Caecum reversum Carpenter, 1857

Raines, Bret K., 2020, A Rosetta Stone for eastern Pacific Caecidae (Gastropoda: Caenogastropoda), Zootaxa 4827 (1), pp. 1-146 : 62-63

publication ID

https://doi.org/ 10.11646/zootaxa.4827.1.1

publication LSID

lsid:zoobank.org:pub:2CE528C2-DE07-4155-B37D-BE2C342A3901

DOI

https://doi.org/10.5281/zenodo.4457769

persistent identifier

https://treatment.plazi.org/id/03A3DF49-FFDF-FFBF-FF44-FF40FE483F37

treatment provided by

Plazi

scientific name

Caecum reversum Carpenter, 1857
status

 

Caecum reversum Carpenter, 1857 View in CoL

Figures 42 View FIGURE 42 A–F, 43A–H, 44A–B, 126K

Caecum (Fartulum) reversum Carpenter, 1857: 329 View in CoL , holotype NHMUK 1857.6.4.1549, Mazatlan.

Caecum (Fartulum) reversum View in CoL — Carpenter, 1859: 434.

Caecum reversum View in CoL — Carpenter, 1860: 33; Palmer, 1951: 44; Brann, 1966: pl. 37, fig. 377; Pizzini et al. 2007: 4, figs. 2a–d. Fartulum reversum View in CoL — Keen, 1968: 420, fig. 94; Keen, 1971: 398; Kaiser, 1997: 29; Finet et al. 2016: 96.

Material examined. In addition to the type material the following lots were examined. NHMLAC: LACM 1977 About LACM - 144.14 About LACM , Chame Point, Panama Bay, Panama Prov. , Panama, 4 sh ; LACM 1984 About LACM - 45.11 About LACM , between Seymour Island and Baltra Island , Galapagos Islands, 30–46 m, 4 sh ; LACM 1980 About LACM - 65.13 About LACM , Salango Island , Manabi, Ecuador, 6–12 m, 5 sh ; LACM 1934 About LACM - 288.3 About LACM , Tagus Cove, Albemarle Island , Galapagos Islands, 3 sh ; LACM 1933 About LACM - 163.4 About LACM , Albemarle Point, Albemarle Island , Galapagos Islands, 26 m, 2 sh ; LACM 1984 About LACM - 46.10 About LACM , Plazas Island , E of Santa Cruz Island, Galapagos Islands, 21–30 m, 1 sh ; LACM 1934 About LACM - 268.2 About LACM , South Seymour Island , Galapagos Islands, 30 m, 1 sh ; LACM 1934 About LACM - 273.10 About LACM , James Bay, James Island , Galapagos Islands, 44 m, 3 sh . SBMNH: SBMNH 620176 About SBMNH , Barra de Navidad, Barra de Navidad , Jalisco, Mexico, 3–20 m, 2 sh ; SBMNH 619896 About SBMNH , Playa Tamarindo , Guanacaste, Costa Rica, 6–15 m, 3 sh ; SBMNH 452448 About SBMNH , Punta Chame, Panama Prov. , Panama, 36–54 m, 6 sh ; SBMNH 452449 About SBMNH , Balboa, Panama Prov. , Panama, 20 sh ; SBMNH 452450 About SBMNH , Isla Jaltemba , Nayarit, Mexico, 10–25 m, 40 sh ; SBMNH 452530 About SBMNH , Punta Chame, Panama Prov. , Panama, 40 sh ; SBMNH 452535 About SBMNH , Balboa, Panama Prov. , Panama, 15 sh ; SBMNH 452451 About SBMNH , Bahia Audiencia, Manzanillo , Colima, Mexico, 10–25 m, 1 sh ; SBMNH 618585 About SBMNH , Isla Seymour Norte, Isla Seymour Norte , Galapagos, Ecuador, 13–17 m, 5 sh ; SBMNH 620817 About SBMNH , Punta Chame, Panama Prov. , Panama, 12 sh .

