Nanaphora leei, Fernandes, Maurício R. & Pimenta, Alexandre D., 2015

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 : 503-505

Nanaphora leei sp. nov.

( Figure 5 )

Type material. Holotype: MNRJ 34086, A. Bodart coll., ix/1993. Paratypes: Brazil: Rio de Janeiro state: MNRJ 29765, 22º42’S, 40º40’W, 2007 [2].

Other material examined. Brazil: Espírito Santo state: MNRJ 32645 [3], MNRJ 32653 [1], MNRJ 32665 [1]: 20º14’S, 40º12’W, vi/2008; MNRJ 31015, 20º47’S, 40º34’W, x/2008 [1]; MNRJ 31009, 20º47’S, 40º34’W, xi/ 2009 [1].

Type locality. Praia de Meaípe, 20–25 m, Guarapari, Espírito Santo state, Brazil.

Etymology. This species is named in honor of Dr. Harry G. Lee, owing to his effort in the research of marine mollusks, including triphorids, and to the donation of shells (like the holotype of the present species) from his private collection.

Diagnosis. Shell large for the genus, but with a small-sized protoconch; median spiral cord emerges between eighth and ninth whorl of teleoconch.

Description. Shell sinistral, elongated, conical, profile slightly curvilinear, reaching 5.83 mm in length, 1.80 mm in width. Protoconch golden; teleoconch with brown to light brown background, whitened nodules; first two whorls of teleoconch lighter in color than remaining whorls; adapical spiral cord may be somewhat darker than other cords. Protoconch conical, 0.41–0.45 mm in length, 0.30–0.35 mm in width, with 4.5 convex whorls; embryonic shell dome-shaped, with a reticulated pattern of spiral and axial threadlets; larval shell with two spiral cords, adapical one weakening in last whorl and disappearing just before transition to teleoconch; about 36 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 eighth whorl or between eighth and ninth whorl, as a very fine cord bordering the adapical one, but reaching same size than other cords after 1.5 to 2.5 whorls; 18 to 21 axial ribs, with undulating arrangement varying from slightly prosocline (or nearly orthocline) to slightly opisthocline; large rounded nodules; barely distinct suture, with a small sutural cord; nodulose subperipheral and adapical basal cords, wavy abapical basal cord; two supranumerical cords in the last whorl, one between median and abapical spiral cords, the other between abapical and subperipheral cords; aperture elliptical; anterior canal curved backward/downward, being small and open, but crossed on its base by projection of outer lip; posterior canal as a deep sinus, almost detached from aperture in some cases.

Remarks. Shells of Nanaphora leei sp. nov. can be barely separated in two groups: those shells with slightly larger and close nodules on the teleoconch, in addition to very nodulose subperipheral and adapical basal cords; and those with slightly smaller and separate nodules on the teleoconch in addition to equally or less nodulose subperipheral and adapical basal cords. The first group is represented by the type material ( Fig. 5 A–C), and the second usually consists of worn material, listed as additional material examined ( Fig. 5 D). Notwithstanding, we believe that they are the same species.

Nanaphora leei shares many features with N. verbernei , like the presence of large nodules, barely distinct suture, short base and anterior canal, nodulose subperipheral and adapical basal cords, undulating axial ribs, and similar coloration. Differences include the length of the adult shell (reaching 5.83 mm in N. leei , 3.66 mm in N. verbernei ), length of the protoconch (0.41–0.45 mm in N. leei , 0.45–0.55 mm in N. verbernei ), shape of the shell ( N. leei is never ovoid as some shells of N. verbernei ), and emergence of the median spiral cord (between eighth and ninth whorl in N. leei , between end of fifth to seventh whorl in N. verbernei ). Nanaphora leei also presents a restricted geographic distribution.

Nanaphora decollata is also similar to N. leei and is reported only from the Caribbean; N. decollata is smaller (up to 3.95 mm in length), having a darker protoconch, granulose embryonic shell (not reticulated as in N. leei ), and different coloration. Monophorus ateralbus Rolán & Fernández-Garcés, 1994 , also reported only from the Caribbean, has a very heterogeneous teleoconch coloration (brown adapical and median spiral cords, white abapical cord) and earlier emergence of the median cord (between the sixth and seventh whorls). Shells of N. leei with broken apices may resemble Coriophora novem ( Nowell-Usticke, 1969) , a western Atlantic species (illustrations in Rolán & Fernández-Garcés 1995 and Fernandes et al. 2013); differences are related to color of nodules (whitened in N. leei , violet/greyish in C. novem ), suture (less distinct in N. leei ), and shape of axial ribs (undulating in N. leei , severely opisthocline in C. novem ).

Laseron (1958) proposed that the genus Nanaphora has shells less than 5.0 mm in length. With the exception of Nanaphora truncis Laseron, 1958 (reaching up to 6.0 mm), N. leei is the largest species of the genus, reaching 5.83 mm in shell length.

Geographic distribution. Brazil: Espírito Santo to Rio de Janeiro.

Bathymetric distribution. 20 to 25 m.

Figures

FIGURE 5. Nanaphora leei sp. nov. A. MNRJ 34086, holotype, 5.83 mm long. B. MNRJ 29765, paratype, 4.87 mm long. C. MNRJ 29765, paratype, 3.20 mm long. D. MNRJ 32653, 4.96 mm long. E – F, I – K, same shell as B. G – H, holotype, not coated for SEM. Scale bars: A – E, 1 mm; F – H, 500 µm; I, K, 100 µm; J, 50 µm.