Caecum cooki Pizzini & Raines, 2011

Vannozzi, Angelo, 2023, The Caecidae from BIOMAGLO Expedition in the Mayotte-Glorieuses area (Mollusca, Gastropoda), Zoosystema 45 (12), pp. 421-434 : 430-431

Caecum cooki Pizzini & Raines, 2011

( Fig. 3 F-L)

Caecum cooki Pizzini & Raines, 2011: 29 , fig. 4A, B. — Pizzini et al. 2013: 35, fig. 14H-J.

TYPE MATERIAL. — Holotype. French Polynesia • dd;, Tuamotu Islands, Makemo , Arikitamiro Passage ; MNHN-IM-2000-23124 . Paratypes. French Polynesia • 1 dd; same data as for holotype; MNHN-IM-2000-23125 • 1 dd; Society Islands, Tahiti , Tiarei ; fringing reef, shell grit; MNHN-IM-2000-23126 • 4 dd; Society Islands, W Moorea; 17°30’S, 149°46’W; 2-3 m depth; LACM 3131 . Norhtern Mariana Islands • 6 dd; Saipan, Laolao Bay ; 6-9 m depth; BR .

Indonesia • 1 dd; NW side of Lombok, off Ajer & Meno Islets ; 8°22’S, 116°04’E; 5-20 m depth; rubble of steep coral slope; LACM 3130 .

TYPE LOCALITY. — Pacific Ocean, French Polynesia, Tuamotu, Makemo, Arikitamiro Passage.

MATERIAL EXAMINED. — Îles Éparses • 1 dd; Mozambique Channel, Banc du Geyser, BIOMAGLO Stn DW 4789; 12°22’S, 46°25’E; 340-342 m depth; 22.I.2017; MNHN.

Mayotte • 2 dd; Mozambique Channel, S Mayotte, BIOMAGLO Stn DW 4820; 13°05’S, 45°06’E; 295-336 m depth; 27.I.2017; MNHN • 1 dd; Mozambique Channel, S Mayotte, BIOMAGLO Stn DW 4826; 13°05’S, 45°07’E; 489-496 m depth; 27.I.2017; MNHN • 1 dd; Mozambique Channel, W Mayotte, BIOMAGLO Stn DW 4847; 12°41’S, 44°57’E; 738-763 m depth; 30.I.2017; MNHN • 1 dd; Mozambique Channel, NW Mayotte, BIOMAGLO Stn DW 4848; 12°35’S, 44°55’E; 399-402 m depth; 30.I.2017; MNHN • 1 dd; Mozambique Channel, SW Mayotte, BIOMAGLO Stn DW 4853; 13°00’S, 44°56’E; 665-669 m depth; 3.II.2017; MNHN • 2 dd (1 juv); Mozambique Channel, W Mayotte, BIOMAGLO Stn DW 4854; 12°56’S, 44°58’E; 455-465 m depth; 4.II.2017; MNHN • 1 dd; Mozambique Channel, SE Mayotte, BIOMAGLO Stn DW 4869; 12°58’S, 45°16’E; 917-1070 m depth; 07.II.2017; MNHN • 1 dd (growth stage); Mozambique Channel, NE Mayotte, BIOMAGLO Stn DW 4871; 12°44’S, 45°19’E; 462-486 m depth; 8.II.2017; MNHN .

DISTRIBUTION. — Indo-West Pacific, from the eastern coast of Africa ( Kenya and Mayotte) to Maldives, Papua New Guinea, Philippines, New Caledonia and French Polynesia ( Pizzini & Raines 2011; Pizzini et al. 2013; Vannozzi 2017; 2019b; unpublished data).

DIAGNOSIS. — Shell of average size for the genus. Tube smooth, tapering toward the apex. Aperture simple, inclined, preceded by a slight but distinct swelling on the ventral side. Microsculpture of fine longitudinal striae interrupted by growth lines. Macula small, white, heart-shaped. Septum protruding, with a strong, ear-like mucro rotated toward the right side. Juveniles thin, conical and curved, Transition to the adult stage rapid. Length about 2 mm.

REMARKS

This species shows a very wide distribution in the tropical Indo-West Pacific but is never abundant. A small heart-shaped white macula observed in the ventral side of the tube in adult shells is characteristic of this species.

Figures

FIG. 3. — Side and ventral views of Caecum Fleming, 1813 and Mauroceras Vannozzi, 2019 species from BIOMAGLO expedition.: A, C. hyalinum Vannozzi, 2022 from Stn DW4847; B, C. egenum Vannozzi, 2017 from Stn DW4854; C, C. cf. mauritianum de Folin, 1868 from Stn DW4820; D, E, C. mauritianum; D, holotype MNHN-IM-2000-24911; E, paratype MNHN-IM-2000-24912; F-L, C. cooki Pizzini & Raines, 2011; F, specimen from Stn DW4847; G, H, specimens from Stn DW4854 (H, juv.); I-L, specimens from Stn DW4820; M, M. kajiyamai (Habe, 1963) from Stn DW4847; N, M. sandwichense (de Folin, 1881) juv.from Stn DW4854. Scale bar: 1 mm. Images D, E, courtesy of Ph. Maestrati (MNHN).