Description
The white-edge freshwater whipray has a thin and oval pectoral fin disc slightly wider than long. The anterior margins of the disc converge with a broad angle at the tip of the snout, which is slightly protruding. The eyes are small and immediately followed by much larger spiracles. There is a flap of skin between the nares with a fringed, subtly concave or three-lobed posterior margin. The mouth is gently bow-shaped, with a groove running from the nasal flap around its corners. There are 38–45 upper tooth rows and 37–46 lower tooth rows; the teeth are well-spaced and arranged in a quincunx pattern. Each tooth has a blunt conical crown with a transverse cutting edge; this edge is higher and serrated in males and lower and blunt in females. There is a row of 4–5 papillae across the floor of the mouth: a large inner pair, a smaller outer pair, and sometimes a central one of varying size.
The tail is about 3.5 times as long as the disc and bears two stinging spines on top; behind the spines the tail becomes slender and whip-like, without any fin folds. Two recorded individuals had tail spines 86 and 87 mm (3.4 and 3.4 in) long with 70 and 89 serrations respectively. A band of skin running along the back from between the eyes to the tail base is roughened by small, flattened heart-shaped dermal denticles interspersed with small conical denticles. There are more denticles on the tail behind the spines, and small individuals also have a pearl spine in the center of the disc. The disc is brown above, with mottling in the center and on the tail base, a white spot between the eye and spiracle, and a sharp white band running around its periphery. The underside is completely white, as is the tail behind the spines. This ray grows up to 60 cm (24 in) across and perhaps over 2 m (6.6 ft) long.
Read more about this topic: White-edge Freshwater Whipray
Famous quotes containing the word description:
“It is possible—indeed possible even according to the old conception of logic—to give in advance a description of all ‘true’ logical propositions. Hence there can never be surprises in logic.”
—Ludwig Wittgenstein (1889–1951)
“Do not require a description of the countries towards which you sail. The description does not describe them to you, and to- morrow you arrive there, and know them by inhabiting them.”
—Ralph Waldo Emerson (1803–1882)
“I fancy it must be the quantity of animal food eaten by the English which renders their character insusceptible of civilisation. I suspect it is in their kitchens and not in their churches that their reformation must be worked, and that Missionaries of that description from [France] would avail more than those who should endeavor to tame them by precepts of religion or philosophy.”
—Thomas Jefferson (1743–1826)