Hyperaulax ridleyi (Smith, 1890)

Salvador, Rodrigo B. & Cavallari, Daniel C., 2019, Taxonomic revision of the genus Hyperaulax Pilsbry, 1897 (Gastropoda, Stylommatophora, Odontostomidae), Zoosystematics and Evolution 95 (2), pp. 453-463 : 456

Hyperaulax ridleyi (Smith, 1890) Fig. 2

Bulimus (Bulimulus) Ridleyi E.A. Smith 1890: 501, pl. 30, fig. 9; Dall 1896: 415.

Bulimulus (Hyperaulax) ridleyi : Pilsbry 1897a: 10; Pilsbry 1897b: 82, pl. 14, figs 11-13.

Buliminus ridleyi : Möllendorff 1901: 126.

Hyperaulax ridleyi : Pilsbry 1901: 103; Ihering 1923: 191; Wenz 1923: 729; Schileyko 1999: 321, fig. 396; Salgado and Coelho 2003: 165; Simone 2006: 178, fig. 637; Breure and Ablett 2012: 36, figs 20C, D, 20ii; Salvador 2019: 87.

Hyperaulax (Hyperaulax) ridleyi : Thiele 1931: 661; Morretes 1949: 153; Zilch 1960: 505, fig. 1771; Breure 1974: 51; Breure and Schouten 1985: 4.

Hyperaulax (s. str.) ridleyi : Lopes and Alvarenga 1955: 181.

Bulimus (Bulimulus) ridleyi : Oliveira and Oliveira 1984: 19.

Type locality.

Fernando de Noronha Archipelago, Fernando de Noronha Island and Rata Island. Original ( Smith 1890: 501): "Living under bark of Mango-trees in the garden and on north side of island; also at base of the Peak, north side, under stones, and on Rat Island."

Distribution.

Known only from Fernando de Noronha Archipelago.

Type material.

Lectotype NHMUK 1888.6.27.106 (designation by Breure and Ablett 2012). Paralectotypes: NHMUK 1888.6.27.107-110, 4 shells.

Material examined.

Types. BRAZIL: Fernando de Noronha: ANSP 71271, 7 shells, H.H. Smith leg., 1896; MNZ 205835, 4 shells, ex Suter coll. 5637; ANSP 81426, 1 shell; ANSP 100530, 4 shells, H.v. Ihering leg., 1910; ANSP 220399, 2 shells, ex B.R. Bales coll., J.S. Schwengel leg., 1958; MNZ 205835,4 shells, ex Suter coll. 5637; MZSP 501, 14 shells, 1900; MZSP 7752, 20 shells. MZSP 30134, 10 shells, dunes of Praia das Caieiras, E.F. Nonato leg., 25/vii/1955; MZSP 30135, 8 shells, de Fiore leg., 1983; MZSP 31064, 1 shell, Praia do Meio, L.R.L. Simone & Souza leg. 22/vii/1999; MZSP 31305, 30 specimens, between Baía dos Porcos and Baía do Sancho, L.R.L. Simone leg., 21/vii/1999; MZSP 31676, 14 shells, Praia das Caieiras, L.R.L. Simone et al. leg., 23/vii/1999; MZSP 31681, 15 specimens, mangrove on Praia do Sudeste, C.M. Martins leg., 20/vii/1999; MZSP 31686, 50 specimens, Praia do Meio, C.M. Martins leg., 17-23/vii/1999; MZSP 48824, 1 shell, Praia do Porto, 3°50'05"S, 32°24'04"W, L.R.L. Simone leg., 30/iv/2005; MZSP 48990, 9 shells, Praia das Caieiras, 3°50'19"S, 32°24'00"W, L.R.L. Simone leg., 3/v/2006; MZSP 49001, 11 shells, mangroove on Praia do Sudeste, 3°51'58"S, 32°25'35"W, L.R.L. Simone leg., 4/v/1005; MZSP 49089, 39 shells, in front of Morro Dois Irmãos and Cacimba do Padre, L.R.L. Simone leg., 3/v/2005; MZSP 86542, 13 shells; Praia do Porto, 3°50'11"S, 32°24'04"W, L.R.L. Simone et al. leg., 28/x/2007; MZSP 89929, >50 shells, 3°50'00"S, 32°24'05"W, L.R.L. Simone & C.M. Cunha leg., iii/2009; MZSP 89933, 17 shells, L.R.L. Simone & C.M. Cunha leg., 11/iii/2009; MZSP 89939, 2 specimens; 3°50'21"S, 32°24'10"W, L.R.L. Simone & C.M. Cunha leg., 12/iii/2009; MZSP 89940, 5 specimens, Mirante, L.R.L. Simone & C.M. Cunha leg., 11/iii/2009; MZSP 89993, 1 shell, Praia do Sudeste, 3°52'06"S, 32°25'32"W, L.R.L. Simone & C.M. Cunha leg., 9/iii/2009; MZSP 97854, 3 shells, ex J. Vaz coll., A. Nüssenbaum leg., viii/1973; MZSP 97878, 3 shells, ex J. Vaz coll., Praia das Caieiras, C. Bardelli leg., vi/1994; MZSP 119089, 23 shells, Cacimba do Padre, 3°50'36"S, 32°25'14"W, L.R.L. Simone et al. leg., 8/v/2013; MZSP 119090, 29 shells, Cacimba do Padre, 3°50'36"S, 32°25'14"W, L.R.L. Simone et al. leg., 7/v/2013; NHMUK 1888.6.27.88-94, 7 shells; NHMUK 1888.6.27.95-100, 6 shells, Rata Island; NHMUK 1888.6.27.101-105, 5 shells; NHMUK 20170270, 4 shells, H.E.J. Biggs coll., H. Fiedrick leg.; USNM 134849, 1 shell, H.A. Pilsbry leg.; USNM 214401, 1 shell, H.A. Pilsbry leg.; USNM 307580, 2 shells, Henderson coll., H. Clapp leg.; USNM 518214, 3 shells, W. Williamson leg.; ZSM no nr., 2 shells, Blume coll. 4003; ZSM no nr., 4 shells, H.H. Smith coll.

