Caecum floridanum Stimpson, 1851

Lima, Silvio Felipe Barbosa & Christoffersen, Martin Lindsey, 2016, Redescription and designation of a neotype for Caecumfloridanum (Littorinimorpha, Truncatelloidea, Caecidae) with a characterization of the protoconch and growth stages, ZooKeys 585, pp. 17-31 : 19-23

Taxon classification Animalia Littorinimorpha Caecidae

Caecum floridanum Stimpson, 1851 Figs 1, 2, 3, 4

Caecum floridanum Stimpson 1851: 112 (Recent, Florida).

Caecum irregulare Folin 1867: 47, pl. 3, fig. 6 (Bahia state, northeastern Brazil; syntype MNHN 25729; Recent) - Dall (1892: 298), Abbott (1974: 92, fig. 874), Rios (1975: 40, pl. 11, fig. 142, 1985: 44, pl. 17, fig. 199, 1994: 57, pl. 18, fig. 211, 2009: 98, fig. 237), Diaz and Puyana (1994: 141, pl. XLV, fig. 489), Redfern (2001: 41, pl. 20, fig. 174 a–b) [Fig. 4D, type material].

Caecum phronimum Folin 1867: 44, pl. 3, fig. 4 (Port au Prince, Haiti; syntype MNHN 25728; Recent) - Abbott (1974: 92, fig. 874), Rios (1985: 44, pl. 17, fig. 199, 1994: 57), Diaz and Puyana (1994: 141, pl. XLV, fig. 489), Absalão and Pizzini (2002: pl. 1, fig. 2, pl. 2, Figs 15-16) [Fig. 4E, type material].

Caecum floridanum var. compactum Dall 1892: 298, pl. 20, fig. 9b (Caloosahatchie River, near Fort Thompson, Florida; type USNM 83590; fossil, Pliocene) - new synonym [Fig. 4F, type material].

Caecum cayoense Rehder 1943: 190, pl. 20, fig. 9 (Bonefish Key, Florida Keys; holotype USNM 536045; Recent) - Abbott (1974: 92, fig. 874), Tunnell et al. (2010: 144).

Caecum puntagordanum Weisbord 1962: 165, pl. 14, Figs 13-14 (south flank of Punta Gorda anticline, Venezuela; holotype PRI 26107, paratype, PRI 26108; fossil, Pliocene] - Abbott (1974: 92, fig. 874), Tunnell et al. (2010: 144) [Fig. 4 G–H, type material].

Type material.

NEOTYPE ANSP 407671 (herein designated - Fig. 1), USA, Florida: Venice - collected by Donald R. Moore, June 1963.

Additional material examined.

