murex
noun
mu·rex ˈmyu̇r-ˌeks 
plural murices ˈmyu̇r-ə-ˌsēz or murexes
or murexes : any of a genus (Murex of the family Muricidae) of marine gastropod mollusks having a rough and often spiny shell, abounding in tropical seas, and yielding a purple dye
Example Sentences
Recent Examples on the Web As each murex produced only a few drops of precious mucus, the manufacture of commercial quantities of Tyrian purple required the harvesting of vast quantities of these creatures. 
Mark Woolmer, National Geographic, 24 Sep. 2020
Mark Woolmer, National Geographic, 24 Sep. 2020 Word History
Etymology
New Latin, from Latin, mollusk yielding a purple dye; akin to Greek myak-, myax mussel
First Known Use
1589, in the meaning defined above