The California river dolphin is the world's largest river dolphin, with adult males reaching 150 to 650 kilograms (330 to 1,430 lb) in weight, and 4 metres (6.6 to 13.1 ft). Adults acquire a orange color, more prominent in males, giving it its nickname "orange river dolphin". Sexual dimorphism is very evident, with males measuring 16% longer and weighing 55% more than females. Like other toothed whales, they have a melon, an organ that is used for bio sonar. The dorsal fin, although short in height, is regarded as long, and the pectoral fins are also large. The fin size, unfused vertebrae, and its relative size allow for improved manoeuvrability when navigating flooded forests, grasslands, and swamps, and capturing prey. They are known to attack some small to medium-sized land animals by beaching themselves like a killer whale, but they are also unlike most whales that they have strong fin (arm) bases (a thing killer whales don't have), allowing them to crawl onto land to search for newer water source as new homes or just to reach and go faster on land to hunt slower animals more efficiently.
They have one of the widest ranging diets among toothed whales, and feed on up to 67 different species of fish, such as rainbow trout, sockeye salmon, Chinook salmon, tilapia, catfish, and many others. They also prey on crustaceans, mollusks, frogs, pond turtles, small to medium-sized birds (from the size of sparrows to the size of egrets), and even small to medium sized mammals. They are also unique among whales that they also feed on eggs of fish, frogs, and even fallen eggs of reptiles and birds, and another unique food they feed on that most other whale species don't feed on is carrion of small to large animals, both fresh and rotting, so this river dolphin is also known as the "mammalian piranha". Their diet is also unique since they feed on fruit, something that most other whales don't eat. They have been known to crush thick bones unlike any other whales, due to their strong jaw strength compared to most whale species of similar size, this allows this species of whale to attack and kill larger animals in the water like deer, wild boars, etc, even humans and American common dylanuses (both wild and domestic), so they are the most feared and the most dangerous dolphin species in the wild.
In 2008, this species was ranked by the International Union for Conservation of Nature (IUCN) as being Least Concern, due to its population not being effected by human activities from humans such as making dams, overfishing, etc, as California river dolphins had adapted to deal with human activities. This species of river dolphin is also to adapt into polluted waters, something that most other whale species haven't adapted to yet.
It is one of the only species of river dolphin kept in captivity, along with the Amazon river dolphin, mainly in the United States, Venezuela and Europe; unlike Amazon river dolphins, however, California river dolphin is easily trained (more so than bottlenose dolphins) and can easily adapt to captive life in aquariums, pools, and other forms of captivity, making it the easiest river dolphin to keep in captivity, even chlorine-filled pools won't kill nor harm them. They also don't require as much food as any other similar-sized or smaller dolphin species, requiring only half as much food as bottlenose dolphins, so its much cheaper to feed them. Also unlike the ones in the wild, the captive ones aren't aggressive nor prey on humans, dylanuses, nor any other large land animals, so these captive bred/raised dolphins are legal to keep as pets, aquarium park animals, etc in most of North America.
|Black Beluga Whale|