Envenomation by a cone snail

Venomous cone snails use a highly developed projectile apparatus to deliver their cocktail of toxic conotoxins into their prey. In fish-eating species such as Conus magus (seen below) the cone detects the presence of the fish using chemosensors in its siphon and when close enough extends its proboscis and fires a hollow harpoon-like tooth containing venom into the fish. This immobilizes the fish and enables the cone snail to wind it into its mouth via an attached filament. The fish is then digested.

A cone shell, Conus magus is seen with siphon (upper) and proboscis (lower) extended towards a small fish (gobie). This animated GIF of 11 frames (228 KB) is an excerpt from a 2.2 MB QuickTime movie originally available on the Neurex Corp. homepage (Movie Duration = 12.33 seconds - takes approx. 18 minutes to download via 28.8K modem). You can download the movie here.

The photography was carried out in Dr. Baldomero Olivera's laboratory aquarium in Salt Lake City, Utah.

Permission to display this excerpt kindly given by Neurex Corp., (now Elan Pharmaceuticals), Menlo Park, California. 

Reference :

• A Cone Shell Catches Dinner - including  Quick Time Movie 2.2 Mb  . This movie shows the envenomation of a goldfish by Conus magus, using its proboscis to fire a poison dart (radula) into the small fish. The fish is then eaten ! (From Neurex Corp -Science and Publications - Articles). - [original articles 1 and 2 in Worth magazine].
• Read about The Discovery and Development of SNX-111, the conotoxin from Conus magus that is being trialled for the treatment of chronic pain. [This article is excerpted from Worth Magazine "Pain, Profit and Sweet Relief - the story of a biotech company on the verge". by Craig Canine. Part 1 and Part 2 Worth magazine, USA, March issue, 1997 pp.78-158. See also update by Nick Pachetti, March 1998 and September 1998 ]
• See also ABC News - Science for 16 June 1999 "Cone Snails Compete in Arms Race.

BGL, January 2000