Polyschides tetraschistus (Watson, 1879)

Caetano, Carlos Henrique Soares, Scarabino, Victor & Absalão, Ricardo Silva, 2006, Scaphopoda (Mollusca) from the Brazilian continental shelf and upper slope (13 º to 21 ºS) with descriptions of two new species of the genus Cadulus Philippi, 1844, Zootaxa 1267, pp. 1-47 : 32-33

Polyschides tetraschistus (Watson, 1879)

Figs. 64–65

+ Siphodentalium tetraschistum Watson 1879: 521 ; 1886: 15, pl. 2, fig. 8a–d.

+ Siphonodentalium quadridentatum Dall 1881: 36 .

+ Cadulus incisus Bush 1885: 471 , pl. 45, fig. 20.

+ Cadulus quadridentatus: Dall 1889: 428 , pl. 27, fig. 5; Mathews and Rios 1969: 27; Rios 1969: 7; Scarabino 1980: 12, fig. 1b.

Cadulus tetrodon (non Pilsbry & Sharp 1897): Castellanos 1970:167, pl. 1, fig. 15.

+ Cadulus tetraschistus: Scarabino 1980: 12 , fig. 1a.

+ Cadulus (Polyschides) tetraschistus: Pilsbry and Sharp 1898: 148 , pl. 23, fig. 1; Henderson 1920: 97, pl. 17, fig. 1; Lange de Morretes 1949: 52; Turner 1955: 314; Penna­Neme 1974: 114; Scarabino 1975: 182, pl. 58, fig. 889; 1985: 202, pl. 73, fig. 1033; Cabral and Mello 1994: 42, figs.15, 16.

+ Cadulus (Polyschides) tetraschistus var. quadridentatus: Pilsbry and Sharp 1898: 149 , pl. 25, fig. 1.

+ Cadulus (Polyschides) tetraschistus var. incisus: Pilsbry and Sharp 1898: 149 , pl. 25, fig. 1.

+ Cadulus (Polyschides) quadridentatus: Henderson 1920: 97 , pl. 17, figs. 2, 3; Maury 1922: 40; Lange de Morretes 1949: 52; Turner 1955: 315; Warmke and Abbott 1961: 220, fig. 34c; Abbott 1974: 389, fig. 4545.

+ Cadulus (Polyschides) quadridentatus quadridentatus: Henderson 1920: 99 .

+ Cadulus (Polyschides) quadridentatus acompusus: Henderson 1920: 100 , pl. 17, fig. 4.

Cadulus (Polyschides) tetrodon (non Pilsbry & Sharp 1897): Carcelles 1944: 468; Carcelles and Parodiz 1938: 262, pl. 1, fig. 1.

+ Polyschides tetraschistus: Díaz and Puyana 1994: 257 , pl. 71, fig. 1048; Scarabino 1994: 310, pl. 107, fig. 1522; Redfern 2001: 191, pl. 76, fig. 785; Steiner and Kabat 2001: 448; 2004: 655; Absalão and de Paula 2004: fig. 1c; Absalão et al. 2005: 177, fig. 4; Caetano and Absalão 2005: figs. 5–8.

Type material

Holotype BMNH 1887.2.9.66.

Type locality

anchorage off Fernando de Noronha, Island, Challenger sta 113a, 03º57’S, 32º24’30"W, 13–46 m (by original designation).

Diagnosis

shell small (to 9 mm), translucent, slightly curved. Maximum diameter neighborhoods oral aperture. Section circular. Apex with four notorious lobes. Oral aperture circular in section.

Material examined

Holotype of Polyschides tetraschistus ; IBUFRJ 14280, sta 48, 5 dd; IBUFRJ 14281, sta VV31, 3 dd; IBUFRJ 14282, sta VV16, 3 dd; MORG 40456, sta VV31, 6 dd.

Distribution

USA: North Carolina (Henderson 1920; Abbott 1974); Caribbean Sea: Bermuda; Cuba (Turner 1955); between Margarita island and Araya peninsula (Princz 1986); Bahamas (Redfern 2001); Colombia (Díaz & Puyana 1994); Brazil: Amapá to Rio Grande do Sul (Penna­Neme 1974; Scarabino 1975, 1985, 1994; Caetano & Absalão 2005), Fernando de Noronha (Watson 1879); Uruguay: Rio de la Plata (Henderson 1920; Turner 1955; Scarabino 1973); Argentina: off Buenos Aires Province, Porto Quequen (Carcelles & Parodiz 1938; Turner 1955), gulf of San Matias (Scarabino 1973, 1975). Living from low tide to 71 m (Scarabino 1994), and in unknown condition, down to 95 m (Caetano & Absalão 2005).

Remarks

Polyschides tetraschistus is easily distinguishable from P. portoricensis by the absence of swelling at the anterior third of the shell and by the more thick apical lobes. This species is mentioned as commonly preyed by sea­stars ( Astropecten spp.) from South Brazil, off Uruguay and Buenos Aires province ( Argentina) (Carcelles & Parodiz 1938; Carcelles 1944; Penchaszadeh 1973).

Figures

FIGURES 57 – 73. Genus Episiphon, Entalina, Polyschides and Cadulus. (57) Episiphon didymum, IBUFRJ 14310, 7 mm; (58 – 59) Episiphon sowerbyi, IBUFRJ 14250, 8 mm; (60 – 61) Entalina platamodes, IBUFRJ 13793, 10 mm; (62 – 63) Polyschides portoricensis, IBUFRJ 10576, 7 mm; (64 – 65) Polyschides tetraschistus, (64) Holotype BMNH 1887.2. 9.66, 7 mm, (65) IBUFRJ 14280, 6 mm; (66 – 69) Cadulus parvus, (66) Holotype USNM 314713, 5 mm, (67 – 69) IBUFRJ 9858, 5 mm; (70 – 71) Cadulus eliezeri n. sp., Holotype IBUFRJ 10810, 3 mm; (72 – 73) Cadulus nerta n. sp., Holotype IBUFRJ 14314, 3 mm. Scale bar = 50 m.