mature shell, 15 mm
young shell, 4.1 mm
Pyramidella dolabrata (Linnaeus, 1758)
|Maximum size: 26 mm shell
length (Severns, 2000).
of this species are glossy-white with spiral brown bands.
Young shells have folds inside the outer lip that are not visible in
mature shells. They also vary considerably in the angle of coiling. The
animal is cream with opaque-white flecks.
of Pyramidella dolabrata
are moderately rare in beach drift. It's a
nocturnal sand-dweller that is occasionally found in sand samples from Halimeda kanaloana beds taken at
depths of around 10-20 m (33-66 ft). McNae and Kalk (1958) record is as living with the acorn worm Ptychodera flava in Mozambique.
Maui, Oahu and Kauai: circumtropical.
Taxonomic notes: This species may also be listed in Severns, 2011, Quirk & Wolfe, 1974, Morris, 1974 and Tinker, 1958 as Pyramidella terebellum O. F. Muller, 1774. There's
a chance that the variable angle of coiling in young shells
may indicate the presence of two species (see photos showing the extremes). However, it's difficult to draw a clean line between the two using the
available sample. So, we're leaving them together pending further work. (Note 1) It's mis-labelled as Pyramidella sulcata in Kay & Schoenberg-Dole, 1991.
CP: Black Rock, Maui; April 15, 2005(?).
Observations and comments:
1: It's my impression that broader
juvenile shells occur mostly in deeper sand samples while slenderer
shells occur mostly in beach drift. Whether this is due to genetic or environmental factors is unknown.