La Plata Dolphin Size report
The La Plata Dolphin (Pontoporia blainvillei) is the only dolphin species that live in saltwater. Its greatest physical features are a particularly long, narrow beak and a large head. These rare aquatic animals are mainly found in the coastal Atlantic waters of southeastern South America, including Argentina, Brazil, and Uruguay.
La Plata dolphins are known as the "white ghost" because of their pale skin. They like to live in groups in the deep waters of the river, rarely near the shore and boats, but they often swim to shallow waters near the shore, chasing fish and shrimps for predation at dawn and dusk. These dolphins prefer to live at distances of up to 55 km from the coast, at water depths of 6-35 meters.
The population of La Plata dolphins is growing at 2% per annum, which is not enough to compensate for the annual loss of 500-800. Mortality is largely attributable to human activities. Although this species is not directly exploited in Latin America, La Plata dolphins are caught as bycatch in gill nets, where they may drown or be eaten by sharks. In the following post, let's find out more interesting facts about these endangered dolphins.
La Plata Dolphin Size And Appearance
The La Plata dolphin has a tan back and lighter sides and belly. Their color grows lighter as they age, so light that they have been called “white ghosts” by fishermen. They have a stocky, rounded body that narrows to a wide neck with unfused vertebrae that allow this species neck mobility. The fumarole is a unique crescent shape, and the dorsal fin is small and triangular with a rounded tip. Juveniles have eyebrows and seven hairs on the upper jaw, which disappear with age. The front teeth of the La Plata dolphin are longer than the back teeth. Some teeth were twisted in crowns, with approximately 50 to 63 teeth in each jaw, with lengths ranging from 6.2 to 9.1 mm.
Average Size of La Plata Dolphin
The La Plata dolphin is the only dolphin species that live in saltwater and is one of the smallest. The male adult dolphins are 1.2-1.6 meters long, and the females are 1.3-1.8 meters long; their average weight is 36-50 kg. Calves are born between October and January, following a 10.5-month gestation period. They measure about 70 cm long and weigh 7-9 kg at birth. The lifespan of La Plata dolphins reaches about 20 years.
This species breeds and mates in January-February or October-January, when prey is more plentiful. Young dolphins reach sexual maturity in two or three years. Male La Plata dolphins reach sexual maturity between 2-3 years of age or when they grow to 1.3 m, while females reach maturity at 2-5 years when they grow to 1.4 m. The size and age of maturity vary by region, especially between northern and southern regions.
| Quick Facts | |
|---|---|
| Scientific name | Pontoporia blainvillei |
| Average Length | male: 1.2-1.6 m; female: 1.3-1.8 m |
| Average Weight | 36-50 kg |
| Maturity | male: 2-3 years; female: 2-5 years |
| Lifespan | 20 years |
Living Habits And Habitats
La Plata dolphins are shy and usually consist of 2-15 dolphins in small groups, but as many as 40 dolphins gather together to hunt together. They work together to prey on bottom-dwelling fish schools, use echolocation to find prey in the waters of their habitat, and can descend to more than 25 meters underwater. La Plata dolphins are aquatic mammals that breathe with their lungs. Every time they take a breath, the top of their head and the breathing hole first surface, and then their back and low triangular dorsal fin are exposed. The long dive time can reach 200 seconds. Every minute or two, they must come out of the water for a breath. When the weather is hot and heavy rain is coming, they will frequently come out of the water and rise and fall together.
La Plata dolphins generally inhabit coastal waters of oceans and estuaries, usually in warm and turbid waters with countercurrents. On the Argentine coast, they occupy waters close to shore in spring and summer and farther from shore in winter. In other areas, species cannot move seasonally from the coast, likely because water temperatures remain fairly constant. Preferred habitats are affected by tides.
Diet
La Plata dolphins are carnivores that feed exclusively on fish and marine invertebrates. Due to the small oral organs and digestive tract of La Plata dolphins, they are limited in the size of prey they can ingest. Generally, they mainly eat whole freshwater fish with a body length of less than 6.5 cm and many aquatic plants and insects. The diet of this coastal species varies widely. Surprisingly, La Plata dolphins have poor eyesight and rely on their ultrasonic signals to detect food and devour it.
Conlcusion
The La Plata dolphin is a member of the river dolphin group and the only one that lives in the ocean and saltwater estuaries rather than inhabiting exclusively freshwater systems. Commercialized areas that create agricultural runoffs and industrialized zones can affect the health of the La Plata dolphin, especially the contributions of wastewater and pollution, which can lead to habitat degradation and poisoned food, among other concerns. While it is difficult to accurately estimate the population of Rio de la Plata puffer dolphins, they are considered the most threatened calves in the southwestern Atlantic.