United States of America: -- off Florida State: [8] ANSP 100196, Bahia Honda Key; [1] ANSP 141044, Dry Tortugas, 1925, 29 m; [13] ANSP 306229, John’s Pass, 1965, 62 m; [1] UF 350743, Palm Beach, 01 April 1979; [1] UF 359106, Crawl Key, 01 August 1978; [1] UF 359111, Cayo Costa, beach drift, 01 April 1992; [11] UF 359112, Palm Beach, beach drift, 01 February 1988; [1] IBUFRJ 1920, collector Tarrasconi, subtidal, 04 February 1999; [5] MZSP 42358, [6] MZSP 91154, collector P.J. Souza, Deerfield Beach, 3 to 5 m, January 1999; Bahamas: [3] UF 359107, Cat Key, beach drift, 01 March 1981; [3] UF 359108, Sampson Cay, beach drift, 01 June 1992; West Indies: -- off Virgin Islands: [1] UF 359109, St. Croix, 19.81 m, 01 January 1993; -- off ABC Islands: -- Aruba Island: [4] IBUFRJ 6500, [11] IBUFRJ 6906, collector F. Verberne; -- off Venezuela: [1] PRI 26107, holotype and [1] PRI 26108, paratype ( Caecum puntagordanum ), Tertiary, Lower Pliocene, Mare Formation, Punta Gorda Anticline; -- off Trinidad and Tobago: [6] UF 359105, Tobago Island, 1.82 to 8.53 m, 01 January 1992; [14] UF 359113, Tobago Island, beach drift, 01 April 1991; Brazil: -- off Amapá State: AMASSEDS, collector R/V 'Columbus Iselin’ - [5] MORG 39.824, April 1997; [8] MORG 43.297, station 4134, 45 to 50 m, March 1997; -- off Pará State: GEOMAR, collector R/V 'Almirante Saldanha’ - [2] MORG 15.815, Cânion do Amazonas, station 2438, 40 m, 1970; [5] MORG 15.902, Rio Pará, 25 m, 1970; [2] MORG 16.517, Foz do Amazonas, station 2438, 40 m, 08 November 1970; AMASSEDS, collector R/V 'Columbus Iselin’, cruise III - [3] IBUFRJ 18306, station 3209, 01°21'N, 48°00'W, 53 m, May 1990; [2] IBUFRJ 18308, station 3210, 01°52'N, 48°16'W, 47 m, 12 May 1990; [1] IBUFRJ 18309, station 3228, 03°25'N, 49°55'W, 74 m, 17 May 1990; [3] IBUFRJ 18310, station 3201, 00°29'N, 48°11'W, 12 m, May 1990; [1] IBUFRJ 18377, station 3210, 01°52.45'N; 48°16'W, 47 m, 05 December 1990; -- off Maranhão State: REVIZEE/Score NORTE, collector Márcia - [15] IBUFRJ 18316, Banco do Tarol, 20 July 1997; -- off Rio Grande do Norte State: collector MORG research group - [dozens] MORG 19.119, [7] MORG 26.453/28.186, Atol das Rocas, February 1977; -- off Paraíba State: [2] MZSP 77776, Formosa beach, Cabedelo, January 1979, collector L.R.L. Simone; [12] UFPB MOLL 3545, [02] MZSP 114729, Cabo Branco Beach, in rhodolith beds, 22 December 2011, collector André, Emerson, Jéssica, Lívia, Rafael and Silvio; -- off Pernambuco State: [4] IBUFRJ 11179, Rata Island, Fernando de Noronha Archipelago, 08 August 1999, collector IBUFRJ research group; [3] MORG 32.949, Fernando de Noronha Archipelago, 40 m, 05 December 1986, collector M. Cabeda; [3] MZSP 32004, Fernando de Noronha Archipelago, 0-6 m, 20 July 1999, collector P.J. Souza and L.R.L. Simone; collector LMUFRPE research group - [3] LMUFRPE, Porto de Galinhas beach, 05 October 1982; [3] LMUFRPE, Suape, 24 May 1982; -- off Alagoas State: [2] MORG 12.494, Rec. da Marinha, 1964, collector Sá Cardoso; -- off Bahia State: [9] IBUFRJ 7408, [2] IBUFRJ 7287, Ribeira, Salvador, 1994, collector L. Trinchão; [3] MORG 41.867, Recôncavo Baiano, 29 April 1997, collector ‘fishing-boat’; [1] MORG 45.602, Boipeba, 45 m, December 2002, collector R/V 'Astro Garoupa’; [3] MORG 45.639, Camamu Bay, 52 m, 11 December 2002, collector R/V 'Astro Garoupa’; [5] MZSP 44883, Coroa Vermelha Reef, Salvador, 13 January 2000, collector E.P. Gonçalves and P.J. Souza; [7] MORG 18.052, Abrolhos Archipelago, 5 m, July 1972, collector L.C. Araújo; collector MORG research group - [23] MORG 20.113, Abrolhos Archipelago, February 1978; [27] MORG 23.836, Abrolhos Archipelago, January 1985; [29] MORG 26.418, I. Guarita, Abrolhos Archipelago, 5 m, February 1987, collector A.S.J.L. Laurino; [1] MZSP 36863, Alcobaça, Parcel Paredes, 2-3 m, 16 January 2000, collector E.P. Gonçalves and P.J.S. Souza; REVIZEE/Score Central, collector R/V ‘Antares’ - [132] IBUFRJ 10134, [4] IBUFRJ 12679, [10] IBUFRJ 12750, station C76, 15°54'22"S, 38°31'09"W, 66 m, 30 April 1996; [9] IBUFRJ 14688, station 2R, 13°38'S, 38°44'W, 55 m, 02 July 2001; [3] IBUFRJ 18307, [7] IBUFRJ 18315, [4] IBUFRJ 18376, [2] IBUFRJ 18378, [1] IBUFRJ 18379, station R4#1, 13°45'S, 38°23'W, 91 m, 23 June 2002; [5] IBUFRJ 18313, station R3#1, 15°49'S; 38°36'W, 83 m, 21 June 2002; local project - [6] MNRJ 14061, 13°29'22"S, 38°48'43"W, vi.2007; [5] MNRJ 14062, 13°28'17"S, 38°48'44"W, August 2007; [2] MNRJ 14069, 13°29'20"S, 38°47'37"W, August 2007; [3] MNRJ 14071, 13°28'17"S, 38°48'44"W, August 2007; [1] MNRJ 14073, 13°29'20"S, 38°47'37"W, August 2007; [1] MNRJ 14076, 13°16'00"S, 38°55'07"W, 12 January 2007; [6] MNRJ 14081, 13°19'51"S, 38°52'51"W, 12 January 2007; [1] MNRJ 14090, 13°28'58"S, 38°49'06"W, August 2007; [3] MNRJ 14092, 13°28'58"S, 38°48'21"W, August 2007; -- off Espírito Santo State: [1] IBUFRJ 8629, Piúma, 1993, collector IBUFRJ research group; GEOMAR XII, collector R/V 'Almirante Câmara’ - [7] IBUFRJ 7289, 20°53'S, 40°12'W, 26 August 1979; REVIZEE/Score Central, collector R/V ‘Antares’ - [2] IBUFRJ 9280, station C63, 19°40'42"S, 38°08'15"W, 61 m, 25 April 1996; [30] IBUFRJ 9421, [2] IBUFRJ 12752, station C65, 18°53'37"S, 39°06'23"W, 50 m, 25 April 1996; [30] IBUFRJ 9817, [31] IBUFRJ 12689, station C62, 20°30'02"S, 37°28'51"W, 96 m, 25 April 1996; [8] IBUFRJ 10841, station VV31, 18°52' S, 39°35'W, 23 m, 28 February 1996; [4] IBUFRJ 11360, station VV22, 20°20'S, 40°15'W, 33 m, 27 February 1996; [4] IBUFRJ 12681, station VV21, 20°38'S, 40°00'W, 56 m, 27 February 1996; [2] IBUFRJ 12687, station VV16; 21°10'S, 40°27'W, 28 m, 26 February 1996; [2] IBUFRJ 14574, station 42R, 20°44'S, 31°49'W, 85 m, 11 July 2001; [10] IBUFRJ 18311, station Y7, 20°50'S, 40°10'W, 75 m, 28 June 2002; [4] IBUFRJ 18314, station VV22, 20°20'S; 40°59'W, 33 m, 27 February 1996; [6] MORG 40.457, station VV31, 18°52'S, 39°35'W, 23 m, 28 February 1996); [5] MORG 41.084, station VV21, 20°38'S, 40°00'W, 56 m, 27 February 1996; [17] MORG 33.637, Trindade and Martim Vaz Archipelago, 75 m, 25 April 1996; [3] MORG 39.124, 18°53'S, 39°06'W, 50 m, 25 April 1996; -- off Rio de Janeiro State: [2] MZSP 63394, Rio das Ostras, September 1971, collector MZSP research group; GEOMAR XII, collector R/V 'Almirante Câmara’ - [2] IBUFRJ 7288, 22°05'S, 40°17'W, 29 August 1979.

