Maxima clam

Tridacna maxima

The maxima clam , also known as the small giant clam, is a species of bivalve mollusc found throughout the Indo-Pacific region. They are much sought after in the aquarium trade, as their often striking coloration mimics that of the true giant clam; however, the ''maximas'' maintain a manageable size, with the shells of large specimens typically not exceeding 20 centimetres in length.
Tridacna maxima Took advice from this link for the ID:
https://meilin5giantclam.wordpress.com/2016/10/20/is-this-i-think-it-is-no-wait-what/
The eyes so close in a line indicate T. maxima. Fall,Geotagged,Malaysia,Maxima clam,Tridacna maxima

Appearance

Bivalves have two valves on the mantle. These siphon water through the body to extract oxygen from the water using the gills and to feed on algae. The ''maxima'' is less than one-third the size of the true giant clam .
Giant Clam Seen in Abu Galawa Kebir.
Hamata, Egypt.          Egypt,Fall,Geotagged,Giant clam,Maxima clam,Tridacna (Tridacna) gigas,Tridacna maxima

Distribution

The small giant clam has the widest range of all giant clam species. It is found in the oceans surrounding east Africa, India, China, Australia, Southeast Asia, the Red Sea and the islands of the Pacific.

Found living on the surface of reefs or sand, or partly embedded in coral, the small giant clam occupies well-lit areas, due to its symbiotic relationship with photosynthetic algae, which require sunlight for energy production.
Maxima clam - Tridacna maxima Tentative ID, could also be a Boring Clam Fall,Geotagged,Malaysia,Maxima clam,Tridacna maxima

Behavior

A sessile mollusc, the small giant clam attaches itself to rocks or dead coral and siphons water through its body, filtering it for phytoplankton, as well as extracting oxygen with its gills. However, it does not need to filter-feed as much as other clams since it obtains most of the nutrients it requires from tiny photosynthetic algae known as zooxanthellae.

Beginning life as a tiny fertilised egg, the small giant clam hatches within 12 hours, becoming a free-swimming larva. This larva then develops into another, more developed, larva which is capable of filter-feeding. At the third larval stage, a foot develops, allowing the larva to alternately swim and rest on the substrate. After eight to ten days, the larva metamorphoses into a juvenile clam, at which point it can acquire zooxanthellae and function symbiotically. The juvenile matures into a male clam after two or three years, becoming a hermaphrodite when larger . Reproduction is stimulated by the lunar cycle, the time of day, and the presence of other eggs and sperm in the water. Hermaphroditic clams release their sperm first followed later by their eggs, thereby avoiding self-fertilisation.

Habitat

The small giant clam has the widest range of all giant clam species. It is found in the oceans surrounding east Africa, India, China, Australia, Southeast Asia, the Red Sea and the islands of the Pacific.

Found living on the surface of reefs or sand, or partly embedded in coral, the small giant clam occupies well-lit areas, due to its symbiotic relationship with photosynthetic algae, which require sunlight for energy production.

References:

Some text fragments are auto parsed from Wikipedia.

Status: Unknown
EX EW CR EN VU NT LC
Taxonomy
KingdomAnimalia
DivisionMollusca
ClassBivalvia
OrderCardiida
FamilyCardiidae
GenusTridacna
SpeciesT. maxima
Photographed in
Egypt
Malaysia