records of Triphorinae (Caenogastropoda, Triphoridae) from Brazil, Zootaxa 4012 (3), pp. 493-513 : 505-507

Triphora portoricensis Rolán & Redfern, 2008

( Figure 6 )

Iniforis sp. : Redfern (2001: 66, plate 33, figures 278A–B).

“ Triphora ” portoricensis Rolán & Redfern in Rolán & Fernández-Garcés (2008: 158, figures 32A–E); Redfern (2013: 127, figures 358A–B).

Type material. Holotype: FLMNH 363895. Paratype: BMSM 55395 [1].

Type locality. Puerto Rico.

Material examined. Bahamas: BMSM 55392, Abaco, 60 m, C. Redfern coll., 06/viii/1982 [1]; BMSM 55393, Abaco, 53 m, C. Redfern coll., 09/ix/1987 [1]; BMSM 55394, Abaco, 52 m, C. Redfern coll., 09/ix/1987 [4]; BMSM 55395, Abaco, 52 m, C. Redfern coll., 09/ix/1987 [1, paratype]; BMSM 55396, Abaco, 35 m, C. Redfern coll., 28/vi/1996 [1]. Brazil: Rio Grande do Norte state: MNRJ 31590, BPot 2-MR45 [2]. Bahia state: MNRJ 32880, Boipeba, 02/iv/2003 [1]; MNRJ 32897, 13º27’43”S, 38º49’27”W, v/2007 [3]; MNRJ 32997, 13º28’58”S, 38º48’21”W, vi/2010 [1]; MNRJ 32614, 13º28’58”S, 38º48’16”W, ix/2007 [1]; MNRJ 33084, 13º29’44”S, 38º48’19”W [2]; MORG 52593, off Camamú, 52 m, 11/xii/2002 [3]; MORG 52592, Abrolhos, Eq. MORG coll., ii/ 1978. Espírito Santo state: MNHN, Expedition MD55 sta. DC83, 18º50’S, 37º57’W, 60 m, v/1987 [1]; IBUFRJ 9105, REVIZEE C1-C65 [1]; MNRJ 17229, 19º25’37”S, 39º22’22”W, 43 m, x/2003 [1]; MNRJ 30929, 19º26’00”S, 39º22’30”W, 55 m, x/2003 [1]; MNRJ 34025, 20º42’00’’S, 40º24’28’’W, Ilha Escalvada, Guarapari, 2012 [1]; MNRJ 31061 [1], MNRJ 31089 [1]: 20º47’S, 40º34’W, iii/2010; MNRJ 33024, 20º47’S, 40º34’W, ix/ 2007 [4]; IBUFRJ 8682, Piúma, 1993 [1]. Rio de Janeiro state: MNRJ 18707, HAB 13-H3 [1]; MNRJ 17228, 23º05’S, 40º58’W, 100 m, 17/ix/2004 [1].

Description. Shell sinistral, elongated, conical, profile rectilinear, reaching 10.00 mm in length (apex missing), 2.54 mm in width. White shell. Protoconch sub-trapezoidal, 0.55–0.70 mm in length, 0.47–0.55 mm in width, with 3 to 3.5 whorls, weak distinction between protoconch and teleoconch; apex pointed, abrupt, without apparent sculpture; larval shell with a thick and keel-shaped abapical spiral cord, situated near suture, adapical spiral cord slowly emerging at end of protoconch; small, irregular and incomplete axial ribs especially concentrated on adapical portion of whorl, being more numerous and closer towards end of larval shell. Teleoconch with up to 13 whorls; two spiral cords (adapical and abapical) on first whorl, both continuous with those of protoconch; median spiral cord emerges in second whorl, eventually at the beginning of third whorl, reaching same size than other cords after half to one whorl; after fifth/sixth whorl, adapical spiral cord becomes distant from other cords and with a less pronounced profile; 16 to 20 slightly opisthocline axial ribs; rounded nodules of medium size; large and squarish interspaces among nodules; distinct and very well developed suture, with a wide sutural cord present from its origin on protoconch; narrow and slightly wavy to little nodulose subperipheral cord, two narrow and slightly wavy basal cords; a small supranumerical cord may form between abapical spiral cord and subperipheral cord; aperture elliptical; anterior canal with medium size, directed downward/backward, partially open but crossed in its base by projection of outer lip; posterior canal as a small notch, not detached from aperture.

Remarks. After comparing shells of T. portoricensis from Bahamas ( Fig. 6 A–B) and Brazil ( Fig. 6 C–K), we found no significant differences between them. Regarding the teleoconch, the adapical spiral cord is only faintly isolated from other cords in the Caribbean shells examined because these consist mostly of juveniles, without enough whorls to have this pattern of spiral cords. Caribbean shells reach 4.4 mm with eight teleoconch whorls ( Rolán & Fernández-Garcés 2008), instead of 10.0 mm with 13 teleoconch whorls in Brazilian shells; however, shells with eight teleoconch whorls from Brazil are similar in length to those from the Caribbean. The color of the holotype, described as light brown with a white apex ( Rolán & Fernández-Garcés 2008), is typical of worn material, as shells of this species are actually white ( Redfern 2013). Owing to the very scarce available material of T. portoricensis from Caribbean, mostly consisting of juveniles, more sampling of this species is required to further comparisons.

The protoconch of Inella obtusa Marshall, 1983 , a species from the southwestern Pacific, resembles T. portoricensis , but probably due to convergence. The atypical protoconch morphology of T. portoricensis ( Fig. 6 I– J) is possibly indicative of a multispiral type derived from intracapsular metamorphosis.

Geographic distribution. Bahamas ( Rolán & Fernández-Garcés 2008; Redfern 2013); Puerto Rico (type locality); Brazil: Rio Grande do Norte, Bahia to Rio de Janeiro (present study).

Bathymetric distribution. 35 m ( Redfern 2013) to 100 m (present study). This species is found in waters shallower than 35 m, but in these cases the bathymetric data is inaccurate.

Figures

FIGURE 6. Triphora portoricensis. A. BMSM 55396, shell from Bahamas, 3.07 mm long. B. BMSM 55394, idem, 2.13 mm long. C. IBUFRJ 9105, shell from Brazil, 8.86 mm long. D. MNRJ 17228, idem, 6.70 mm long. E – G, I, same shell as D. H, J – K, MNRJ 32880. Scale bars: A – E, 1 mm; F – H, 500 µm; I – K, 100 µm.