GLYCYMERIS BIMACULATA

Reaching a maximum length of 13 cm, this species features a lenticular, robust, equivalve and equilateral shell with a rounded shape.

It has:

1. a centrally positioned, convex umbo;
2. the umbones are turned toward each other, classifying this bivalve as orthogyrate. A distinctive trait of this species;
3. a net-like sculpture on the umbones and valves, formed by intersecting concentric and radial striae. Near the umbones, these markings often resemble snowflakes splashes, which is the origin of the species’ name.

Glycymeris bimaculata is mainly found in the Mediterranean Sea, where the largest specimens are recorded. It tends to live in colonies that occupy limited areas of the seabed.

The external shell coloration is reddish-brown with darker concentric bands and pale blotches near the umbones (the characteristic “snowflake splashes” mentioned earlier). The interior is whitish, with brownish shades toward the posterior end.

An interesting fact about this species is that there is a variety known as stellate. It’s a juvenile species recognizable by its dense radial lines and prominent concentric bands across the shell surface.