
Source: Wikimedia Commons
Tridacna noae
Reaching 28 cm in shell length. It is told from T. maxima by the scattered teardrop-shaped, white-rimmed spots on its mantle, where that species has linear markings. Long confused with it, this clam was resurrected as distinct in 2014.
Tridacna noae is a giant clam of the Western Pacific. Roding described it in 1798, but it was long treated as the same species as T. maxima until work published in 2014 re-established it as distinct. It had also been described under other names, such as Tridacna ningaloo, which WoRMS now treats as synonyms. Zooxanthellae live in its mantle, and the diagnostic character is a scatter of teardrop-shaped spots with white margins, in contrast to the linear markings of T. maxima. It is smaller than that species but comparable in how it behaves in an aquarium. It attaches to rock by byssal threads and, as a shallow-water species, needs strong lighting. Because its taxonomy was settled only recently, it is still confused with T. maxima and T. crocea in the trade. The IUCN assessed it as Least Concern in 2024, and as a member of the Tridacnidae it is covered by the blanket CITES Appendix II listing.
Source: Wikipedia (CC BY-SA 4.0)
The Noah's Giant Clam grows to Shell length to 28cm.
SeaLifeBase gives its depth range as 1-15 m and a maximum shell length of 28 cm.
The ideal temperature for the Noah's Giant Clam is 24〜27℃.
Origin
Subtropical Western Pacific, at depths of 1-15 m
Size
Shell length to 28cm
Temperature
24〜27℃
Sources: SeaLifeBase (Tridacna noae) / LiveAquaria (Tridacnidae care data) / AlgaeBarn: Water Parameters 101
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Tridacna noae (Röding, 1798)
Synonyms: Tridachnes noae Röding, 1798, Tridacna ningaloo Penny & Willan, 2014, Tridacna troughtoni Iredale, 1927
Authority databases: WoRMS
Nomenclature follows global taxonomic authority databases.
Sources: CITES Appendix II (Tridacnidae spp. listed as a family) / IUCN Red List 2025-2 (assessed 2024, via SeaLifeBase)
Regulations may change. Always verify the latest information with the relevant authorities.
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Mainly photosynthesis by the zooxanthellae in its mantle; small specimens also filter-feed on phytoplankton.
A shallow-water species from 1-15 m that needs strong lighting. LiveAquaria lists high lighting for close relatives such as T. maxima, and this species is treated the same way.
It attaches to rock by byssal threads, so set it on live rock or a flat piece of coral rock. Give moderate randomised flow and choose a spot where no strong jet hits the mantle.
Water 24-27C, specific gravity 1.023-1.025 (33-35 ppt), KH 8-12, calcium 400-450 ppm, magnesium 1280-1350 ppm. Shell growth consumes calcium heavily, so dose and test for it consistently.
Most of its nutrition comes from photosynthesis by the zooxanthellae in its mantle. Adults need little feeding, but specimens under about 5 cm rely more on filter feeding and benefit from added phytoplankton.
It is often confused with T. maxima and T. crocea in the trade; the teardrop mantle spots identify it. The IUCN lists it as Least Concern, but as a member of the Tridacnidae it falls under the blanket CITES Appendix II listing and trade requires permits. A mantle that will not open, retracted edges, or no response to light all signal trouble. Severing the byssus is usually fatal, so never force a clam off the rock it has attached to. Check at night for parasitic pyramidellid snails around the shell gape and remove them.
Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.
The ideal temperature for Noah's Giant Clam is 24〜27℃. Avoid sudden temperature changes and maintain a stable environment.
Noah's Giant Clam typically reaches Shell length to 28cm as an adult. Size may vary depending on care conditions and individual genetics.
Noah's Giant Clam feeds on: Mainly photosynthesis by the zooxanthellae in its mantle; small specimens also filter-feed on phytoplankton.. Aim for a balanced diet with appropriate feeding frequency.
The price of Noah's Giant Clam varies significantly depending on variety, size, and individual quality. Check our market price page for the latest pricing information.
Last updated: September 16, 2026