Common Name

"Band Marbled Cone"

Status

Regarded as a valid species.

Type Locality

Island of Banda, Indonesia

Distribution

Natal to Somalia and to Hawaii and Tuamotu Archipelago (absent from Red Sea, India and Sri Lanka); form vidua in southern and central Philippines; form equestris in Moluccas; form nigrescens in Samoa, Admiralty Is. and Solomon Is.

Maximum Reported Size

132 mm

Description

Moderately small to large, moderately light to heavy. Last whorl conical to ventricosely conical; outline nearly straight, variably convex adapically. Shoulder angulate, moderately to strongly tuberculate. Spire of low to moderate height, consistently low in forms vidua, nigrescens (Pl. 2, Figs. 1-4) and equestris; outline straight to moderately concave. Larval shell of about 2.25 whorls. Postnuclear spire whorls tuberculate. Teleoconch sutural ramps concave in late whorls, with 2-4 weak spiral grooves and additional spiral striae; spiral sculpture often obsolete. Last whorl with weak spiral grooves on basal third to three-fourths Aperture white to bluish white.

Ground colour white to pale violer or pale pink. Last whirl with a blackish brown network of lines, triangular areas and rhomboid blotches clustered in a spiral band on either side of the central area; bands often with a orange to brown background. Base many be tinged with bluish grey. Apex white to light purple; larval whorls light yellow in Hawaiian shells (Perron, 1981a). Postnuclear sutural ramps with blackish brown network of lines and straks. Aperture white, occasionally tinged with violet, pink or yellow; base of aperture may be brown. Aperture white to bluish white.

Periostracum yellow to orange, thin, translucent, smooth.

Dorsum of foot white to cream, heavily mottled with brown, lighter in transition zone from anterior to central part; marginal zone with a relatively broad black band ending in latero-anterior blotch; a black central spot at anterior end and a white fleck beneath the operculum. Sole of foot cream, transversely and longitudinally mottled with brown. Rostrum cream, mottled with brown on dorsal side. Tentacles white to brown, with a dark tip, dorsally mottled with brown. Siphon white, with or without a yellow edge and with a red, brown or black anterior ring as well as a posterior band or half-ring shading from tan to blackish brown (Kohn, 1959a; Kohn & Weaver, 1962; Pearson, unpubl. observ.; Kohn, unpubl. observ.

Shell Morphometry

L	50-150 mm
RW	0.08-1.90 g/mm
RD	0.53-0.66
PMD	0.82-0.94
RSH	0.03-0.10

Habitat & Habits

Shallow subtidal to 90 m (Hawaii: Kohn & Weaver, 1962), mostly encountered in 5-20 m. On coral reef, in reef lagoons; in sand, on weedy sand, rocks, and rubble. Animals active at night (New Caledonia; Tirard, pers. comm., 1989). C. bandanus feeds on gastropods, including congeners (Hawaii; Kohn, 1959b). Egg diameter varies from 299 fm (Palau) to 355 fm (Hawaii) suggesting a minimum pelagic period of 10-15 days (Perron, 1981a,b,c; Perron & Kohn, 1985).

Discussion

C. bandanus is a close relative of from C. marmoreus, and some authors have included it in the latter species. The conchological differences are comparatively slight, consisting of more pronounced spire tubercles and a less regular pattern with 2 distinct dark colour bands in C. bandanus, while the pattern of C. marmoreus is generally uniform and lacks bands. Ecological differences also favour separation on the species level: C. bandanus usually lives in deeper water and often occupies a different microhabitat where both occur in sympatry. In Kwajalein, Marshall Is., C. marmoreus is found on inter-island coral reef and at the east side of the lagoon on sand bottom, while C. bandanus is restricted to rock and rubble bottoms of the ocean-side and the lagoon-side of the west reef; co-occurrence has not been observed (Johnson, 1977; J. & S. Johnson, pers. comm.; Pearson, pers. comm., 1991). Specimens agreeing with the description of C. bandanus-vidua cannot be clearly separated from C. bandanus, by conchological characters. In the western part of the central Philippines, they intergrade with C. bandanus,. Their co- occurrence, with intermediate shells, favours the ranking of C. vidua, as a form of C. bandanus,. Specimens agreeing with the description of C. bandanus-nigrescens show a gradual transition from the typical C. bandanus, pattern to almost black shells. In Western Samoa, 6% of the population have nearly black shells, while in American Samoa, the pattern is like that of C. bandanus, elsewhere. Shell size is similar in American Samoa and Western Samoa. The habitat is very similar in American Samoa and Hawaii (Purtymun, 1977). C. nigrescens, is provisionally considered to be a form, occurring in Samoa, Solomon Is. and Admiralty Is.

References

• Enc. Méth. 1: p. 611, no. 5, (1798, Tab. Enc. pl. 318, fig. 5).