La Plata Dolphin
This species of river dolphin is also called the franciscanas, after the Rio de la Plata (River Plate), the wide mouth of several rivers that forms the border between Argentina and Uruguay. As river dolphins, La Plata dolphin can survive perfectly well in the fresh river water, although the tides regularly mix it with salt water. The dolphins do not enter any other rivers, but are found along the Atlantic coast as far north as central Brazil and as far south as the Valdez peninsula in Patagonia, southern Argentina.
Known as "white ghosts" by fisherman, La Plata dolphin feed in murky waters churned up by coastal currents and tides. They have long, slender beaks that curve slightly downward. Without being able to see, they probe the bottom with their snouts, feeding on bottom-dwelling fish. Like all dolphins, franciscanas also orientate themselves using echolocation.
The La Plata dolphin belong to the river dolphin family. In general, river dolphins look unlike oceandwelling dolphins, having smaller fins, many pointed teeth and very long snouts. However, franciscanas may spend their whole lives out at sea, and as a result they look more like oceanic dolphins (although their snout, in relation to body size, is the longest of any dolphin species). The La Plata dolphin's body is greyish on top, which sometimes lightens during winter and with also age - in fact, some older dolphins are predominantly white.
These smooth-swimming dolphins rarely roll or splash, and show little of themselves when they surface. On hot days they have been seen “sunbathing” on the sand in the shallows. If danger threatens, La Plata dolphin will remain motionless near the water’s surface.
Distribution: Mouth of the River Plate and coast of South America.
Habitat: Brackish and salt water.
Size: 1.3 - 1.75 m (4.25 - 5.75 ft); 20 - 61 kg (44 - 134 lb).
Maturity: 3 years.
Breeding: Single young born every two years.
Life span: 16 years.
Status: Data deficient.