Original description.

"Shell much arcuated, somewhat thick, white, shining; with about thirty-two sharp, elevated ribs, much narrower than their interspaces. Aperture slightly oblique, not contracted. In some specimens there is a broad rib just above the aperture. Long..075; lat..02. poll. Hab. Florida." ( Stimpson 1851: 112).

Diagnosis.

Teleoconch with strong, wide, low, rounded, closely arranged axial ribs, except last three to four preceding the aperture, which are larger and more widely separated.

Redescription

(shell - neotype). Teleoconch IV (last growth stage) small (Tol 3.85 mm), tubular, rather thick, moderately and regularly arched (Larc 1 mm; Arc 0.30 mm), with slight increase in caliber from apical region to aperture, opaque-white to cream–white with brownish markings (Fig. 1 A–B). Surface sculptured with longitudinal striae, faint to well-defined longitudinal threads (Fig. 1D) and 26 prominent, wide, low, rounded, closely arranged and regularly spaced axial ribs (Fig. 1 A–B), except last three preceding aperture, which are larger and more widely separated (Fig. 1E). Striae and threads cross ribs and interspaces (Fig. 1D); threads producing a very slightly beaded effect on ribs (Fig. 1D). Axial interspaces very narrow and shallow, except last two to three preceding aperture, which become wider and deeper (Fig. 1E). Apical region circular (Dpe: 0.57 mm) (Fig. 1C). Septum slightly convex, deeply recessive (Fig. 1C). Mucro finger-shaped, conical, moderately slender (Lm: 0.12 mm; Wm: 0.15 mm), positioned on dorsal margin, straight (Fig. 1C). Aperture circular (Da 0.75 mm), prominent varix around (Fig. 1 A–B, E). Operculum yellowish-brown, horny; outer surface concave, with nucleus subcentral, about eight slight coil (Fig. 1F); inner surface convex, smooth (Fig. 1G).

Characterization.

Protoconch to teleoconch IV. Protoconch paucispiral (about 1.5 whorls), planispiral, smooth; suture deep, grooved; transition to teleoconch I abrupt, marked by slight axial edge (Figs 2 A–B, 4A). Teleoconch I short, sculptured with 9 to 15 wide, very weak, slightly wavy, closely arranged axial riblets and very fine, slight longitudinal striae (Figs 2 A–B, 4A); transition to teleoconch II not observed. Teleoconch II sculptured with 9 to 15 faintly demarcated, well-spaced axial riblets and very weak longitudinal threads and striae (Figs 2 C–E, 4A); transition to teleoconch III not clear or marked by very slight axial strangulation/suture (Fig. 2 F–G). Teleoconch III to IV sculptured with wide, rounded, low, closely arranged axial ribs, longitudinal striae and threads that increase in prominence with the progression of stages (Figs 2 C–E, 3 A–C). Teleoconch III with about 18 axial ribs (Fig. 2 C–E); transition to teleoconch IV not clear (Figs 2E, C) or marked by very slight axial strangulation to pronounced increase in diameter (Figs 2 C–D, 3 A–B). Teleoconch IV small (Tol 2.90-4.25 mm, M 3.53 mm, N 50), arched (Larc 0.85-1.50 mm, M 1.11 mm, N 50; Arc 0.20-0.40 mm, M 0.28 mm, N 50), apical region circular (Dpe 0.37-0.57 mm, M 0.45 mm, N 50), mucro finger-shaped to triangular, conical (Lm 0.07-0.25 mm, M 0.15 mm, N 49; Wm 0.07-0.20 mm, M 0.13 mm, N 50), aperture circular (Da 0.50-0.75 mm, M 0.58 mm, N 50), sculptured with 22 to 33 axial ribs, wider in comparison to previous stages (Figs 2 C–E, 3 A–F, 4A), last three to four usually larger and more separated (Figs 1E, 3 D–F, 4A, D, F). Figure 4A shows the reconstruction of the growth stages.

Type locality.

Florida (Venice), United States (here established).

Geographic distribution.

North Carolina to Florida ( Dall 1892, Rehder 1943, Olsson and Harbison 1953, Abbott 1974, Gomes and Absalão 1996); Texas ( Tunnell et al. 2010); Mexico ( Vokes and Vokes 1983, Lightfoot 1992); Bahamas ( Kisch 1959, Redfern 2001); Cuba ( Espinosa et al. 1995); Puerto Rico ( Rosenberg 2009); Haiti ( Fo lin 1867); Virgin Islands and Saint Martin ( Kisch 1959); Trinidad and Tobago Archipelago ( Lightfoot 1992); ABC Islands ( Jong and Coomans 1988, Gomes and Absalão 1996); Costa Rica ( Sevilla et al. 2003); Panama ( Olsson and McGinty 1958, Sevilla et al. 2003); Colombia ( Diaz and Puyana 1994, Bandel 1996); Venezuela ( Weisbord 1962, Rios 2009); Guiana ( Princz 1977); Surinam ( Rosenberg 2009); Brazil: Amapá, Pará, Maranhão, Ceará, Rio Grande do Norte, Paraíba (presente study), Pernambuco, Alagoas, Bahia, Espírito Santo ( Folin 1867, Dall 1892, Kisch 1959, Leal 1991, Gomes and Absalão 1996, Rios 2009), Rio de Janeiro (present study).