The body and tail push against the water, generating forward thrust.
The muscle activation and strain patterns that underlie
body bending and thrust generation have been described
for a number of species and show considerable variation.
This suggests that muscle function may also vary among
species. This variation must be due in large part to the
complex interactions between muscle mechanical
properties, fish body form, swimming mode, swimming
speed and phylogenetic relationships. Recent work in
several laboratories has been directed at studying patterns
of muscle power output in vitro under simulated swimming
conditions. This work suggests that the way that fish
generate muscle power and convert it into thrust through
the body and caudal fin does indeed vary. However, despite
the differences, several features appear to be common to
virtually all species studied and suggest where future effort
should be directed if muscle function in swimming fish is
to be better understood.