Table of Contents
Types Of Dolphins
For an animal which is so instantly recognizable, the dolphin comes in many different shapes and sizes. There are 40 different species of dolphin across the planet, which are split across 17 different genera. A genera is a term used to group together species of animals of the same name but which share similar features. They help to distinguish between the species and to show the evolutionary links between different species. The 17 different genera of dolphin are as follows:
Delphinus, Tursiops, Lissodelphis, Sotalia, Sousa, Stenella, Steno, Cephalorhynchus, Grampus, Lagenodelphis, Lagenorhynchus, Orcaella, Peponocephala, Orcinus, Feresa, Pseudorca and Globicephala.
One of the easiest differentiations to make between different types of dolphin is that between freshwater and saltwater dolphins. River dolphins and marine dolphins are very similar in many ways and they both belong to the overall classification of ‘cetaceans’, but they do differ quite dramatically in appearance. River dolphins have much longer beaks than saltwater dolphins. They also have eyes which are smaller and less effective as there is no point having a fantastic sense of sight when they live in such muddy water.
Their vertebrae are unfused, unlike marine dolphins, which allows them to be very flexible in order to move easily around obstacles caused by flashfloods. Marine dolphins swim much further each day than river dolphins, simply because they live in a more open space which is easier to move around.
Aside from the 40 known species of dolphin across 17 different taxonomic genera, a number of hybrid types of dolphins have begun to crop up across the world. In 1933, three dolphins were beached on the coast of Ireland. They were unlike any dolphins ever recorded before and it soon became apparent that they were hybrids between Risso’s dolphins and bottlenose dolphins. This was a combination which was later recreated with dolphins in captivity which successfully produced a hybrid calf. Further cross-breeds were also produced in captivity between rough-toothed dolphins and bottlenose dolphins.
There have been several other reported cases of bottlenose hybrids living in the wild and a common-bottlenose cross-breed currently lives at Seaworld in San Diego. Perhaps the most well-publicized dolphin hybrid to be born in captivity was is the wolphin, a cross between a false killer whale and a bottlenose dolphin. There are two of them currently living in captivity in Hawaii and they are a fertile pair. Although these wolphins were bred in captivity, there have been numerous sightings of wolphins in the wild.
Types Of Dolphins