Tridacna squamosina, or the Red Sea giant clam, exhibits a strong resemblance to T. squamosa but can be distinguished by its asymmetrical shell with deep triangular folds and crowded scutes. Additionally, the mantle is most commonly a subdued brown mottled pattern with a green margin that features prominent “wart-like” protrusions.
T. squamosina is endemic to the Red Sea, with its past and present distribution including the northeastern Gulf of Aqaba, the Sinai coast, and eastern coast of the Red Sea down to Yemen. However, available reports indicate that this species is exceptionally rare. Since it was re-described as a species in 2005, there have been only 30 documented observations of T. squamosina, all within very shallow water habitats, such as reef flats, rocky and sandy rubble flats, and seagrass beds.
Its shallow, nearshore distribution makes it particularly accessible to reef-top gatherers. Combined with the species’ natural rarity, longstanding traditions of giant clam harvest in the Red Sea have likely been the principal cause of the exceptionally low abundance of T. squamosina throughout its range.
| Kingdom | Animalia | Phylum | Mollusca | Class | Bivalvia | Order | Cardiida | Family | Cardiidae | Genus | Tridacna | Species | squamosina |
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A grant project in Guam is setting up giant clam aquaculture in two southern villages, Inalåhan and Malesso. Giant clams are a culturally important species in Guam, where they’re also regulated due to overharvesting. Credit: David Burdick
Fifteen of the 83 species included in the Pacific Islands vulnerability assessment. From left to right: Acanthurus achilles, Caranx melampygus, Tripneustes gratilla, Acanthurus triostegus, Scarus rubroviolaceus, Cephalopholis argus, Octopus cyanea, Lutjanus kasmira, Panulirus penicillatus, Triaenodon obesus, Selar crumenophthalmus, Ctenochaetus strigosus, Naso unicornis, Zebrasoma flavescens, Tridacna maxima. Photo credit: Bruce Mundy.