Caecum lucidum de Folin, 1867

Raines, Bret K., 2020, A Rosetta Stone for eastern Pacific Caecidae (Gastropoda: Caenogastropoda), Zootaxa 4827 (1), pp. 1-146 : 78-81

Caecum lucidum de Folin, 1867

Figures 57 A–H, 58A–L, 59A–B, 128F

Caecum lucidum de Folin, 1867d: 10 , 2 syntypes MNHN-IM-2000-4595, Panama.

Caecum lucidum — Kisch, 1959a: 36.

Brochina species #5— Lightfoot, 1993b: 77, fig. 23.

Material examined. In addition to the type material the following lots were examined. NHMLAC: LACM 1971 - 83.58 , Los Arcos, Banderas Bay , Jalisco, Mexico, intertidal to 3 m, 6 sh ; LACM 1972 - 17.48 , Jobo Bay , Guanacaste Prov., Costa Rica, 1–8 m, 5 sh . SBMNH: SBMNH 619687 , Punta Coyote, Baja California Sur, Mexico, 20–57 m, 1 sh ; SBMNH 621515 , Punta Jacinto, Guayas, Ecuador, intertidal, 1 sh ; SBMNH 620549 , Cabo Tepoca, Sonora, Mexico, 20–30 m, 4 sh ; SBMNH 621534 , Cabo Tepoca, Sonora, Mexico, 20–30 m, 18 sh ; SBMNH 621364 , Punta la Gringa , Bahia de los Angeles, Baja California [Norte], Mexico, 20–40 m, 25 sh ; SBMNH 621423 , Loreto, Baja California Sur, Mexico, 12 m, 1 sh ; SBMNH 622391 , Puertecitos, Baja California [ Norte ], Mexico, 2–3 m, 1 sh ; SBMNH 452439 , Isla Danzante, NE end, Baja California Sur, Mexico, 60–90 m, 30 sh ; SBMNH 452458 , Roca Acero, Sonora, Mexico, 30–45 m, 10 sh ; SBMNH 452459 , El Tomatal Fish Camp, Baja California [ Norte ], Mexico, intertidal, 2 sh ; SBMNH 452483 , Bahia Carrizal , Colima, Mexico, 0–3 m, 1 sh ; SBMNH 452484 , Isla Chapetona, Sonora, Mexico, 0–2 m, 1 sh ; SBMNH 452540 , Isla Danzante, NE end, Baja California Sur, Mexico, 70–100 m, 30 sh ; SBMNH 452558 , Ensenada San Francisco, Sonora, Mexico, 23–40 m, 12 sh ; SBMNH 452559 , Roca Acero, Sonora, Mexico, 30–45 m, 25 sh ; SBMNH 452560 , Balboa, Panama, Panama, 1 sh ; SBMNH 452561 , Punta Doble, San Carlos Nuevo Guaymas , Sonora, Mexico, 10–25 m, 14 sh ; SBMNH 452562 , Isla Danzante, W of, Baja California Sur, Mexico, 45–55 m, 12 sh ; SBMNH 452563 , Las Cocinas, Sonora, Mexico, 13 m, 15 sh ; SBMNH 619498 , Bahia de los Angeles, Baja California [ Norte ], Mexico, intertidal, 7 sh ; SBMNH 15731 , Isla Carmen, Baja California Sur, Mexico, 3 sh ; SBMNH 619525 , Las Cocinas, Sonora, Mexico, 13 m, 25 sh ; SBMNH 118345 , Empalme, Empalme, Sonora, Mexico, intertidal, 1 sh ; SBMNH 128784 , Bahia de los Angeles, Baja California [ Norte ], Mexico, intertidal, 4 sh ; SBMNH 129974 , Puertecitos, 1.5 mi N [ Playa Curbina ], Baja California [Norte], Mexico, intertidal, 1 sh ; SBMNH 619688 , Isla