The end of parshas Shelach discusses the mitzva of tzitzis. There, the verse says, "...And they shall place upon the tzitzis of each corner a thread dyed with techeles. Gemorah teaches that techeles dye comes from a creature called chilazon. Some identify chilazon as the Murex snail, more specifically, Murex Trunculus. Whether or not this is so, let's learn about this fascinating creature.
The dye made from the secretion of the Murex snail is purplish. But when it is exposed to direct sunlight, the color changes to a shade of blue!
This snail has a broadly conical shell about 4 to 10 cm long. It has a high spire with seven angulated whorls. The shell is formed similar to the shape of a fish. The shell is variable in sculpture and coloring with dark banding, in four varieties. The ribs sometimes develop thickenings or spines and give the shell a rough appearance. The shell is often covered in algae, which camouflages it, making it appear very similar to the seabed.
Interestingly, remnants of many dye-producing factories were found along the Mediterranean coastline, in the territory of Zevulun, with piles of shells from the Murex snail!
