Yeah I think its the spearer variety since it has been preying on fish and not snails, etc.
I made a trap with an inverted pop bottle and shrimp as bait. Placed it near the conk shell. BTW I have been hearing the tell tale clicking sound for quite some time. I just never knew what it was attributed to.
So after some research I have found that they are one of the smartest animals on the planet. Their eyesight is far superior to humans... they can see colors unseen to us. Their 'punch' moves so fast that it boils the surrounding water and the resulting shockwave will kill its prey if the actual strike misses. They can break glass, cut off thumbs and accelerate at the speed of a .22 caliber bullet.
Hardy, mean and lightning speed with Cyberdyne System Model 101 strength... His name shall be Nemesis.