Molluscs · Tegulidae
Tectus fenestratus
Fenestrate top shell
Indo-Pacific top shell sold as "Turban snail" or "Tectus". Its conical, flat-based shell crowned with tubercles grazes algae and encrusting organisms on rock. It is not the trade "Banded trochus", which is a Trochus.
- beginner level
- Adult size
- 1.7–7 cm
This sheet is still being written. Some sections are not filled in yet: they stay hidden while they are empty.
What it needs
Water parameters
- Temperature°C
- SalinitySG
- pH
Day to day
Care and feeding
- LevelBeginner
- FoodHerbivore
Care
Acclimation: none of the sources consulted gives instructions specific to this species. Go slowly, as for any invertebrate, and never use copper treatments (Quality Marine).
Setup: algae-covered rock to graze; in nature it lives on shallow rocky shores.
Watch point: LiveAquaria presents the "Tectus" as a snail that, unlike the Banded trochus, does not right itself when knocked over. If you find it on its back, turn it upright.
Sensitivities: copper (Quality Marine). None of the sources consulted states its tolerance to nitrate or its calcium needs.
Tankmates: Quality Marine rates it "Easy", behaviour "social". None of the sources consulted explicitly calls it "reef safe"; it is a herbivorous grazer, but watch how it behaves around your corals.
Feeding
Herbivore: in the wild it grazes the algae and encrusting organisms that grow on rock and substrate (Quality Marine).
In the aquarium it needs algae to graze. None of the sources consulted gives a supplement specific to this species; for grazing snails in general, Quality Marine recommends dried algae or vegetable pellets when algae run short.
Decor
- Algae-covered rock to graze.
Tank mates
Compatibility
Goes well with
- Peaceful fish and invertebrates.
- Burrowing snails (Nassarius, Cerithium): complementary on the sand.
Avoid
- Copper treatments: lethal to invertebrates.
In detail
Description
Identification: solid, imperforate conical shell, 1.7 to 5 cm (up to 7 cm high), white or grey mottled with green, brown or olive, with a flat white base. The whorls bear a row of tubercles (12 to 20 on the body whorl) and fine oblique wrinkles; the edge of the base is beaded. Common confusion: the "Banded trochus" (Trochus sp. at LiveAquaria and Quality Marine) has maroon bands; according to LiveAquaria, unlike the "Tectus", it rights itself.
In the wild it lives on rocky shores, often in muddy areas, from 0 to 5 m, in the central and western Pacific, Indo-China, Indo-Malaysia, Papua New Guinea, New Caledonia and northern Australia. It is collected locally for food.
Trade: Quality Marine describes it as frequently available (Melanesia, South and East Asia). No data was found on breeding in aquariums.
Characteristics
- Conical shell with a flat white base, 1.7 to 5 cm (up to 7 cm).
- Row of tubercles on each whorl, beaded edge to the base.
- Sold as "Turban snail"; distinct from the Banded trochus (Trochus sp.).
- Grazes algae and encrusting organisms.
- Reportedly does not right itself once on its back (LiveAquaria, about the "Tectus").
- Indo-West Pacific, rocky shores from 0 to 5 m.
Origin
- Indo-West Pacific
Distribution
- Central and western Pacific, Indo-China, Indo-Malaysia, Papua New Guinea, New Caledonia, northern Australia
- Rocky shores, often muddy, 0 to 5 m
Status
Conservation
Not evaluated (NE)
WoRMS
Classification
- Kingdom
- Animalia
- Phylum
- Mollusca
- Class
- Gastropoda
- Order
- Trochida
- Family
- Tegulidae
- Genus
- Tectus
- Species
Where this comes from
Sources
- WoRMSWoRMS — Tectus fenestratus (Gmelin, 1791) (AphiaID 567234) (opens in a new tab) · accessed on November 11, 2026
- WebSeaLifeBase — Tectus fenestratus, Fenestrate top (species summary) (opens in a new tab) · accessed on November 11, 2026
- WebWikipedia (en) — Tectus fenestratus (opens in a new tab) · accessed on November 11, 2026
- WebQuality Marine — Turban Snail (Tectus fenestratus) (description and care info) (opens in a new tab) · accessed on November 11, 2026
- Web
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