Common name: Millet Cowrie

Scientific name: Naria miliaris (Gmelin, 1791)

General Information

The Millet Cowrie, scientifically known as Naria miliaris, is a small and fascinating marine gastropod belonging to the family Cypraeidae. Renowned for its smooth, glossy shell adorned with a pattern of tiny, millet-like spots, this species is a favorite among shell collectors and marine enthusiasts. Its shell coloration ranges from creamy beige to light brown, often with a subtle iridescence that adds to its charm.

In the wild, the Millet Cowrie is found in shallow tropical and subtropical waters, often hiding under rocks or within coral crevices during the day. It is primarily nocturnal, venturing out at night to feed. While not as commonly kept in aquariums as some other marine species, it can be an intriguing addition to a reef tank, particularly for hobbyists interested in marine invertebrates.

Details

Estimated price
Affordable
Recommended minimum volume
50 liter (13 gallons)
Salinity
S.G. 1.023 to 1.025
Temperature
24 to 26 °C (75 to 79 °F)
Acidity
pH 8 to 8.5
Average size
4 cm (1½″)
Care level
Moderate to easy Moderate care; sensitive to water quality
Diet
Herbivore Feeds on algae and biofilm; supplement with nori or algae wafers
Reefsafe
Yes
Aggression
Peaceful
Captive bred
No

Taxonomy

  1. Kingdom
    Animals
    Animalia
  2. Phylum
    Mollusks
    Mollusca
  3. Class
    Gastropods
    Gastropoda
  4. Order
    Snails
    Littorinimorpha
  5. Family
    Cowries
    Cypraeidae
  6. Genus
    Cowries
    Naria Gray, 1837
  7. Species
    Millet Cowrie
    Naria miliaris (Gmelin, 1791)
  8. Synonyms
    Cypraea brookei Rous, 1905
    Cypraea differens Schilder, 1927
    Cypraea diversa Kenyon, 1902
    Cypraea effosa Schilder, 1937
    Cypraea erosa inocellata Gray, 1825
    Cypraea gabrielana Gatliff, 1929
    Cypraea gabrieli Gatliff, 1916
    Cypraea inocellata Gray, 1825
    Cypraea magistra Melvill, 1888
    Cypraea metavona Iredale, 1935
    Cypraea miliaris Gmelin, 1791
    Cypraea miliaris brevis M.Smith, 1913
    Cypraea miliaris brookei Rous, 1905
    Cypraea miliaris diversa Kenyon, 1902
    Cypraea miliaris gabrielana Gatliff, 1929
    Cypraea miliaris gabrieli Gatliff, 1916
    Cypraea miliaris magistra Melvill, 1888
    Erosaria differens F.A.Schilder, 1927
    Erosaria metavona Iredale, 1935
    Erosaria miliaris (Gmelin, 1791)
  9. Source: GBIF | Global Biodiversity Information Facility

Care

The Millet Cowrie is relatively hardy and can adapt well to life in a marine aquarium, provided its specific needs are met. It thrives in a stable environment with plenty of live rock, which offers hiding spots and grazing surfaces. This species is sensitive to poor water quality, so maintaining pristine conditions is crucial. Regular water changes and efficient filtration are essential to its health.

As a nocturnal species, the Millet Cowrie may remain hidden during the day, emerging at night to forage. Providing a tank with subdued lighting or areas of shade can help mimic its natural habitat and encourage natural behaviors. It is generally peaceful and can coexist with other reef-safe invertebrates and fish.

Diet and Feeding

In the wild, the Millet Cowrie is an herbivore, feeding primarily on algae and biofilm that it scrapes off rocks and other surfaces. In captivity, it can be sustained on a diet of naturally occurring algae in the tank, supplemented with dried seaweed (nori) or algae wafers. Encouraging the growth of microalgae on live rock can also provide a consistent food source.

Feed the Millet Cowrie sparingly, as overfeeding can lead to water quality issues. Observing its grazing activity is a good indicator of its dietary needs. If the tank lacks sufficient algae, supplementation becomes necessary to prevent starvation.

Behavior and Compatibility

The Millet Cowrie is a peaceful and non-aggressive species, making it suitable for community reef tanks. It poses no threat to corals, fish, or other invertebrates, making it an excellent choice for aquarists seeking a reef-safe addition. However, care should be taken when housing it with predatory species, such as certain wrasses or crabs, which may view the cowrie as a potential meal.

This species is primarily nocturnal, spending most of the day hiding and becoming active at night. Its behavior is generally unobtrusive, and it contributes to the tank's ecosystem by grazing on algae, helping to keep surfaces clean.

Health and Common Issues

The Millet Cowrie is relatively hardy but can be susceptible to poor water quality and sudden changes in tank conditions. Maintaining stable parameters, including temperature, salinity, and pH, is essential to its health. Avoid exposing it to copper-based medications, as these are toxic to invertebrates.

When selecting a Millet Cowrie, look for individuals with intact, glossy shells and active behavior. Avoid specimens with damaged shells or signs of lethargy, as these may indicate underlying health issues.

Habitat

The natural habitat of the Millet Cowrie includes shallow coral reefs, rocky substrates, and lagoon environments in the Indo-Pacific region. It is commonly found in areas with abundant algae growth, which serves as its primary food source. Replicating these conditions in captivity, with live rock and stable water parameters, will help ensure its well-being.