Small school / pod of common bottle nose dolphins in the Pacific ocean between Santa Barbara and Channel Islands in California USA. Small school / pod of common On a wooden background of small dark brown dolphins in center lies a vertical row salted dried fish large salt pepper coriander. Small Tranquil Dolphins Cremation Urn Dolphins are often seen as symbols of the spirit, and when shown leaping from the water, they represent life and ascension. The Small Tranquil Dolphins Cremation Urn features several dolphins as they rise together from the waves. Amazon's Choice for small plush dolphin. Wild Republic Bottlenose Dolphin Plush, Stuffed Animal, Plush Toy, Gifts for Kids, Living Ocean, 12' 4.8 out of 5 stars 276. Home › Small dolphin. Regular price $6.00 Sale price $6.00 Regular price. Unit price / per. Write a review →. Collectible Dolphin Figurines; Skip to page navigation. Lenox Porcelain JUMPING DOLPHIN Figurine Retired Accented in Gold Small Porpoise.
Dolphins are small toothed whales, or ‘odontocetes’ which means ‘toothed sea-monster’ in Greek. They are grouped into five families; the ocean dolphins are the biggest family with 38 species; there are also four river dolphin families each with only one member.
All dolphins are highly mobile, powerful predators who hunt fast-moving fish, squid, and other sea creatures. They have super-streamlined bodies, blubber to keep them warm, a single blowhole, and most have a dorsal fin and countershading camouflage which means they are darker on their back than their belly.
The ocean dolphin family is very large and diverse; it has 38 members. The largest ocean dolphins are the orca, pilot whale and false killer whale. The smallest are the New Zealand dolphin and tucuxi. Other ocean dolphins include Risso’s, striped, spinner, spotted, common, dusky, hourglass, rough-toothed, white-beaked, Commerson’s and bottlenose dolphins.
Oceanic dolphins are found in all the world’s oceans and seas and from the equator to the ice edges. However, the majority of species live in warm and tropical waters and only orcas live near the polar ice sheets. Many species prefer off-shore, deep-water habitats, and others are more coastal.
The number of teeth they have ranges from 14 (Risso’s dolphin) to 240 (spinner dolphin). The shape, size and even position of their teeth varies depending on their preferred prey. Most ocean dolphins have lots of conical-shaped teeth which are best for grabbing fish. Squid-hunting specialists, such as Risso’s dolphins, have fewer teeth as they suck the squid into their mouths.
Dolphins are sociable creatures and typical group sizes for the different species can range from a few individuals to larger pods, to those numbering hundreds or even thousands in deep water. Dolphins have an array of vocalisations such as clicks, whistles and squeals which they use for their well-developed communication and echolocation skills. Dolphins are intelligent; examples of behaviour seen in the wild which demonstrates their intelligence includes cooperative hunting, play behaviour, and tool use.
Dolphins give birth to one baby at a time after a pregnancy between nine and 16 months. Mothers feed their babies with their own milk and take care of them for a number of years, during which time they teach their youngsters how to thrive independently. The sons and daughters of resident orcas will stay with their mothers throughout her lifetime. Lifespan varies from around 20 years in the smaller dolphin species to 80 years or more for larger dolphins such as orcas.
Ocean dolphin facts
- 38 species currently
- Inhabit all the world's oceans and seas
- Includes the largest dolphin (orca) and some of the smallest (New Zealand dolphin, Franciscana)
There are four dolphin species and four families that are grouped together as the true river dolphins. The South Asian river-dolphin is known as the Ganges river dolphin or susu in India and Nepal, the shushuk in Bangladesh and the Indus river dolphin or bhulan in Pakistan; the Amazon river dolphin, known in South American countries locally as boto, bufeo or Inia; the franciscana; and the Yangtze river dolphin, known as baiji in China but now extinct (this was announced by scientists in 2007).
The ancestors of river dolphins were marine, but river dolphins look quite different from their modern day ocean relatives. This is because river dolphins look like early or primitive marine dolphins; they have slender beaks with numerous teeth, small eyes, flexible necks and bodies, pronounced forehead melons, large flippers and undeveloped dorsal fins.
Despite sharing many similarities, the river dolphin species live in geographically separate river systems around the world and they are not thought to be closely related to one another. They were separated geographically from one another and have evolved independently for millions of years. Their shared looks are simply down to them all evolving to live in river environments.