Original diagnosis. “ C. ( Fartulum ) t. juniore ‘ C. dextroverso ’ simili, sed septo subconvexo, mucrone reversa, semi-cylindracea, arcuata, aperturam versus convexa; dorsum versus convexa t. adulta?….; operculo?” Carpenter (1857: 329).

Description. Protoconch and teleoconch I unknown. Teleoconch II short, sculptured with weak longitudinal wrinkles ( Fig. 43C View FIGURE 43 ), transition to teleoconch III marked by axial incised line ( Fig. 43A View FIGURE 43 ). Teleoconch III about 2.5 times length of teleoconch II, with identical characters as previous stage ( Fig. 43C View FIGURE 43 ), transition to teleoconch IV marked by axial constriction ( Fig. 43D View FIGURE 43 ). Teleoconch IV sculptured with dense longitudinal striae ( Fig. 43H View FIGURE 43 ), transition to teleoconch V marked by suture ( Fig. 44A View FIGURE 44 ). Teleoconch V with identical characters as previous stage ( Fig. 43H View FIGURE 43 ), transition to teleoconch VI marked by suture ( Fig. 44A View FIGURE 44 ). Teleoconch VI (last growth stage) large for genus [Tol 3.14–3.16 mm], tubular, moderately and regularly arched [Larc: 1.31–1.39 mm; Arc: 0.27–0.28 mm], subcylindrical with slight increase in diameter from posterior to aperture, cream to opaque white ( Figs. 42 View FIGURE 42 A–B). Surface sculptured with dense longitudinal striae ( Fig. 43H View FIGURE 43 ). Posterior [Dpe: 0.45 –0.48 mm] with rather thin edge, squared shoulder ( Figs. 42 View FIGURE 42 C–D). Septum mucronate, recessed ( Figs. 42 View FIGURE 42 C–D). Mucro irregular, blade shaped, position variable, curved, wavy, or folded toward margin ( Figs. 42 View FIGURE 42 C–D). Aperture [Da: 0.65–0.66 mm] thick ( Fig. 42C View FIGURE 42 ). No varix. Lip smooth ( Fig. 42C View FIGURE 42 ). Periostracum thin, smooth, yellowish ( Fig. 42A View FIGURE 42 ). Operculum thin, light brown; exterior surface with 5–6 concentric rings ( Fig. 42F View FIGURE 42 ). Conceptual reconstruction of growth stages shown in Fig. 44A View FIGURE 44 .

Distribution and Habitat. From Navidad Bar, Jalisco, Mexico to Manabi, Ecuador, including the Galapagos Islands. Intertidal to 54 m. Common subtidally on sand and rubble substrates.

Remarks. Although Carpenter (1857) named Caecum reversum based on the mucro of the holotype curving backward, this is not always the case (NHMUK 1857.6.4.1549, Fig. 42E View FIGURE 42 ). The mucro of C. reversum may also be wavy or folded to one side ( Figs. 42 View FIGURE 42 C–D), and the position of the mucro can change with each subsequent growth stage ( Figs. 43 View FIGURE 43 A–B, D–G).

SBMNH

Santa Barbara Museum of Natural History

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Littorinimorpha

Family

Caecidae

Genus

Caecum

Loc

Caecum reversum Carpenter, 1857

Raines, Bret K. 2020
2020
Loc

Caecum reversum

Finet, Y. & Tirado-Sanchez, N. & Chiriboga, A. & Ruiz, D. & Banks, S. 2016: 96
Pizzini, M. & Raines, B. & Nofroni, I. 2007: 4
Kaiser, K. L. 1997: 29
Keen, A. M. 1971: 398
Keen, A. M. 1968: 420
Palmer, K. V. W. 1951: 44
Carpenter, P. P. 1860: 33
1860
Loc

Caecum (Fartulum) reversum

Carpenter, P. P. 1857: 329
1857
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