Ildefonso, Baja California Sur, Mexico, 10–25 m, 1 sh ; SBMNH 118498 , Punta San Felipe, San Felipe , Baja California [Norte], Mexico, intertidal, 1 sh ; SBMNH 619690 , Isla San Jorge [ Bird Island ], Sonora, Mexico, 0–5 m, 1 sh ; SBMNH 119742 , Punta Colorado, Sonora, Mexico, intertidal, 16 sh ; SBMNH 619691 , Punta Colorado, Sonora, Mexico, intertidal, 1 sh ; SBMNH 124391 , Bahia Ballenas , Baja California Sur, Mexico, intertidal, 1 sh ; SBMNH 619692 , La Cruz de Huanacaxtle , Nayarit, Mexico, 17–40 m, 1 sh ; SBMNH 129976 , Puertecitos, 1.5 mi N [ Playa Curbina ], Baja California [Norte], Mexico, intertidal, 1 sh ; SBMNH 619693 , El Submarino, Sonora, Mexico, 11 m, 6 sh ; SBMNH 619700 , Punta San Pedro, Sonora, Mexico, 10–25 m, 25 sh ; SBMNH 619701 , Punta Mareno, Sonora, Mexico, 10–25 m, 2 sh ; SBMNH 128588 , Isla San Martin, S end, Baja California [ Norte ], Mexico, 3–9 m, 1 sh ; SBMNH 619702 , Roca Acero, Sonora, Mexico, 28 m, 15 sh ; SBMNH 118346 , Empalme, Empalme, Sonora, Mexico, intertidal, 1 sh ; SBMNH 128459 , Bahia Salinas , Baja California Sur, Mexico, 16–18 m, 1 sh ; SBMNH 127636 , Bahia San Luis Gonzaga, N entrance, Baja California [ Norte ], Mexico, 5–7 m, 4 sh ; SBMNH 619703 , Bahia San Luis Gonzaga , Baja California [Norte], Mexico, 4–5 m, 3 sh ; SBMNH 127143 , Chacala, Nayarit, Mexico, 3–5 m, 3 sh ; SBMNH 619909 , Punta San Pedro, Sonora, Mexico, 10–25 m, 50 sh ; SBMNH 132339 , Bahia de los Angeles, Baja California [ Norte ], Mexico, 11–31 m, 20 sh ; SBMNH 620168 , Bahia La Choya , Sonora, Mexico, intertidal, 1 sh ; SBMNH 620768 , Isla Partida SW tip, Baja California Sur, Mexico, 10–15 m, 1 sh ; SBMNH 125865 , Panama City, Panama, Panama, 1 sh ; SBMNH 621341 , Punta Buto, Baja California Sur, Mexico, intertidal, 1 sh ; SBMNH 621365 , Playa Venado, Panama, Panama, 25 sh ; SBMNH 621383 , Puerto San Carlos, Bahia Magdalena , Baja California Sur, Mexico, 2–10 m, 6 sh ; SBMNH 621416 , Bahia San Carlos , San Carlos Nuevo Guaymas, Sonora, Mexico, 15–30 m, 20 sh ; SBMNH 621664 , Isla San Pedro Martir, Sonora, Mexico, 120 m, 6 sh ; SBMNH 622361 , Agua de Chale , Baja California [Norte], Mexico, intertidal, 1 sh. JL: Venado, Panama, intertidal, 1 sh ; Nayarit, Mexico, intertidal, 1 sh .

Original diagnosis. “Testa tenui, valde arcuata, conica, vitrea, diaphana; costulis angustis irregularibus, valde sinuosis, longitudinaliter ornata et strigis distantibus, transversim cingulata; inter costulas interstitiis latis, longitudinalibus, minutis strigis ornatis.” de Folin (1867d: 10).

