silver dollar

1. A spineless hemispherical cactus (Astrophytum asterias) native to Texas and northern Mexico, having large yellow flowers.
2. See honesty (sense 4).

Myleus pacu

FAMILY

Characidae

TAXONOMY

Myleus pacu Jardine and Schomburgk, 1841, Guyana.

OTHER COMMON NAMES

English: Pacu, pacupeba; German: Brauner Mühlsteinsalmler; Portuguese: Pacu dente; Creole: Koumarou-nwé, pakou.

PHYSICAL CHARACTERISTICS

Maximum length 8 in (20 cm). This species is deep-bodied with a small head and a broad mottled reddish brown body. A row of scutes occurs along the edge of the belly, and the body scales are small. Two rows of teeth are found on the upper jaw; the front row is incisor-like, the back row contains molars.

DISTRIBUTION

South America in Guyana, French Guiana, Brazil, Suriname, and Bolivia.

HABITAT

Inhabits streams and main stems of rivers.

BEHAVIOR

Gregarious and rarely aggressive. During the rainy season, large groups migrate to small creeks to reproduce.

FEEDING ECOLOGY AND DIET

Although their powerful dentition can cause serious bites, silver dollars are herbivores that feed primarily on aquatic plants (often of the family Podostemaceae). Occasionally, they also consume seeds and fruits, which they crush with their large molars. Predators include larger carnivorous fishes, caimans,

otters, river dolphins, and a wide variety of fish-eating birds. Some fish are also taken by humans.

REPRODUCTIVE BIOLOGY

Reproduce by external fertilization. Females and males swim through the water together; females broadcast eggs into the water column, where they are fertilized by males. No parental care.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

Common aquarium fishes throughout the world. Also provide an important food source for many communities living near streams inhabited by pacus.

The noun has 2 meanings:

Meaning #1: a dollar made of silver
  Synonym: cartwheel

Meaning #2: southeastern European plant cultivated for its fragrant purplish flowers and round flat papery silver-white seedpods that are used for indoor decoration
  Synonyms: honesty, money plant, satin flower, satinpod, Lunaria annua