Grayish
to dark charcoal in color, thresher sharks turn abruptly
white on the belly and may be mottled on the lower half
of the body. Threshers are further identified by the
absene of a keel on the caudal penduncle; by their small,
pointed and broadbased teeth; and by their comparatively
smooth skin. Longtail and pelagic threshers have moderate-size
eyes, and the first dorsal fin is set almost diectly
in the middle of the back and far ahead of the beginning
of the pelvic fins.
