rbridges.com homepage

A comparison of the Nucleolaria nucleus nucleus (Linnaeus 1758) varieties

The variations of Nucleolaria nucleus nucleus (Linnaeus 1758) are characterized by a dorsum with distinct tuberculations and teeth reaching the margins on both sides. In adult shells, the teeth as well as the dorsal tubercles, are framed with a brownish or purplish color. Recently I had the opportunity to study a very small number of diver collected specimens from the Red Sea off Hurghada, Egypt. Even at first glance, the specimens, though resembling nucleus f. madagascariensis (Gmelin 1791), appeared quite distinct. A review of the Schilders' literature (Schilder & Schilder, 1938-1939; Schilder & Schilder, 1952) revealed that these specimens fit very well the description of nucleus f. sturanyi. Below is plate showing the different variations, and reproductions of the Schilders' descriptions and discussions. Please enjoy studying these comparison specimens, both here and with specimens in your own collection.


Nucleolaria nucleus variation comparison plate

Figure 1. Comparison plate of Nucleolaria nucleus nucleus (Linnaeus 1758) varieties. Columns (from left to right): A) N. nucleus nucleus aff. sturanyi (Sch. & Sch. 1938); B) N. nucleus nucleus f. madagascariensis (Gmelin 1791); C) N. nucleus nucleus (Linnaeus 1758); D) N. nucleus nucleus f. gemmosa (Perry 1811).


Reproduction of Schilders' prodrome discussion of nucleus

Figure 2. Reproduction of Schilders' discussion of nucleus from Schilder & Schilder, 1938-1939.


Reproduction of Schilders' Dautzenburg collection of nucleus

Figure 3. Reproduction of table outlining nucleus variations from Schilder & Schilder, 1952.



Schilder, F. A. & Schilder, M., (1938-1939). Prodrome of a monograph on living Cypraeidae. Proceedings of the Malacological Society of London, 23(3/4): 119−231.

Schilder, F. A. and Schilder, M., (1952). Ph. Dautzenbergs Collection of Cypraeidae. Mémoires Institut Royal des Sciences Naturelles de Belgique (2. ser.), 45: 1–243, plts I–IV.