Pyramid top shell

Geographical Origin and Habitat: Widely distributed throughout the tropical waters of the Indo-Pacific, from East Africa and the Red Sea to the Great Barrier Reef, southern Japan, and French Polynesia. It inhabits shallow water zones, intertidal areas, rocky reefs, and coral reef flats exposed to wave action, typically at depths of 0 to 15 meters.

Taxonomy: Tectus pyramis is a gastropod mollusk belonging to the family Tegulidae (formerly placed in the family Turbinidae). It is commonly known as the pyramid top shell due to the distinct geometric, top-like shape of its thick, conical shell.

Social Behavior: A peaceful, exclusively herbivorous gastropod. It spends its time slowly grazing on live rock, glass, and aquarium decorations, scraping off algae with its radula. It is active both during the day and night and is completely harmless to fish, corals, and other tankmates.

Coloration and Sexual Dimorphism: The shell exhibits a classic conical shape, often greenish-gray, off-white, or olive green, sometimes with dark brown or reddish lines or patterns. The base of the shell is flat and pale. There is no visible external sexual dimorphism; males and females are morphologically identical.

Tank Setup: Can be kept in established marine aquariums of at least 80-100 liters (20-26 gallons) with plenty of stable live rock providing large surface areas for grazing. Ensure rockwork is secure, as these snails are relatively heavy and can knock over loose, unsecured rock pieces or corals.

Diet and Feeding: Feeds almost entirely on microalgae, green hair algae, and diatoms growing on surfaces. In highly clean tanks or setups with low natural algae growth, it is vital to supplement their diet with sheets of dried nori algae or spirulina-based sinking pellets to prevent starvation.

Water Quality: Requires stable reef parameters: salinity/specific gravity of 1.023-1.025, temperature of 24-27°C (75-81°F), pH of 8.1-8.4, and dKH of 8-12. Calcium (400-450 ppm) and magnesium (1300-1350 ppm) levels must be maintained for shell health and growth. Copper and other heavy metals are highly toxic and must be kept at zero.

Compatibility and Tankmates: An excellent reef-safe addition to any clean-up crew. Compatible with peaceful fish, corals, and other non-predatory invertebrates. Avoid housing with snail predators such as triggerfish, puffers, large wrasses, or aggressive hermit crabs that may prey on them or steal their shells.

Aquarium Breeding: Spontaneous reproduction in home aquaria is rare. They are broadcast spawners, releasing gametes into the water column. The resulting planktonic larvae are typically consumed by filter-feeding invertebrates or removed by mechanical filtration, making successful captive breeding uncommon.

Risks and Diseases: The primary risk is the snail falling upside down on its back on flat sand. Tectus pyramis struggles to right itself, and if left unattended, it can perish or become easy prey for opportunistic scavengers like hermit crabs. They are also sensitive to rapid salinity changes during acclimation.