Read shark researcher Mark Marks' responses on the following shark topics:
Disappearing sharks
Shark evolution
Shark deterrent?
Nonstop swimmers?
Shark posturing
Swimming with the sharks?
Shark diving
Shark education
Shark enemies
Shark reproduction
Great white disposition
Favorite shark
Shark eyes
Shark companions
Bite pressure
Bladderless sharks
Warmblooded killers
Hammerheads
Thresher sharks
Great whites in captivity
Shark protection
Q: On Shark Eyes
I think I have the name right. Why do Pacific white tips have different eyes than other sharks? They are more like a lizard's eyes. Is it true that they are most likely to show up at disaster sites, such as shipwrecks? Also, do they keep company with pilot whales? If so, why?
Thanks,
Wendy Anderson
You may be referring to either the oceanic white tip, Carcharhinus longimanus, or the white-tip reef shark, Triaenodon obesus. Actually, nearly all elasmobranchs have their own distinctive-looking eye. Over millennia, sharks' eyes have evolved depending on its habitat. All sharks have extremely light-sensitive eyes. Some species are more adapted to darkness, like that found in deep waters, whereas others have eyes more suited to, say, hunting in shallow habitats and seeing fine detail. Moreover, all sharks are capable of seeing color, although species that live in the upper layer of the marine environment rely upon sight more than those that occupy the deep regions of the sea and are more sensitive to faint light.
The oceanic white tip is a large, extremely bold and inquisitive species which makes it living as its name implies in primarily open ocean environments. The open ocean can be a difficult place to exist, with prey being at times scarce. These sharks are indeed attracted to plane crash sites and shipwrecks, drawn by the distinctive smells and violent vibrations that come from these scenes. As for the relationship between Pilot whales and C. longimanus, it's true. The sharks will often associate with pods of pilot whales, following the whales while they hunt, and feeding on the remains resulting from the whales attacks on schooling fish.
