Herbivorous Cetacea are also found in the Amazon; they are called by the Brazilians, Peixe boi, or cow-fish, and by the Indians, Juarouá.
It has not yet been ascertained, whether the cow-fish of the Amazon is the same as the Manatus of the West Indies and the coasts of Guiana, or a distinct species. All the accounts of the Manatus Americanus mention it as being twelve or fifteen feet long on the average, and sometimes reaching twenty. Those of the Amazon appear to average seven or eight feet only; of five or six specimens I have myself seen, none have exceeded this; Lieutenant Smyth saw one on the Upper Uaycali, of the same size; and Condamine describes the one he saw as not being larger.
The inhabitants of the Amazon give accounts of three kinds, which they seem to consider distinct, one smaller, and one larger than the common kind, and differing also in the shape of the tail and fins, and in the colour.
The West Indian species is always described as having external nails on the edge of the fin, or fore-arm. This I never observed in the Amazon species; though in cutting the edge of the fin to take out the bones entire, I must have noticed them, had they been at all so prominent as usually described; neither does Lieutenant Smyth mention them, though he could hardly have overlooked so singular an external character.
I am therefore inclined to think that the Amazon possesses one or two distinct species. Having carefully prepared a skin and skeleton of a fine male (which, with the rest of my collections, was lost on the voyage home), I did not describe it so minutely as I otherwise should have done, but have some notes, referring to male and female specimens, which I will now give:—
- Manatus of the Amazon.
- Peixe boi, of the Portuguese.
- Vaca marina, of the Spaniards.
- Juarouá, of the Indians’ Lingoa Geral.
Dimensions of full-grown male and female specimens from the Rio Negro and Amazon.
| FT. | IN. | |
|---|---|---|
| Total length of male and female | 7 | 0 |
| Snout to the base of the fins | 1 | 6 |
| Snout to the penis in the male | 2 | 9½ |
| Snout to the testicles in the male | 4 | 1 |
| Snout to the vagina in the female | 4 | 1 |
| Snout to the anus | 4 | 7 |
| Snout to the root of the tail | 5 | 3 |
| Circumference at the fins | 3 | 8 |
| Circumference in middle of body | 5 | 4 |
| Circumference at the anus | 4 | 9½ |
| Circumference at the root of the tail | 2 | 6 |
| Breadth of the tail | 1 | 9 |
| Length of the fins | 1 | 2 |
| Opening for exsertion of penis, in length | 0 | 2 |
| Teeth, M. 6–6/6–6 |
The mammæ of the female, one close to the base of each fin behind. The muzzle is blunt, fleshy, and covered with numerous stiff bristles; the nostrils are on the upper part of it, and lunate. The lips, thick, fleshy, and bristly, and the tongue rough. The skin is lead-colour, with a few pinkish-white marblings on the belly; others have the whole of the neck and fore-part of the body beneath cream-colour, and another spot of the same colour on the underside of the tail. The skin is entirely smooth, resembling India-rubber in appearance, and there are short hairs scattered over it, about an inch apart; it is an inch thick on the back, and a quarter of an inch on the belly; beneath it, is a layer of fat, of an inch or more in thickness, enveloping every part of the body, and furnishing from five to ten gallons of oil.
The intestines are very voluminous. The lungs are two feet long, and six or seven inches wide, very cellular, and when blown up, much resemble a Macintosh air-belt. The ribs are each nearly semicircular, arching back from the spine, so as to form a ridge or keel inside, and on the back there is a great depth of flesh. The bone is excessively hard and heavy, and can scarcely be broken. The dung resembles that of a horse.