Table 2.

Effect of chela manipulations on which side develops a crusher claw (figure 6a) in American lobsters Homarus americanus [54]. All lobsters were reared on soft food either without any substrata, or with oyster chips for claw stimulation. N, number of individuals.

treatment in instar 4 or 5	phenotypes at instar 8 or 9
	% asymmetrical	% left crushera	N
oyster chips absent
(a) intact claws	14.3	66.7	21
(b) left claw exercised	90.0	83.3	20
(c) left claw stroked	21.7	40.0	23
(d) left claw autotomy	5.0	0.0	20
(e) left claw autotomy and handle animal	0.0	0.0	21
(f) left claw autotomy and right claw exercised	78.9	0.0	19
oyster chips present
(g) intact claws	95.7	54.5	23
(h) right claw dactylotomy	76.5	84.6	17
(i) left claw autotomy	95.8	0.0	24
(j) left claw autotomy and right claw dactylotomy	22.7	40.0	22
(k) left claw autotomy and right closer muscle tenotomy	5.6	100.0a	18
(l) left claw autotomy and right opener muscle tenotomy	17.6	33.3	17

^a % of asymmetrical individuals.