Eutriphora Cotton & Godfrey, 1931

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 : 498-500

Eutriphora Cotton & Godfrey, 1931

Type species. Triphora cana Verco, 1909 ; original designation. Recent, southern Australia.

Diagnosis. Paucispiral or multispiral protoconch; paucispiral protoconch blunt-ending with spiral cords of thick, sometimes elongate nodules; multispiral protoconch with embryonic shell minutely granulose and larval shell with axial ribs crossed by two spiral cords; median spiral cord of teleoconch emerges later; presence of supranumerical cords; anterior canal open or subtubular (partly based on Wilson 1993).

Remarks. The genus has up to now six species worldwide ( Bouchet & Rosenberg 2014a), two in the western Atlantic ( Rosenberg 2009).

Eutriphora costai sp. nov. ( Figure 3 )

Type material. Holotype: MNRJ 32604, ix/2007. Paratypes: Brazil: Almirante Saldanha Seamount: MNRJ 33764, REVIZEE C1-D1 [2]. Rio de Janeiro state: MNRJ 32051, 23º03’18”S, 41º02’06”W, 97 m, x/2008 [1]; MNRJ 32066, 23º15’00”S, 41º06’00”W, 112 m, x/2008 [2]; MNRJ 32544, 23º05’S, 40º58’W, 100 m [2].

Material examined of Eutriphora auffenbergi Rolán & Lee, 2008 : holotype, FLMNH 419186.

Type locality. 13º28’58”S, 38º47’51”W, 40 m, Bahia state, Brazil.

Etymology. This species is named in honor to our dear friend, Dr. Paulo Márcio Santos Costa, who helped us several times through loan of material and precise collection data.

Diagnosis. Median spiral cord emerges on fifth teleoconch whorl; elongated anterior canal; beige coloration of shell, protoconch darker than teleoconch.

Description. Shell sinistral, elongated, conical, profile slightly curvilinear, reaching 6.50 mm in length, 1.87 mm in width. Cream shell, protoconch darker than teleoconch. Protoconch conical, 0.46–0.53 mm in length, 0.36– 0.40 mm in width, with about five convex whorls; embryonic shell dome-shaped, covered by rounded granules; larval shell with two spiral cords, but adapical one disappearing just before the transition to teleoconch; about 34 almost rectilinear to slightly sigmoid axial ribs. Teleoconch with up to 11 whorls; two spiral cords (adapical and abapical) on the first whorl, abapical one continuous with that of protoconch; median spiral cord emerges in the beginning of fifth whorl, reaching same size than other cords after 2 to 2.5 whorls; 20 to 22 opisthocline axial ribs; rounded nodules of medium size; distinct and well developed suture, with a small sutural cord; smooth subperipheral cord and two smooth basal cords; four supranumerical cords in the last whorl, one between adapical and median spiral cords, another between median and abapical spiral cords, another between abapical and subperipheral cords, the last between subperipheral and adapical basal cords; aperture ovate, with a projecting outer lip; anterior canal curved backward/downward, being long and almost closed, crossed at its base by projection of outer lip; posterior canal as a deep sinus, not detached from aperture.

Remarks. Eutriphora costai sp. nov. is similar to Eutriphora auffenbergi Rolán & Lee, 2008 , a species up to now restricted to Florida, U.S. A ( Rolán & Fernández-Garcés 2008, Lee 2009), especially regarding the sculpture of protoconch, the emergence of the median spiral cord of the teleoconch, shell color and the long anterior canal. The primary differences consist of the sutural cord (small and partially hidden in the suture of E. costai , Fig. 3 F; large and exposed in E. auffenbergi ), the subperipheral cord (smooth in E. costai , Fig. 3 H; moderately nodulose in E. auffenbergi ), shell dimensions (up to 6.50 mm long, 11 teleoconch whorls in E. costai ; up to 21.8 mm long, 17–18 teleoconch whorls in E. auffenbergi ), more crowded nodules on the teleoconch and smaller anterior canal in E. costai .

Even without knowledge of radula and anatomy, E. costai is allocated in Eutriphora by great similarities of protoconch and teleoconch with E. auffenbergi and Eutriphora armillata ( Verco, 1909) , the latter illustrated in Marshall (1983). The type species, Eutriphora cana ( Verco, 1909) , has a paucispiral protoconch, precluding further comparisons. The present generic allocation may be provisional, pending knowledge of soft bodies of E. costai .

Geographic distribution. Brazil: Bahia, Almirante Saldanha Seamount, Rio de Janeiro.

Bathymetric distribution. 40 to 112 m.

Figures

FIGURE 3. Eutriphora costai sp. nov. A. MNRJ 32604, holotype, 6.50 mm long. B. MNRJ 32544, paratype, 6.03 mm long. C. MNRJ 32066, paratype, 5.26 mm long. D. MNRJ 32544, paratype, 5.70 mm long. E – K, same shell as D. Scale bars: A – E, 1 mm; F – H, 500 µm; I, K, 100 µm; J, 50 µm.