Description
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 short furrows at the corners. There are 21–25 and 20–27 tooth rows in the upper and lower jaws respectively. The knife-like teeth each have a strongly angled main cusp flanked by up to three smaller cusplets on either side; the lateral cusplets are absent in young sharks. There are five pairs of gill slits, with the fifth pair the longest.
The lateral line runs along each side of body in a conspicuous furrow. The pectoral fins are short, while the pelvic fins are relatively large with long bases. The first dorsal fin is small and originates at or behind the level of the pelvic fin origins; the second dorsal fin is similar to the first and positioned close behind. The anal fin is absent, and the stout caudal peduncle lacks depressions at the caudal fin origins. The caudal fin has a longer upper lobe without a notch in the trailing margin, and an indistinct lower lobe. The skin has a dense, uniform covering of non-overlapping dermal denticles measuring up to 0.4 cm (0.16 in) across, which are never fused together as in the bramble shark. Each denticle is thorn-like, with strong ridges running down the central spine and radiating out over the star-shaped base. The denticles beneath the snout are very fine in adults. The prickly shark is plain brown or gray, often with a purplish tint, and has black trailing margins on the fins. The underside is paler, most obviously on the snout and around the mouth. It may reach a length of 4.0 m (13.1 ft). The maximum recorded weight is 266 kg (590 lb) for a 3.1 m (10 ft) long female.
Read more about this topic: Prickly Shark
Famous quotes containing the word description:
“An intentional object is given by a word or a phrase which gives a description under which.”
—Gertrude Elizabeth Margaret Anscombe (b. 1919)
“Whose are the truly labored sentences? From the weak and flimsy periods of the politician and literary man, we are glad to turn even to the description of work, the simple record of the month’s labor in the farmer’s almanac, to restore our tone and spirits.”
—Henry David Thoreau (1817–1862)
“The next Augustan age will dawn on the other side of the Atlantic. There will, perhaps, be a Thucydides at Boston, a Xenophon at New York, and, in time, a Virgil at Mexico, and a Newton at Peru. At last, some curious traveller from Lima will visit England and give a description of the ruins of St Paul’s, like the editions of Balbec and Palmyra.”
—Horace Walpole (1717–1797)