Description
The bowmouth guitarfish is large and heavily built, measuring up to 2.7 m (8.9 ft) in length and weighing 135 kg (300 lb). The head is short, wide, and depressed, with a broadly rounded snout; the anterior portion of the head, including the eyes and large spiracles, is clearly distinct from the body. The nostrils are elongated and oriented nearly crosswise, with well-developed flaps of skin that separate each opening into inflow and outflow apertures. The lower jaw has three protruding lobes that fit into three depressions in the upper jaw. There are around 47 upper tooth rows and 50 lower tooth rows; the teeth are ridged and arranged in winding bands. The five pairs of gill slits are positioned underneath, close to the lateral margins of the head.
The body is deepest in front of the two dorsal fins, which are tall and falcate (sickle-shaped). The first dorsal fin is about a third larger than the second and originates over the pelvic fin origins, whereas the second dorsal is located midway between the first dorsal and the caudal fin. The pectoral fins are broad and triangular, with a deep indentation between their origins and the sides of the head. The pelvic fins are much smaller than the pectoral fins, and the anal fin is absent. The tail is much longer than the body, with a large, crescent-shaped caudal fin; the lower caudal fin lobe is more than half the length of the upper.
There is a thick ridge running along the midline of the back, bearing a band of massive, sharp thorns. More thorn-bearing ridges are found in front of the eyes, from over the eyes to behind the spiracles, and on the "shoulders". The entire dorsal surface has a granular texture from a dense covering of dermal denticles. The coloration is bluish gray above, lightening towards the margins of the head and pectoral fins, and light gray to white below. There are prominent white spots scattered over the body and fins, a white-edged black marking above each pectoral fin, and two dark transverse bands atop the head between the eyes. Younger individuals are more vividly colored than adults, which tend to be more brownish with a fainter pattern and proportionately smaller spots.
Read more about this topic: Bowmouth Guitarfish
Famous quotes containing the word description:
“As they are not seen on their way down the streams, it is thought by fishermen that they never return, but waste away and die, clinging to rocks and stumps of trees for an indefinite period; a tragic feature in the scenery of the river bottoms worthy to be remembered with Shakespeare’s description of the sea-floor.”
—Henry David Thoreau (1817–1862)
“To give an accurate description of what has never occurred is not merely the proper occupation of the historian, but the inalienable privilege of any man of parts and culture.”
—Oscar Wilde (1854–1900)
“Everything to which we concede existence is a posit from the standpoint of a description of the theory-building process, and simultaneously real from the standpoint of the theory that is being built. Nor let us look down on the standpoint of the theory as make-believe; for we can never do better than occupy the standpoint of some theory or other, the best we can muster at the time.”
—Willard Van Orman Quine (b. 1908)