''Tridacna squamosina'' is a species of the ''

Tridacna ''Tridacna'' is a genus of large saltwater clams, marine bivalve molluscs in the subfamily Tridacninae, the giant clams. They have heavy shells, fluted with 4 to 6 folds. The mantle is brightly coloured. They inhabit shallow waters of coral re ...

'' genus, the giant clams. These animals are

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s belonging to the family

Cardiidae A cockle is an edible marine bivalve mollusc. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae. MolluscaBase eds. (2022). MolluscaBase. Cardiidae Lamarck, 1809. Accessed through: W ...

identified by Sturany 1899. In 2008 Roa-Quiaoit, Kochzius, Jantzen, Zibdah & Richter identified what they believed was a new species of giant clam they called ''Tridacna costata'', however in 2011 Markus Huber and Anita Eschner examined a collection of Rudolf Sturanys specimens, held in the

Natural History Museum, Vienna The Natural History Museum Vienna (german: Naturhistorisches Museum Wien) is a large natural history museum located in Vienna, Austria. It is one of the most important natural history museums worldwide. The NHM Vienna is one of the largest museum ...

, that had remained not properly identified for over 100 years and discovered it was actually ''Tridacna squamosina''. The collection held seven

syntype In biological nomenclature, a syntype is any one of two or more biological types that is listed in a description of a taxon where no holotype was designated. Precise definitions of this and related terms for types have been established as part of ...

s were identified and ''Tridacna squamosina'' was accepted and ''Tridacna costata'' formally synonymized.

Physical characteristics

''Tridacna squamosina'' has is a bivalve mollusk with an elongated. The shell has a few folds compared to other bivalve tridacnas, about 5–7 of the on each shell. The upper shell has somewhat large tooth-like formations projecting form its outer edge. Even when compressed as much as they can be, the ''T. squamosina'' has major spaces between the two halves of its shell, especially in the areas of the tooth-like formations. The mollusk also has a well-sized byssus upon its bottom, quite similar to the ''T. maxima''. Common for other bivalve giant clams, the ''T. squamosina's'' papillose mantle tissue varies a wide array of hues and colors, which range in various patterns. Unlike the ''T. maxima'' or the ''T. squamosa'' however, these formations are much more pronounced in the ''T. squamosina''; although some ''T. maxima'' and ''T. squamosa'' do bear relatively few amounts of papillae. All three's siphon is also ringed with tentacles.

Habitat

The species is distributed across the Tropical areas of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, although when originally formally described it was thought to only exist in the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

where it is actually rare. It inhabits shallow reef areas and various seagrass beds, usually below the surface. ''T. squamosina'' is most concentrated around Oceania and Southeast Asia—with the most being around the Philippines and the Malay Archipelago. ''T. squamosina'' is also found in areas of the Red Sea. In 2005, a student found a giant clam found in the

Gulf of Aqaba The Gulf of Aqaba ( ar, خَلِيجُ ٱلْعَقَبَةِ, Khalīj al-ʿAqabah) or Gulf of Eilat ( he, מפרץ אילת, Mifrátz Eilát) is a large gulf at the northern tip of the Red Sea, east of the Sinai Peninsula and west of the Arabian ...

. An expedition of the 19th century also collected specimens of the same species in the Gulf of Aqaba and of the coast of modern day Yemen. Yet these were taxonomically identified as the ''Tridacna elongata'' with the variation ''squamosina''. The species is also reported to be abundant near the

Bazaruto Archipelago The Bazaruto Archipelago is a group of six islands in Mozambique, near the mainland city of Vilankulo. It comprises the islands of Bazaruto, Benguerra, Magaruque, Banque, Santa Carolina (also known as Paradise Island) and Shell. Nyati Island ...

off the coast of Southern Mozambique. A survey showed that the ''T. squamosina'' makes up only 1% of all tridacnas located in the Red Sea, making the species a rarity in the place they were discovered in. The species also is reported to make up 80% of all tridacnid fossils in the area. This idea leads scientists to believe that the species was heavily hunted nearly 100,000 years ago, when humans had only begun their occupation of the area.

References

{{Taxonbar, from=Q14506281 squamosina Molluscs described in 1899