Description. Protoconch unknown. Teleoconch I short, smooth with weak axial growth lines ( Fig. 58A ), transition to teleoconch II marked by change in sculpture ( Fig. 58A ). Teleoconch II about 3 times length of teleoconch I, sculptured with longitudinal dextral striae ( Fig. 58C ), transition to teleoconch III marked by change in sculpture ( Figs. 58A, D ). Teleoconch III sculptured with sinuous longitudinal cords and numerous longitudinal striae ( Fig. 58F ), transition to teleoconch IV marked by incised axial line ( Fig. 58D ). Teleoconch IV sculptured with numerous sinuous, longitudinal lines ( Fig. 58I ), transition to teleoconch V marked by suture ( Fig. 59A ). Teleoconch V with identical characters as previous stage ( Fig. 58I ), transition to teleoconch VI marked by suture ( Fig. 58H ). Teleoconch VI (last growth stage) large for genus [Tol 3.60–3.63 mm], tubular, rather thick, mildly to moderately and regularly arched [Larc: 1.22–1.29 mm; Arc: 0.25–0.28 mm], subcylindrical with slight increase in diameter from posterior to aperture, creamy white, mottled ( Figs. 57 A–B, 58K). Surface glossy, sculptured with numerous, raised, sinuous, longitudinal cords ( Fig. 58J ). Axial sculpture of 16–20 low, rounded ribs begins centrally, rather closely arranged and regularly spaced, except last 3–4 preceding aperture, which are pronounced, widely separated ( Fig. 58K ). Axial interspaces shallow, narrower than ribs, except last 4–5 preceding aperture, which become wider ( Fig. 58K ). Posterior [Dpe: 0.71–0.75 mm] with thick edge, squared shoulder ( Fig. 57C ). Septum hemispherical, recessed ( Fig. 58K ). Mucro low blunt point, not visible in adult stage. Aperture [Da: 0.90–0.99 mm] with 3–4 pronounced axial ribs ( Fig. 58K ). No varix. Lip smooth ( Figs. 57 B–C). Periostracum thin, smooth, yellowish brown ( Fig. 57D ). Operculum thin, light brown; exterior surface with 6–7 concentric rings ( Figs. 57 G–H). Conceptual reconstruction of growth stages shown in Fig. 59A .

Distribution and Habitat. From San Felipe Point, Baja California, Mexico to Paitilla Point, Panama. Intertidal to 120 m. Common on coarse sand substrates.

Remarks. The type material of Caecum lucidum is comprised of two damaged subadult specimens (MNHN-IM-2000-4595, Figs. 57 E–F), which Kisch (1959a) referred to as “ holotype ” and “ paratype ”. However, de Folin never made a distinction between the two specimens, so they must be treated as syntypes. Although damaged, they provide adequate details for identification.

Lightfoot’s (1993b: 77) Brochina species #5 is an example of Caecum lucidum , and her assessment of the species was perfect. Early stage subadults are often misidentified as worn subadult C. subspirale .

Figures

FIGURE 57. Caecum lucidum. A. Profile view (SBMNH 452540). B. Ventral view, adult stage (SBMNH 452540). C. Ventral view, subadult stage (SBMNH 452540). D. Profile view, early subadult stage with periostracum (SBMNH 619525). E–F. Syntypes, MNHN-IM-2000-4595. G. Operculum, exterior surface (SBMNH 452559). H. Operculum, interior surface (SBMNH 452540).

FIGURE 58. Caecum lucidum shells at different growth stages. A. Teleoconchs I to III (SBMNH 452558). B. Surface of teleoconch I (SBMNH 452558). C. Surface of teleoconch II (SBMNH 452558). D. Teleoconchs II to IV (SBMNH 452559). E. Teleoconch IV (SBMNH 452561). F. Surface of teleoconch III (SBMNH 452559). G. Teleoconch V (SBMNH 132339). H. Teleoconchs V to VI (SBMNH 452561). I. Surface of teleoconchs IV to V (SBMNH 452561). J. Surface of teleoconch VI (SBMNH 452540). K. Teleoconch VI (SBMNH 452540).

FIGURE 59. Caecum lucidum. A. Conceptual reconstruction of growth stages. B. Species distribution map.