Everyone agrees, though, that all the species closely resemble one another. These sharks have a staring yellow eye and a mouthful of the wickedest-looking teeth in sharkdom. They are grayish brown above, lighter below, and often have a series of irregular dark spots on the flanks. They have a pointed, slightly upturned snout, and teeth that are always erect and decidedly "fanglike." The fins are heavy and fleshy, often tipped with black on the posterior margins. The first dorsal is situated fairly far back, and is close to the second dorsal, which is almost as large as the first. The base of the tail is stocky. They reach a maximum length of about ten feet in the Atlantic, but larger ones have been reported in other locations. In some places they are considered harmless, while in others they are considered very dangerous. In American waters, Carcharias taurus is considered to be unaggressive and fairly easy to catch, and so it is often used as an aquarium specimen -- where its snaggle-toothed face makes it a popular shark for viewing and photography.