Search results
Results From The WOW.Com Content Network
Dorsal fin diagram with landmarks labeled. Fins allow the sharks to be able to guide and lift themselves. Most sharks have eight fins: a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin. Pectoral fins are stiff, which enables downward movement, lift, and guidance.
The prickly shark has a flabby and cylindrical body, with the adults markedly bulkier than juveniles, and a short, moderately flattened head. The nostrils are placed far apart and preceded by small flaps of skin. The spiracles are tiny and positioned well behind the eyes, which lack nictitating membranes. The mouth forms a broad arch, with very ...
Carpet sharks have two dorsal fins, without spines, and a small mouth that is forward of the eyes. Many have barbels and small gill slits, with the fifth slit overlapping the fourth. The upper lobe of the caudal fin tends to be mostly in line with the body, while the lower lobe is poorly developed.
The first dorsal fin is small and somewhat sickle-shaped, with a pointed apex and a short, free, rear tip; its origin lies over the free rear tips of the pectoral fins. The second dorsal fin is relatively large, though still less than half the height of the first. No ridge is seen between the dorsal fins. The pectoral fins are short and tapered ...
The first dorsal fin is large, high, stiff and angular or somewhat rounded. The second dorsal and anal fins are minute. The caudal peduncle has a few or less distinct keels. The teeth are gigantic. The fifth gill opening is in front of the pectoral fin and spiracles are sometimes absent.
The sandbar shark is one of the largest coastal sharks in the world, and is closely related to the dusky shark, the bignose shark, and the bull shark. Its dorsal fin is triangular and very high, and it has very long pectoral fins. Sandbar sharks usually have heavy-set bodies and rounded snouts that are shorter than the average shark's snout.
The fins are distinctively large and rounded at the tips. The pectoral fins of adults are broad and falcate (sickle-shaped). The dorsal fins have nearly vertical trailing margins, with the first originating over the pectoral fin rear tips. The second dorsal fin is about three-quarters as high as the first.
The two dorsal fins are of nearly equal size and placed far back on the body, with the first originating over the latter third of the pelvic fin bases and the second over the latter half of the anal fin base. The pectoral and pelvic fins are broad and rounded; the males have stout claspers. The pelvic and anal fins are about as large as the ...