A Telemetric Study of the Behavior of Free-Swimming Pacific Angel Sharks, Squatina californica
Nine Pacific angel sharks were tagged near Santa Catalina Island, California, with single-channel or multichannel ultrasonic transmitters incorporating various combinations of sensors to measure swimming speed, depth, light, and temperature. The sharks were tracked for periods of 13 to 25 h and were found to be basically nocturnal, apparently cuing on decreased light intensity averaging 7 lux (range, 1-16) to begin swimming activity which peaked at dusk and midnight. Mean of maximum rate of movement for each shark was 490 m/h. The tagged sharks moved an average of 4 km (range, 2-9) during the trackings and collectively occupied a home area of approximately 150 ha. The sharks swam at depths ranging from 27 to 100 m and readily crossed thermoclines. The number and size of individuals seen at the tagging site changed with season.
Standora, Edward A. and Nelson, Donald R.
"A Telemetric Study of the Behavior of Free-Swimming Pacific Angel Sharks, Squatina californica,"
Bulletin of the Southern California Academy of Sciences:
Available at: http://scholar.oxy.edu/scas/vol76/iss3/4