Table 1.

Results of shark tooth guillotine experiments. Top number in each box is the percentage of trials in which the tooth punctured the skin or underlying myotomal muscle. Middle number provides the total number of punctures divided by total number of trials, some of which were performed on different areas of the same animal. The bottom of each cell provides the total number of unique animals used for the trials within that treatment. Flaccid refers to hagfish in their natural state and lamprey with skin dissected away and moved to a smaller part of the body. Attached refers to lamprey in their natural state and hagfish in which the skin had been glued to the body. Detached, tight refers to hagfish in which a tube of skin was detached from the body and moved to a larger part of the body to reduce flaccidity, and lamprey in which a tube of skin was dissected away and then returned to the same position.

	Pacific hagfish E. stoutii		Atlantic hagfish M. glutinosa		sea lamprey P. marinus
treatment	% skin punctured	% muscle punctured	% skin punctured	% muscle punctured	% skin punctured	% muscle punctured
flaccid	100 (8/8) n = 6	0 (0/8) n = 6	100 (18/18) n = 6	0 (0/18) n = 6	41 (7/17) n = 7	24 (4/17) n = 7
detached, tight	97 (35/36) n = 6	86 (31/36) n = 6	97 (35/36) n = 6	92 (33/36) n = 6	100 (6/6) n = 4	100 (6/6) n = 6
attached	100 (13/13) n = 6	85 (11/13) n = 6	100 (13/13) n = 6	92 (12/13) n = 6	100 (13/13) n = 7	100 (13/13) n = 7