Maneuverability of four species of coral-reef fish that differ in body andpectoral-fin morphology

Maneuverability was measured during feeding and agonistic interactions in f our sympatric species of coral-reef fish differing in body and pectoral-Fin morphology: foureye butterflyfish, Chaetodon capistratus (deep body. low a spect ratio (AR) fins), beaugregory damselfish, Stegastes leucostictus (med ium-depth body, low AR fins), ocean surgeonfish, Acanthurus bahanieusis (me dium-depth body, high AR fins), and bluehead wrasse, Thalassoma bifasciatum (slender body, high AR fins). Damselfish turned faster, using median- and paired-fin propulsion, than either surgeonfish or wrasse, but their perform ance did not differ from that of butterflyfish during maneuvering behaviour s common to all species. Each of these pairs had similar pectoral-fin morph ology but exhibited an intermediate body morphology. This suggests that pec toral-fin morphology was more important in determining performance within m aneuvers, and therefore butterflyfish and damselfish were superior maneuver ers to surgeonfish or wrasse. To turn faster, fish shifted from median- and paired-fin propulsion to body and caudal-fin propulsion: however, turning radii were unaffected. Pectoral-fin morphology also determined the use of m aneuvering behaviours within gaits that are used by fish to fractionate the ir locomotor-performance range, In general, morphological differences among species were correlated more often with behavioral differences than with l ocomotor performance. Fish differing in body and fin morphology express dif ferent gaits, and within these gaits, they express different behaviours; ho wever. overall performance may converge.