The tail-flip escape behavior is a stereotypical motor pattern of decapod crustaceans in which swift adduction of the tail to the thorax causes the animal to rotate, move vertically into the water column and accelerate rapidly backwards. Previous predictions that a strong jet force is produced during the flip as the tail adducts to the body are not supported by our simultaneous measurements of force production (using a transducer) and the kinematics (using high-speed video) of tail-flipping by the California spiny lobster Panulirus interruptus. Maximum force production occurred when the tail was positioned approximately normal to the body. Resultant force values dropped to approximately 15 % of maximum during the last third of the flip and continued to decline as the tail closed against the body. In addition, maximum acceleration of the body of free-swimming animals occurs when the tail is positioned approximately normal to the body, and acceleration declines steadily to negative values as the tail continues to close. Thus, the tail appears to act largely as a paddle. Full flexion of the tail to the body probably increases the gliding distance by reducing drag and possibly by enhancing fluid circulation around the body.Morphological measurements indicate that Panulirus interruptus grows isometrically. However, measurements of tail-flip force production for individuals with a body mass (M(b)) ranging from 69 to 412 g indicate that translational force scales as M(b)(0.83). This result suggests that force production scales at a rate greater than that predicted by the isometric scaling of muscle cross-sectional area (M(b)(2/3)), which supports previously published data showing that the maximum accelerations of the tail and body of free-swimming animals are size-independent. Torque (τ) scaled as M(b)(1.29), which is similar to the hypothesized scaling relationship of M(b)(4/3). Given that τ is proportional to M(b)(1.29), one would predict rotational acceleration of the body (α) to decrease with increasing size as M(b)(−)(0.37), which agrees with previously published kinematic data showing a decrease in α with increased M(b).

Cheng
J. Y.
,
DeMont
M. E.
(
1996
).
Jet-propelled swimming in scallops: Swimming mechanics and ontogenetic scaling.
Can. J. Zool
74
,
1734
–.
Cromarty
S. I.
,
Cobb
J. S.
,
Kass-Simon
G.
(
1991
).
Behavioral analysis of the escape response in the juvenile lobster Homarus americanus over the molt cycle.
J. Exp. Biol
158
,
565
–.
Daniel
T. L.
,
Meyhöfer
E.
(
1989
).
Size limits in escape locomotion of carridean shrimp.
J. Exp. Biol
143
,
245
–.
Dickinson
M. H.
(
1996
).
Unsteady mechanisms of force generation in aquatic and aerial locomotion.
Am. Zool
36
,
537
–.
Domenici
P.
,
Blake
R. W.
(
1993
).
The effect of size on the kinematics and performance of angelfish (Pterophyllum eimekei).
Can. J. Zool
71
,
2319
–.
Drucker
E. G.
,
Lauder
G. V.
(
1999
).
Locomotor forces on a swimming fish: three-dimensional vortex wake dynamics quantified with digital particle image velocimetry.
J. Exp. Biol
202
,
2393
–.
Edwards
D. H.
,
Fricke
R. A.
,
Barnett
L. D.
,
Yeh
S.-R.
,
Leise
E. M.
(
1994
).
The onset of response habituation during growth of the lateral giant neuron of crayfish.
J. Neurophysiol
72
,
890
–.
Edwards
D. H.
,
Yeh
S.-R.
,
Barnett
L. D.
,
Nagappan
P. R.
(
1994
).
Changes in synaptic integration during the growth of the lateral giant neuron of crayfish.
J. Neurophysiol
72
,
899
–.
Full
R. J.
,
Tu
M. S.
(
1990
).
Mechanics of six-legged runners.
J. Exp. Biol
148
,
129
–.
Gal
J. M.
,
Blake
R. W.
(
1988
).
Biomechanics of frog swimming. I. Estimation of the propulsive force generated by Hymenochirus boettgeri.
J. Exp. Biol
138
,
399
–.
Gal
J. M.
,
Blake
R. W.
(
1988
).
Biomechanics of frog swimming. II. Mechanics of the limb-beat cycle in Hymenochirus boettgeri.
J. Exp. Biol
138
,
413
–.
Heitler
W. J.
,
Fraser
K.
,
Ferrero
E. A.
(
2000
).
Escape behavior in the stomatopod crustacean Squilla mantis and the evolution of the caridoid escape reaction.
J. Exp. Biol
203
,
183
–.
James
R. S.
,
Cole
N. J.
,
Davies
M. L. F.
,
Johnston
I. A.
(
1998
).
Scaling of intrinsic contractile properties and myofibrillar protein composition of fast muscle in the fish Myoxocephalus scorpius L.
J. Exp. Biol
201
,
901
–.
Meyhöfer
E.
,
Daniel
T.
(
1990
).
Dynamic mechanical properties of the extensor muscle cells of the shrimp Pandalus danae: cell design for escape locomotion.
J. Exp. Biol
151
,
435
–.
Nauen
J. C.
,
Shadwick
R. E.
(
1999
).
The scaling of acceleratory aquatic performance: body size and tail-flip performance of the California spiny lobster Panulirus interruptus.
J. Exp. Biol
202
,
3181
–.
Rayner
M. D.
,
Wiersma
C. A. G.
(
1963
).
Functional aspects of the anatomy of the main thoracic and abdominal flexor musculature of the crayfish Procambarus clarkii (Girard).
Am. Zool
4
,
285
–.
Rayner
M. D.
,
Wiersma
C. A. G.
(
1967
).
Mechanisms of the crayfish tail flick.
Nature
213
,
1231
–.
Somero
G. N.
,
Childress
J. J.
(
1990
).
Scaling of ATP-supplying enzymes, myofibrillar proteins and buffering capacity in fish muscle: relationship to locomotory habitat.
J. Exp. Biol
149
,
319
–.
Webb
P. W.
(
1976
).
The effect of size on the fast-start performance of rainbow trout Salmo gairdneri and a consideration of piscivorous predator—prey interactions.
J. Exp. Biol
65
,
157
–.
Webb
P. W.
(
1979
).
Mechanics of escape responses in crayfish (Orconectes virilis).
J. Exp. Biol
79
,
245
–.
Wine
J. J.
(
1984
).
The structural basis of an innate behavior pattern.
J. Exp. Biol
112
,
283
–.
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