West Indian Top Shell (Cittarium pica) Care Guide
Cittarium pica is a large Caribbean top shell with bold black-and-white markings, a voracious algae grazer suited to larger reef systems.
Compiled by Aquairi from published sources · Published · Updated
Overview
Cittarium pica, the West Indian top shell or magpie shell, is a large marine gastropod with a bold black-and-white shell that can reach up to 137 mm in maximum dimension. It is one of the most economically important invertebrates in the Caribbean and is a heavy algae grazer suited to larger reef aquariums.
Taxonomy
- Family: Tegulidae
- Genus: Cittarium
- Scientific name: Cittarium pica
- Order: Trochida; Superfamily: Trochoidea
Habitat
It occurs through the Caribbean, from the Florida Keys and the Caribbean coasts of Mexico, Costa Rica, Panama, Colombia and Venezuela to the Bahamas, the Greater and Lesser Antilles (south to Barbados and Trinidad and Tobago), and has been reintroduced to Bermuda. It lives on or under rocks on exposed and moderately sheltered shores, in intertidal and shallow subtidal zones at depths of 0 to 7 m.
Tank requirements
- Minimum tank volume: 200 L
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness (dKH): 8-12
- Specific gravity: 1.024-1.026
- Adult shell size: 6-10 cm (up to 137 mm recorded)
- Lifespan: 3-7 years
Diet
Cittarium pica is herbivorous, feeding on a large variety of algae and sometimes on detritus. Its large size and appetite let it process more algae than most reef snails, but it also requires a tank with substantial algal growth to sustain it.
Compatibility
It is a peaceful, reef-safe grazer best matched with larger reef fish given its size. Predatory fish such as triggerfish and pufferfish should be avoided.
Conservation status
The species is heavily harvested for food and is the third most economically important invertebrate in the Caribbean. It has become locally extinct in some areas due to overfishing; it is legally protected in Bermuda, and harvest is regulated in the US Virgin Islands. Wild-collected specimens should be sourced responsibly.
West Indian Top Shell (Cittarium pica): Breeding Notes
Overview
Cittarium pica, the West Indian top shell, is a large Caribbean snail (shell up to 137 mm) of the rocky intertidal and shallow subtidal, found on or under rocks at depths of 0–7 m. It is an herbivore feeding on a wide variety of algae and sometimes detritus, scraping algal growth from rock.
Sexing
The species is dioecious (separate sexes); males release sperm and females release eggs into the water, so sexes are not distinguished externally.
Spawning & Eggs/Larvae
Fertilization is external, with a reproductive season running from June to November. The larvae are lecithotrophic (yolk-feeding) and settle very quickly, after about 3.5–4.5 days — a short pelagic period typical of trochoidean snails.
Common Challenges
Despite the brief larval phase, the planktonic stage is still lost to filtration and predation in reef tanks. Given its conservation pressure, this species is better appreciated for its ecological role than targeted for breeding or harvest.