A new species of giant clam has been encountered by researchers in the Red Sea and given the name Tridacna costata. The new species is fairly similar to two other well-known species of Red Sea clams and it was therefore first suspect to be a hybrid, but genetic analysis has now deemed it a separate species. Further research carried out in the Red Sea also supports this; there are significant differences in behaviour between the two other species and the newly discovered clam. The two previously known clams spawn during a long period in summer while the new clam spawns during a short period in spring.

Fossil evidence uncovered by researchers has now unveiled something even more interesting; Tridacna costata might be one of the earliest examples of marine overexploitation by humans. Fossil records suggest that the Red Sea Tridacna costata population began do decline rapidly roughly 125,000 years ago. This is the part of our early history when scientists believe modern humans to have first begun to migrate out of Africa. Before this point in history, Tridacna costata accounted for over 80 percent of giant clams in the Red Sea – at least according to current fossil studies. Tridacna costata is a two feet long clam and it is not unreasonable to suspect that it would have been a splendid catch for early humans in search of food. Today, the species is believed to constitute less than one percent of giant clams, but this figure can of course change as the Red Sea becomes even more thoroughly explored.

Tridacna costata is the first new living species of giant clam found in two decades and was accidently discovered by scientists engaged in a Tridacna maxima breeding project. Tridacna maxima, another giant clam, is a much sought after clam in the aquarium trade.

If you want to find out more, the researchers behind the finding have posted their article online in the journal Current Biology on August 28.