Turbonilla puncta ( C. B. Adams, 1850 )

Pimenta, Alexandre D. & Absalão, Ricardo S., 2002, On the taxonomy of Turbonilla puncta (C. B. Adams, 1850) (Gastropoda, Pyramidellidae), with the description of a new species from Brazil and remarks on other western atlantic species, Zootaxa 78, pp. 1-16 : 3-7

Turbonilla puncta ( C. B. Adams, 1850) ( Figs. 1­12 )

Chemnitzia puncta C. B. Adams, 1850: 72 ; Krebs (1867: 395).

Turbonilla puncta: Tryon (1886: 331, pl. 76, fig. 22); Bush (1899: 162); Clench & Turner (1950: 333); Jong & Coomans (1988: 127); Odé (1996: 53); Redfern (2001: 148, pl. 66, figs. 615A, B).

Not Turbonilla puncta ( C. B. Adams, 1850) : Abbott (1974: 306, fig. 3775) (= sp. indet.).

Pyrgostelis puncta: Verrill & Bush (1900: 530, pl. 64, fig. 19, 19a).

Turbonilla (Strioturbonilla) peilei Dall & Bartsch, 1911: 280 , pl. 35, figs. 6, 6a. (new synonymy).

Turbonilla (Strioturbonilla) haycocki Dall & Bartsch, 1911: 280 ­281, pl. 35, figs. 9, 9a; Rios (1975: 145, pl. 43, fig. 676; 1985: 167, pl. 55, fig. 799; 1994: 190, pl. 62, fig. 893). (synonymyzed by Jong & Coomans, 1988).

Turbonilla (Pyrgiscus) alfredi Abbott, 1958: 104 , text fig. 5 (1a­c). Abbott (1974): 307, fig. 3789. (new synonymy).

Turbonilla cf. puncta: Diaz & Puyana (1994: 239, pl. 69, fig. 955).

Type Locality: Jamaica; neotype from: Grand Cayman Islands.

Type material: Turbonilla puncta : Type lost ( Clench & Turner, 1950). Neotype (here designated): holotype of Turbonilla alfredi ANSP 198692, South End of North Sound, Grand Cayman Islands (9 feet), 1/xi/1954, A.J.Ostheimer coll.; Turbonilla alfredi : paratype, ANSP 198693, South end of North Sound, Grand Cayman Island; Turbonilla peilei : syntype, USNM 221610, Bermuda, Haycock coll.; Turbonilla haycocki : syntype, USNM 221611, Bermuda, Haycock coll.

Material Examined: The types and: ANSP 88719, North Rock, Bermuda; ANSP 105601, Dingles Bay, Harrington Sound, Bermuda. Arthur Haycock coll. [2]; ANSP 371203, Dead Man’s Reef, Grand Bahama Island, Bahamas Islands, J.Worsfold coll. [12]; USNM 55221, Samana Bay, Dominica; ZMA, [+100] Aruba, West Indies, F.Verberne coll. [1]; IBUFRJ 9722, off Bahia State, Brazil, L.Trinchão coll. [2].

Redescription: Shell elongate and conical, white or golden­brown with one white spiral band in the middle of each whorl. Teleoconch with up to 12 slightly convex whorls. Protoconch of type A­I, with around 2.5 whorls, forming an angle of about 100 to shell main axis. Axial ribs straight and usually orthocline, sometimes opisthocline. Base with variably expressed axial ribs, never reaching the umbilical region; axial ribs projected on the posterior suture, which becomes somewhat waved; 18 to 23 ribs on 7th whorl; interspaces as wide as the ribs. Spiral sculpture consisting of numerous (about 35) closelypacked and very fine striae; a line of wider and deeper striae is present along the middle of each whorl and another just above each suture; Base rounded, with very fine waved spiral striae; without umbilical fissure. Aperture rhomboid. Columellar fold, quite obsolete. Neotype with 12 teleoconch whorls. Dimensions of neotype: length: 5.6 mm; width: 1.3 mm; protoconch width: about 250 m.

Remarks: The original description of T. puncta is clear regarding the pattern of spiral sculpture: “... numerous crowded spiral striae in the intercostal spaces, one of which striae [sic], a little above the middle of the whorls, and another along the suture are wide and deep... ”. This pattern (figs. 7, 15) was described by Powell (1981) as X(n1) Y (n2), where X and Y are the wider and deeper grooves, while n1 and n2 represent the finer striae. As noted by Powell (1981), there are variations, especially in the number and spacing of the finer striae and in the width as well as degree of prominence of the wider grooves.

