Meeting Abstract

P2.170  Tuesday, Jan. 5  Synchrony of pectoral fin locomotion and eye movement in shiner perch (Cymatogaster aggregata) MANDECKI, Joanna L.*; REID, Duncan; DOMENICI, Paolo; University of Chicago; University of Washington; CNR-IAMC jmandecki@uchicago.edu

Fishes must simultaneously employ multiple functional systems in order to navigate, locomote, and feed in an aquatic environment. We examined the integration of locomotor and sensory systems in shiner perch (Cymatogaster aggregata). The shiner perch is a labriform swimmer that generates sporadic eye movements (around 250-550 deg/s) while scanning the water for passing plankton. We investigated the synchrony of these saccades with the cycling of the pectoral fins, hypothesizing that eye movements tend to occur during relatively “undisturbed” moments of the fin cycle, i.e. the refractory period and the transition between abduction and adduction. Data were collected using high-speed video of fish swimming in a flume at a flow speed of 10 cm/s, and analysis was performed with circular statistics. The results indicate that eye movements show a non-uniform distribution throughout the swimming cycle, with most events occurring during the abduction phase. Nevertheless, the relatively high angular deviation suggests a loose synchronization, most likely due to a behavioral mechanism rather than a physiological one (i.e. with strict phase locking). One potential advantage of this synchronization is that it would allow the fish to perform a saccade, process the visual input in relation to the presence of prey, and make a decision about whether to initiate a motor response prior to adduction, the phase during which maneuvering is commonly initiated. We also found that the oscillatory rhythm of the pectoral fins remains relatively constant, independent of the eye movement event. If the fish’s swimming motion was adjusting in order to be in synch with the saccade, amplitude or frequency of the fin cycle would be expected to vary. Our results therefore suggest that the fish synchronize saccades to the fin beat rather than the reverse.