The Tridacna Maxima is also commonly termed as the small giant clam. These species belong to the group of bivalve molluscs. They are most commonly found in the Indonesian Pacific region.

These small giant clams are quite famous in aquarium trade because of their amazing colors. The bright-colored marine creatures are also sometimes imitated at the aquarium as a giant clam.

The Maxima cannot grow themselves longer than a manageable size which is equal to up to 20 centimeters in length. This is equal to 7.9 inches.



Common NameSmall Giant Clam
Scientific NameTridacna Maxima
SynonymsTridacna Acuticostata
Tridacna Elongata
Tridacna elongatissima Bianconi
Tridacna Fossor
Tridacna Troughtoni

Vernacular Names

  • Basa: Philippines
  • Manlet: Philippines
  • Manlot: Philippines
  • Elongate giant clam: UK
  • Elongated clam New: Caledonia
  • Elongated giant clam: Philippines
  • Giant clam: Palau
  • Giant clam: USA
  • Small giant clam: Philippines
  • Katavatu: Fiji
  • Bénitier: French Polynesia
  • Bénitier allongé: France
  • 长砗磲: China
  • Shaza: Kenya
  • Pahua: French Polynesia


The Tridacna Maxima is the most common as well as widespread among this giant-clam. These species are aquacultured from marine trade from so much time. These species were found all over the Indo-pacific and southern Japan.

Whereas in the western side they are usually in East-Africa and in the Red Sea.


Maxima clam or Tridacna maxima was found in 1798. Tridacna Maxima was found all over the Indo-pacific and southern Japan. Tridacna maxima are most commonly seen on the slopes or on the of the reef in shallowly clear water. These species can be found in the depth of 15.24 meter which is around 50 feet.

Fossil Records 

The major scientific extinction that appears in the fossil record is these species exist in shallow-sediments. Therefore, Maxima clam has a little genetic variation as these species are found in the stable environment.

Habitat and Ecology of Tridacna Maxima

The habitat and other similar details of these attractive looking marine species are explained below in detail:


These aquatic creatures can occur at various depths and mostly they are found living on substrates of limestone. They are also found on tops of the coral rubble or living corals.

They can also be seen on sandy bottoms of the sea. When these marine creatures reside at the shallow bottoms of the sea, they fix themselves with the help of a tough structure byssus.

The small giant clam stays on a fixed spot throughout their lifespan.  The bottom of the shell is kept inside the burrow. They also bury themselves among the coral chunks as well as attach themselves to a byssus.

Geo Distribution of Small Giant Clam

These marine clams are found mostly in the Indo-Pacific region. The region of their distribution extends to southern Japan and Great Barrier Reef.

They are also found in the areas of East Africa and the eastern Pacific. This also includes regions such as the Red Sea and Pitcairn Island. The Pitcairn Island is an island which is located near the Capricorn Tropic and it is also volcanic.

These species are also found in abundance in the regions ranging from Hawaiian Islands, Samoa, Tonga as well as other islands included in French Polynesia. However, The population of T. Maxima located in Hong Kong has become extinct now as a result of human interaction.

How T. Maxima Feed?

Researchers claim that these small giant clams satisfy their nutrition requirements through absorbing and filter feeding organic compounds from water. Tridacna uses zooxanthellae to extract the food for them. Even more, they receive most of the nutrition from zooxanthellae.

New research clarifies that Maxima Clams don’t demand to feed in the aquarium.  Rather, There are four different ways in which clams make or extract food for them.

  1. These species have a large number of zooxanthellae that live in their tissue. Also, These algae make their food with plenty of light, containing extra carbon and glucose.
  2. If needed the zooxanthellae can be used for the food by amoeboid-cells.
  3. These species have the ability to absorb nutrition such as Ammonia, phosphate, and nitrate through the water.
  4. Maxima Clams are also known for their filter feeders by straining of various fine particles through their surrounding water.

Clams diet type is Omnivore. They obtain their nutrition through the process of filter-feeding of zooplankton, phytoplankton along with the lighting and zooxanthellae.

Furthermore, the clam of size ranges from 2 inches to 4 inches require feeding of phytoplankton. Once they grow up they still benefit from phytoplankton or otherwise, micro foods are used such as marine snow.

Distinctive Features of Small Giant Clam


The body of Tridacna Maxima is described having bivalves. As a result, these marine creatures have two valves on the mantle. They use gills in order to extract oxygen from the water after siphoning water through their bodies. These species have the following body parts :


The adult small giant clam develops a large shell. This shell is attached to its substrate with the help of its byssus. It is also comprised of long and tough filaments. The functions of these filaments os to enable these marine species in protruding from hole lying next to a fringe.

T. maxima


The mantle is brightly colored in which bright blue, green or brown colors are prominent. When the small giant glam opens up the mantle is exposed. Furthermore, the edges of the shell are obscured by this mantle and it also contains very distinctive and prominent furrows.

These attractive colors appear as a result of the crystalline pigment cells which are present in the mantle of the small giant clam. These crystals are present in order to protect these marine species from harmful effects of intense light.

The purpose of this outer crystalline layer is also to protect the species from abundant light which can harm the process of photosynthesis carried out by them.

Life Cycle of Small Giant Clam

The life cycle of these marine creatures begins as a small size fertilized egg. It develops itself into a free-swimming larva within the next 12 hours. Afterward, this larva develops into a filter feeding stage. Level 3 of the life cycle involves the development of a foot which helps the larva in swimming as well as resting on its substrate.

After a time period of eight to ten days, the larva develops into a juvenile clam. Also, it acquires zooxanthellae at this stage and starts functioning in a symbiotic manner. It takes almost two to three years to become a hermaphrodite.



Fun Facts

Every species has interesting facts associated with them mentioned as following:




Azka Hassan

A software engineering graduate from UET Taxila, I started my carrier as an SQA engineer in the year 2013 and have worked as a Quality Assurance Engineer and Content Creator at various organizations. Currently working as a Content Manager at Tapedaily. Writing research-based content related to Plants, Animals, and various kingdoms are my key interest.

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