The holotype of T. alfredi Abbott, 1958 (figs. 1, 6) fits the original description of T. puncta . This type­specimen was also compared to the description and the illustrations of this species published by Verrill & Bush (1900) and Jong & Coomans (1988) and to material identified as T. puncta deposited in ANSP and ZMA.

Following the rules and recommendations of the International Code of Zoological Nomenclature (I.C.Z.N. 1999: art. 75), we designate the holotype of T. alfredi as neotype for T. puncta due to the good conservation and type status already established of this specimen. Also, its type locality (Grand Cayman Island) is close to Jamaica (type locality of T. puncta ). Turbonilla alfredi therefore becomes a junior subjective synonym of T. puncta .

C. B. Adams (1850) stated that the ribs of T. puncta are not produced below the convexity of the last whorl. We noted a certain intraspecific variation in the prominence of the ribs extending onto the base. In some of the specimens studied, the ribs abruptly stop at the body whorl, not invading the base; in others, there are faint developed ribs on the base, more or less conspicuous depending on the specimen, but never reaching the umbilical region (figs. 1­4, 6­8).

The degree of inclination of the axial ribs of T. puncta also exhibits intraspecific variation, with ribs which can be orthocline or opisthocline, sometimes in the same specimen (figs. 2, 3).

Turbonilla peilei Dall & Bartsch, 1911 was described after examining two specimens which the authors called “cotypes”. One specimen was deposited at the Bermuda Museum, and the other, illustrated in their paper, was deposited at the USNM (no. 221610). We examined the later (figs. 9, 10) and concluded that it is identical to our concept of T. puncta . The more slender outline of typical T. peilei falls within the range of variation of T. puncta .

Powell (1981) suggested that T. peilei and T. haycocki are closely related, while Jong & Coomans (1988) considered T. haycocki a synonym of T. puncta and Redfern (2001) considered probable that T. puncta and T. peilei are conspecific. The original description of Turbonilla haycocki Dall & Bartsch, 1911 mentions four “cotypes”. One of them, deposited at USNM (no. 221611), is illustrated here (figs. 11, 12) and it is, indeed, very similar to T. puncta . The greater spire angle and the markedly opisthocline axial ribs of the illustrated syntype of T. haycocki fall within the intraspecific variation of the spire angle (7.5 to 12), and of the inclination of the axial ribs (figs. 1­4, 9, 11).

Turbonilla puncta has a protoconch diameter which ranges from 224 m to 269 m (mean diameter: 252 m, n = 19). Both the neotype of T. puncta and the illustrated syntype of T. peilei (the illustrated syntype of T. haycocki has a broken apex) bears protoconch diameters falling in this range (256 m in the lectotype of T. peilei and 250 m in the neotype of T. puncta ).

Odé (1996) does not agree with the synonymy between T. puncta and T. haycocki suggested by Jong & Coomans (1988) and here supported. Also, Odé (1996) considers the followings synonymies: T. puncta and Turbonilla virginica Henderson & Barsth, 1914 ; T. peilei and Turbonilla subulata ( C.B.Adams, 1850) ; T. haycocki and Turbonilla lillybeckae Usticke, 1969 ; and T. alfredi and Turbonilla vaughani Bartsch, 1955 . Such synonymys proposed by Odé (1996) could not be verified in the present study.

Verril & Bush (1900) specifically excluded Tryon's figures (1886: pl. 76, fig. 22) from their synonymic list for T. puncta , without giving an explicit explaination. However, both Tryon's and Verrrill & Bush's figures of T. puncta fit very well in the concept of T. puncta herein considered.

Figures

FIGURES 1 ­ 8: Turbonilla puncta (C. B. Adams, 1850). 1 ­ Turbonilla puncta (neotype = holotype of Turbonilla alfredi Abbott, 1958 (ANSP 198692), length: 5.6 mm; 2 ­ whole shell (ANSP 371203), length: 4.2 mm; 3 ­ whole shell (IBUFRJ 9722), length: 5.1 mm; 4 ­ whole shell (IBUFRJ 9722), length: 5.5 mm; 5 ­ protoconch (IBUFRJ 9722); 6 ­ detail of base of neotype; 7 ­ detail of last two whorls (IBUFRJ 9722); 8 ­ last whorl (IBUFRJ 9722). Scale bars: 6: 200 m; 5, 7, 8: 500 m.

FIGURES 9 ­ 12: Turbonilla puncta (C. B. Adams, 1850). 9 ­ Syntype of Turbonilla peilei Dall & Bartsch, 1911 (USNM 221610), length: 6.8 mm; 10 ­ base of syntype of T. peilei; 11 ­ syntype of Turbonilla haycocki Dall & Bartsch, 1911 (USNM 221611), length: 5.5 mm; 12 ­ base of syntype of T. haycocki. Scale bars: 500 m.