Fire Dragon by Bill J. Harrison

WARNING: You will not hear the sound of the ocean in this sea shell. The Fire Dragon is a cantankerous crustacean responsible for numerous maritime disasters. First discovered in 1949, the Fire Dragon is relentlessly pursued by Dr. Peter Huston and Dr. Beth Sullivan, marine biologists. Also on the trail of the Fire Dragon is a bizarre religious cult, scheming millionaires, and a ruthless assassin. Peter and Beth must discover what evolutionary misstep, or aberrant chemical broth, spawned the Fire Dragon. At every turn they learn more about the astonishing powers of the creature and its ability to bestow longevity or kill in a most spectacular fashion.