---
title: Kernel Cowrie (Nucleolaria nucleus)
scientific_name: Nucleolaria nucleus
common_name: Kernel Cowrie
taxon: Cowries
published: 2026-08-29T19:05:36.415Z
updated: 2026-08-29T20:46:21.273Z
tags: Kernel Cowrie, Nucleolaria nucleus, Cowries, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/cowries/kernel-cowrie
---

# Kernel Cowrie (*Nucleolaria nucleus*)

## Quick facts

- **Group:** Cowries (*Cypraeidae*)
- **Size:** up to 3.7 cm
- **Diet:** Herbivore
- **Activity:** Nocturnal
- **Rarity:** Uncommon
- **Habitat:** Reef and rubble, under stones and coral by day
- **Reproduction:** Egg layer, Gonochoric

## How to recognise it

- shell granulose, its surface raised into ridges and grains rather than polished
- ridges run across the shell and continue onto the underside
- mantle carrying very long papillae, far longer than other cowries here
- under four centimeters, squat and rounded

This is the second cowrie on this reef that broke the family's main rule, and it broke it differently.

A cowrie shell is normally a polished object, because the mantle folds up over it and works the surface from the outside as the animal grows. One species here answers that with a coat of fine pustules. This one goes further: the whole shell is granulose, raised into ridges and grains that run across the back and continue right over onto the underside, so nothing about it is smooth anywhere. Held in the hand it feels more like a small piece of coral rock than a shell.

The living animal is stranger still. The mantle carries papillae far longer than anything else in the family here, standing up in a tangle over the shell, and a cowrie in that state is genuinely hard to recognize as a snail at all.

Under four centimeters (1.5 in), squat and rounded, which is what nucleus means: a kernel, a small hard thing.

Between the granular shell and the long papillae it is the least cowrie-looking cowrie in this catalogue, alive or dead, and one of the easiest to name once you know both.

## Also known as

- **English:** Kernel cowry
- **Hebrew:** פי-כושי מגובשש
- **Czech:** zavinutec ořechový
- **Japanese:** イボダカラ, コイボダカラ
- **Russian:** Ципрея-ядрышко

## Scientific synonyms

- *Cypraea gemmosa* Perry, 1811
- *Cypraea lima* Röding, 1798
- *Cypraea madagascariensis* Gmelin, 1791
- *Cypraea nucleus* Linnaeus, 1758
- *Erosaria nucleus* (Linnaeus, 1758)
- *Nucleolaria nucleus gemmosa* (Perry, 1811)
- *Nucleolaria nucleus madagascariensis* (Gmelin, 1791)
- *Nucleolaria nucleus nucleus* (Linnaeus, 1758)
- *Nucleolaria nucleus var. gemmosa* (Perry, 1811)
- *Nucleolaria pseudonucleus* Moretzsohn, 2011
- *Pustularia nucleus* (Linnaeus, 1758)
- *Staphylaea nucleus* (Linnaeus, 1758)
- *Staphylaea nucleus madagascariensis* (Gmelin, 1791)

## Range

Indo-Pacific

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/cowries/kernel-cowrie)*
*Updated: August 29, 2026*