Caecum frugi Vannozzi, 2019

Walter, Angelo Vannozzi & Renda, Walter, 2024, Sampling the depth: New data on the Caecidae (Mollusca, Gastropoda) from northeastern Papua New Guinea, Zoosystema 46 (14), pp. 327-347 : 338-340

Caecum frugi Vannozzi, 2019

( Fig. 6I, J )

Caecum frugi Vannozzi, 2019b: 80 , fig. 2V-Y.

TYPE MATERIAL. — Holotype. Papua New Guinea • sh; Kavieng Lagoon , W entrance to Nissel Passage; KAVIENG 2014 Stn KB02; 2°35.2’S, 150°46.2’E, 6 m depth; MNHN-IM-2000-34763 .

TYPE LOCALITY. — Pacific Ocean, Papua New Guinea, Kavieng Lagoon, 2°35.2’S, 150°46.2’E, 6 m depth.

MATERIAL EXAMINED. — Papua New Guinea • 1 sh; New Ireland; KAVIENG 2014 Stn DW4412; 2°33’S, 150°40’E; 500-600 m depth; 27.VIII.2014; MNHN • 3 sh (juv); New Ireland; KAVIENG 2014 Stn CP4418; 2°27’S, 150°40’E; 335-340 m depth; 28.VIII.2014; MNHN .

DISTRIBUTION. — Known from northeastern PNG ( Vannozzi 2019b).

DIAGNOSIS. — Shell small for the genus, whitish, semitransparent. Protoconch unknown.Teleoconch tubular, arched, almost smooth. Early teleoconch cylindrical, arched, flaring toward the aperture. Adult shell cylindrical, smooth except for several hardly-visible rings in the abapical part. Abapical part slightly swollen, then contracted before the aperture, ending with a fine reflected lip. Septum dome-shaped, on the cutting plane, with a hardly visible mucro just above the cutting plane. Periostracum light brown, dull. Operculum and soft parts unknown. Adult shell length 1.4 mm.

REMARKS

Caecum frugi was described on a single specimen, hence its variability is unknown. Among the examined material, we found a specimen well fitting the holotype, although the annulation in the abapical part is hardly visible ( Fig. 6I ). Three juveniles were found together with C. miliarium n. sp. and, due to the very small tube diameter and the compatible septum shape, likely belong to C. frugi ( Fig. 6J ).

Figures

FIG. 6. — Caecum Fleming, 1813 species from deep-water stations from northeastern PNG: A-D, C. dakuwaqa Pizzini, Raines & Vannozzi, 2013 from Stn DW4470 (C, D: juvenile); E, C. dakuwaqa from Stn DW4463; F, C. cf. succineum from Stn DW4495; G, C. neocaledonicum de Folin, 1868 from Stn DW4470; H, C. neocaledonicum from Stn DW4464; I, C. frugi Vannozzi, 2019 from Stn DW4412; J, C. frugi juv. from Stn CP4418; K, C. neoguineanum Vannozzi, 2019 from Stn DW4495; L, C. sp. from Stn DW4465 MNHN-IM-2022-2399. Scale bars: A-H, K, L, 1 mm; I, J, 0.5 mm.