Giant Clams and Marine Bivalves Codexery

Tridacna

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Tridacna

Charles J. Sharp · via Wikipedia: Tridacna · CC BY-SA 4.0

Marine bivalve molluscs belonging to the subfamily Tridacninae, known as giant clams, are classified under the genus Tridacna, which consists of large saltwater clams.[1] The shells of these clams are heavy and feature 4 to 6 folds, while the mantle exhibits bright coloration.[1]

Scientific classification

  1. KingdomAnimalia
  2. PhylumMollusca
  3. ClassBivalvia
  4. OrderCardiida
  5. FamilyCardiidae
  6. GenusTridacna

Named by Bruguière, 1797

Sources: Wikipedia taxobox: Tridacna (CC BY-SA 4.0)

Quick Facts

Subfamily
Tridacninae
Shell folds
4 to 6
Cites protection
Appendix II

Facts from the source article.

Key facts and history

Pliny the Elder explained the name because the clams were so large as to require three bites in eating them.[2] By day, the clams spread their mantle so the algae receive sunlight for photosynthesis.[3] Overfishing has caused collapse of natural stocks in many places.[4] Tridacna clams can produce large white non-nacreous pearls.[5]

The genus name Tridacna is derived from the Greek words "tri" (three) and "dacno" (bite).[2] Warm, shallow coral reef waters of the Indo-Pacific region are the natural habitat for Tridacna clams.[1] Once they reach adulthood, these clams are sessile and maintain a symbiotic relationship with photosynthetic algae residing in their mantle tissues.[6] Between 70% and 100% of an adult clam's nutritional needs are met by the symbiotic algae, with the remainder obtained through filter feeding.[3]

CITES Appendix II provides protection for every species within the Tridacna genus.[7] In regions like the Philippines, Tridacna clams are cultivated for the marine aquarium trade, as they are highly sought after for aquaria.[1]

What the cited sources add

Barnett's 2021 article notes that when Tridacna gigas shells first reached Europe, they were revered by collectors and kings and used as baptismal fonts.[8] The same source states that in the English-speaking world, "giant clam" was synonymous with "killer clam" for most of the 19th and 20th centuries.[8] An aquarium trade article reports that about 10% of Tridacna squamosa raised at an Indonesian farm are blue, which is rare in the U.S. market.[9] That farm raises all six species of giant clam commonly sold in the U.S.[9]

A 1939 Natural History article describes a giant Tridacna clam that took the life of a native diver and yielded the world's largest pearl.[10]

References

  1. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: Huelsken, T., Keyse, J., Liggins, L., Penny, S., Treml, E.A., Riginos, C. (2013) A Novel Widespread Cryptic Species and Phylogeographic Patterns within Several (original not read by us) en.wikipedia.org
  2. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: Barnett, "The History, Myth, and Future of the Giant Clam", Atlas Obscura, 2021-07-06 (we also read that source) en.wikipedia.org
  3. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: Klumpp, "Nutritional ecology of the giant clams Tridacna tevoroa and T. derasa from Tonga: influence of light on filter-feeding and photosynthesis", Marine Ecology Progress Series, 1994, p. 147–156 (original not read by us) en.wikipedia.org
  4. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: J.W. Copland and J.S. Lucas, (Eds.), Giant Clams in Asia and the Pacific Vol. 9, Australian Center for International Agricultural Research, Canberra(1988).; ; "Aquarium Invertebrates: A Trip to an Indonesian Coral and Clam Farm", advancedaquarist.com, 7 September 2011 (we also read that source) en.wikipedia.org
  5. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: CIBJO (2007) THE PEARL BOOK:: Natural, Cultured & Imitation Pearls: Terminology & Classification – 5.216. Tridacna gigas (p. 28) (original not read by us) en.wikipedia.org
  6. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: Rosewater, J., The Family Tridacnidae in the Indo-Pacific. Indo-Pacific Mollusca, 1:347-408. 1965; Jantzen, "Photosynthetic performance of giant clams, Tridacna maxima and T. squamosa, Red Sea", Marine Biology, 2008, p. 211–221; (original not read by us) en.wikipedia.org
  7. Wikipedia, "Tridacna" (CC BY-SA 4.0), which cites: "Checklist of CITES species" (original not read by us) en.wikipedia.org
  8. Barnett, "The History, Myth, and Future of the Giant Clam", Atlas Obscura, 2021-07-06. facts only, no text reused. atlasobscura.com
  9. "Aquarium Invertebrates: A Trip to an Indonesian Coral and Clam Farm", advancedaquarist.com, 7 September 2011. facts only, no text reused. advancedaquarist.com
  10. Natural History – PICKS FROM THE PAST: NOVEMBER 1939 – The Pearl of Allah. facts only, no text reused. naturalhistorymag.com

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Tridacna (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

More in Giant Clams and Marine Bivalves

Tridacna croceaTridacna derasaGiant clamMaxima clamTridacna noaeTridacna rosewateriTridacna squamosaTridacna squamosinaArgopecten gibbusArgopecten irradiansArgopecten purpuratusChlamys hastata

Sources

Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

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