A great white shark is countershaded, with a dark gray dorsal color and light gray to white underside, making it more difficult for the shark's prey to see it as approaches from above or below in the water column. The particular undulations of the countershading line along its side, where gray meets white, is unique to each shark and helps researchers to identify individual sharks in capture-recapture studies. Guadalupe Island is host to a relatively large population of great white sharks who, through a history of video and photographs showing their countershading lines, are the subject of an ongoing study of shark behaviour, migration and population size.
Species: Great white shark, Carcharodon carcharias
Location: Guadalupe Island (Isla Guadalupe), Baja California, Mexico
Image ID: 19468
Humpback whale, abandoned calf alongside University of Hawaii research boat. This young calf lived only a few days after being abandoned or separated from its mother, and was eventually attacked by tiger sharks.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 05979