Molluscs · Cardiidae
Tridacna mbalavuana
Tevoro clam
A rare South-West Pacific giant clam known only from Fiji, Tonga and New Caledonia, between 3 and 35 m. It numbers only about 2,100 adults in severely fragmented populations. Endangered on the IUCN Red List.
- intermediate level
- CITES Appendix II
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Day to day
Care and feeding
- LevelIntermediate
Care
No source consulted describes keeping this species in an aquarium: the advice below is what is published for traded giant clams and still needs confirming for it. Acclimation: invertebrates cope badly with even small changes in water chemistry, and clams are sensitive to salinity changes. Acclimate it slowly, by floating and then drip, and never rush the process. It must then get used to the light: a clam under 5 cm has a thinner mantle and is more sensitive to very intense lighting. Start it on the bottom, on a small rock or in a dish of coarse substrate, then move it up gradually, as you would a newly added coral.
Setup: it is a rare, threatened species living deeper than traded giant clams; no source consulted mentions aquarium farming or describes its light needs.
Tankmates: it is a peaceful animal that harms nothing, but in an aquarium anemones, triggerfish and puffers may attack it, and a wandering anemone may sting it. Inspect it before adding it, and quarantine it if you can, to spot parasitic Pyramidellidae snails: they are white, conical, a few millimetres long, and feed on the clam on its shell and foot until it weakens or dies. Remove them by hand (a toothpick will do), checking day after day; the wrasses Halichoeres melanurus and Halichoeres chrysus eat them.
Health signs and sensitivities: the mantle edge carries hundreds of simple eyes; the clam partly closes when the light dims, a shadow passes or an object moves, which is a normal reflex. A mantle that no longer opens fully for several days, on the other hand, should make you look for parasites. Like all invertebrates, it does not tolerate copper treatments. It builds its shell from calcium carbonate, so it draws on the tank's calcium and alkalinity.
Water: no source consulted gives values for this species. For traded giant clams, LiveAquaria gives 22 to 25.5 °C, a specific gravity of 1.023 to 1.025, pH 8.1 to 8.4, 380 to 450 mg/L calcium, 1280 to 1350 mg/L magnesium and an alkalinity of 8 to 11 dKH.
Feeding
No source consulted describes this species' own diet; what follows applies to giant clams in general.
A clam lives mainly on its zooxanthellae, microscopic algae housed in its mantle: in the giant clam they cover 65 to 70% of its needs. It also filters the water continuously and absorbs dissolved matter through its skin.
Tank mates
Compatibility
Goes well with
- Halichoeres melanurus and Halichoeres chrysus: these wrasses eat parasitic Pyramidellidae snails
- Corals and peaceful fish of a brightly lit reef tank: the clam harms no other organism
Avoid
- Anemones: they may move next to the clam, sting it or eat it
- Triggerfish and puffers: possible predators in the aquarium
- Copper-based treatments
In detail
Description
Names: "tevoro clam" or "devil clam" in English, Teufelsmuschel in German; it was also described as Tridacna tevoroa, now a synonym.
In the wild: the IUCN records it from Fiji, Tonga and New Caledonia, 3 to 35 m; SeaLifeBase adds Australia and gives a depth of 20 to 30 m, deeper than most giant clams. No source consulted gives its size.
Status: Endangered (EN) on the IUCN Red List (2024 assessment), declining population; the IUCN lists fishing and aquaculture among the threats. CITES Appendix II and EU Annex B.
Characteristics
- Known only from Fiji, Tonga and New Caledonia.
- Lives deeper than most giant clams (down to 35 m).
- About 2,100 adults in severely fragmented populations.
- Synonym: Tridacna tevoroa.
- Endangered (IUCN 2024); CITES Appendix II, EU Annex B.
Origin
- South-West Pacific
Distribution
- Fiji, Tonga, New Caledonia (IUCN); Australia according to SeaLifeBase
- 3 to 35 m according to the IUCN, 20 to 30 m according to SeaLifeBase
Status
Conservation
CITES Appendix II
EU Annex B
checked on November 11, 2026 · Source: Species+ (opens in a new tab)
WoRMS
Classification
- Kingdom
- Animalia
- Phylum
- Mollusca
- Class
- Bivalvia
- Order
- Cardiida
- Family
- Cardiidae
- Genus
- Tridacna
- Species
Where this comes from
Sources
- WoRMSWoRMS — Tridacna mbalavuana Ladd, 1934 (AphiaID 466759) (opens in a new tab) · accessed on November 11, 2026
- IUCNIUCN Red List — Tridacna mbalavuana: EN (assessed 21 April 2024) (opens in a new tab) · accessed on November 11, 2026
- CITESSpecies+ — Tridacna mbalavuana (CITES Appendix II, EU Annex B; listed with Tridacnidae spp. since 1985) (opens in a new tab) · accessed on November 11, 2026
- WebSeaLifeBase — Tridacna mbalavuana (species summary: size, depth, distribution, biology) (opens in a new tab) · accessed on November 11, 2026
Related species
Other molluscs
Crocus clam
Tridacna crocea