Which Creature is the Chilazon?

Ptil Tekhelet's Chilazon

The Ptil Tekhelet candidate for the chilazon is the Murex Trunculus

Radziner Rebbi's Chilazon

The Radziner Rebbi chose the Sepia Officinalis as his candidate for chilazon.

Rabbi Herzog's Chilazon

Rabbi Yitzhak HaLevi Herzog, a Chief Rabbi of Israel, chose Janthina as his candidate for the chilazon.
The mystery of the biblical blue thread, techelet, has fascinated people for thousands of years. The "ptil tekhelet" was a thread of blue fastened to each corner of a Jewish prayer shawl (talit). This website is a personal journey, a kind of ongoing quest, to determine which of the various candidates for the chilazon is the authentic creature needed to make authentic techelet for tzitzit. This site outlines my personal search and is not meant to be an authoritative treatise on techelet or the chilazon. I am not a rabbi, scientist or archaeologist, I am just a regular guy, examining the sources and trying to figure out the truth. I have posted links to relevant sources to help unravel the mystery and explore our understanding of techelet.
Enjoy the journey!