Diagnosis.

The shell is smaller overall and has a more elongated and slender profile. The protoconch has a more raised ridge and its sculpture consists largely of more anastomosed riblets. Typically, there is no apertural dentition.

Description.

Shell small, bulimoid, slender; spire tall; W ~ 4¾– 5. Shell color ochre to brown; body whorl sometimes darker than rest; fine white spiral band on middle portion of whorl; periumbilical spiral angulation discolored, whitish; peristome white. Protoconch (w ~ 1¾) rounded, with raised ridge that becomes a faint subsutural ridge on teleoconch; sculptured by fine sinuous axial riblets, which sometimes anastomose (especially on abapical area of whorl); transition to teleoconch unclear. Teleoconch smooth (except for growth lines). Suture well marked, but not deep. Aperture ovoid, elongated. Peristome reflected and slightly thickened; presence of small channel-like structure on division between parietal and palatal regions of aperture; parietal callus might be present in older specimens. Apertural teeth usually absent, but faint elongated tooth on middle portion of palatal region may be present ( Fig. 2A ). Umbilicus narrow, deep, surrounded by a periumbilical spiral angulation.

Dimensions.

Lectotype: H = 11.4 mm, D = 5.9 mm, h = 4.8 mm, d = 3.0, W = 5¼, w = 1¾. Paralectotype #1: H = 9.5 mm, D = 5.3 mm, h = 4.4 mm, d = 3.0 mm, W = 4½, w = 1½. Paralectotype #2: H = 9.1 mm, D = 5.3 mm, h = 4.3 mm, d = 2.9 mm, W = 4½, w = 1¾. Paralectotype #3: H = 8.9 mm, D = 5.2 mm, h = 4.3 mm, d = 2.9 mm, W = 4½, w = 1¾. Paralectotype #4: H = 8.9 mm, D = 5.2 mm, h = 4.2 mm, d = 2.8 mm, W = 4½, w = 1¾. Average (n = 63, except for w, where n = 10): H = 10.2 ± 1.00 mm (min = 7.8 mm, max = 12.7 mm), D = 5.7 ± 0.51 mm, h = 4.9 ± 0.45 mm, d = 3.5 ± 0.34 mm, W = 4¾ to 5 (min = 4¼, max = 5½), w = 1¾ (occasionally 1½).

Remarks.

Other than showing a reasonable variation in shell size, the species displays little conchological variation ( Fig. 2 ). Rare specimens, however, do deviate from the typical form, for instance by having broader shells with shorter spires ( Fig. 2 F–I ) or by having a palatal tooth ( Fig. 2A , lectotype). The color might vary from more ochre tones to more reddish-brown ones, but the single white spiral band on the mid-section of the whorl is always present. Hyperaulax ridelyi can be easily distinguished from its only congener, H. ramagei , by its smaller shell (with a single spiral white band) and more elongated and slender shell profile. Moreover, its protoconch has a more raised ridge and the riblets of its sculpture are much more anastomosed. Finally, H. ridleyi typically bears no apertural dentition (although a weak palatal tooth might be present; Fig. 2A ).

Unfortunately, not much can be found in the literature about this species’ habitat or habits, but the museum labels point to a variety of collection locales, albeit more usually referring to dead shells only. In any event, this species has been reported alive from forested areas, mangrove, beaches, dunes, and gardens.

Figures

Figure 2. Hyperaulax ridleyi. A-E. Lectotype, NHMUK 1888.6.27.106. F-I. Paralectotypes 1 to 4 (in order), NHMUK 1888.6.27.107 - 110. J. Extreme form, large and with thick callus, NHMUK 1888.6.27.88 - 94. K. Weathered specimen, ZMS unnumbered (ex Heimburg colln.). L. Protoconch detail (same specimen from K).