One species, the franciscana, is considered a river dolphin, although they live in large estuaries and along the coast of Argentina, Uruguay and southern Brazil. The franciscana is closely related to the Amazon River dolphin and their ancestors are thought to have lived in rivers.
The modern river dolphins now only survive in South America and Asia. Botos live in the Amazon and Orinoco river systems and flooded rainforests of South America. Asian river dolphins live in two separate river systems – the Ganges of Nepal, India and Bangladesh and the Indus of Pakistan. The pink Amazon River dolphin or boto is the best-known river dolphin. In terms of numbers, the boto is the healthiest of the river dolphins mainly because the Amazon has not yet been exploited by humans to the same extreme levels as Asian rivers. However, this situation is rapidly changing as human populations grow and transform rivers for their own needs.
River dolphins are among the most seriously endangered of all dolphins because they live in space-limiting freshwater river systems, amongst millions of people who compete for the same natural resources. Unfortunately the future prospects for river dolphins are likely to worsen as threats to them and destruction of their habitats continue to increase.
River dolphin facts
- Contain four species.
- Found in the major rivers and tributaries of South America and Asia.
- One species, the Franciscana, prefer estuaries and coastal waters.
- The baiji or Yangtze River dolphin, once found in China, is sadly now believed to be extinct.
- Some ocean dolphins also have populations that live in rivers, such as the Irrawaddy dolphin.
Which is the world's most endangered dolphin?
Maui's dolphin is also on the brink of extinction. Maui’s dolphin is a sub-species of the New Zealand dolphin that lives only in coastal waters of part of North Island, New Zealand. Maui’s dolphins are facing extinction; there are now less than 50 individuals left living along a 22-mile stretch of coastline. The problem causing this rapid decline and indeed the decline of Hector’s dolphin (the other New Zealand dolphin sub-species) in South Island is entanglement in fishing nets.
As of now, there are 9 dolphins under the threat of being endangered and some are close enough to go extinct. Dolphins are good indicators for knowing the quality of the waters or the overall ecology so it is important to know why some of them are in danger. So, here are the 9 species of the dolphins.
See also: Ways to Save the Dolphins
1. Hector’s Dolphin (Cephalorhynchus hectori)
The Hector’s dolphins are listed as one of the endangered dolphins in the world. They are considered to be small and rare species of dolphins. The size of an adult Hector’s dolphin is around 1.2 metres and 1.7 metres long. Moreover, their weight can add up to 50 kg. The colour of the Hector’s dolphins is grey but they have a white underbody. Other parts of their body such as the face and the tail are black. They can live for 7 to 9 years.
Furthermore, the Hector’s dolphins are found mostly in New Zealand. It is estimated that only around 7.000 species are left in the waters. There are many reasons why they are endangered. Their habitat is disturbed due to the development of ports. They are also often killed while getting caught in a net meant for fishing. Also, chemical pollution such as pesticides are also disrupting their reproductive system. Thus, hindering the prosperity of their species.
2. Chilean Dolphin (Cephalorhynchus eutropia)
Formerly known as the black dolphin, the Chilean dolphin live in the waters of Chile. They have a grey body with black flippers but their bellies are white. Although they are grey, they turn black once they are dead.
See also: Ways to Save the Ocean
They swim in a group of 10 dolphins. A larger groups can usually consist of 50 dolphins or in higher numbers than that. Chilean dolphins do not exhibit social behaviour. So they usually try to keep a distance when they see humans. Moreover, they can also decide to swim away.
The Chilean dolphins are very small and their meats are used as bait for crabs by the local fisherman. It is now illegal but it is believed that the practice still continues which contributes to their nearly threatened status. Other than that, they are also hunted as food for humans. Since illegal fishing of this dolphin might still continue in unnoticeable ways, their species numbers are threatened.
3. Chinese White Dolphin (Sousa chinensis)
The Chinese White dolphins mostly live in the waters of Southeast Asia. They are famous for their pink whitish colour. However, they are actually black when they are born and gradually changes colour as they transcend into adulthood.
The dolphins turn grey then pinkish during their young years. When they are fully adults, they look more white in colour. The body length of an adult Chinese White dolphin can measure up to 3.5 metres. As for the weight, they can be around 230 kg. Moreover, they can live for 40 years.
These dolphins are known to be very sociable even though they usually swim in a group of four. They like to play around with the young dolphins which enables them to increase their social skills. Unfortunately these dolphins also fall under the near threatened status. It is believed that there are only 2.500 species left and that number keeps decreasing. Increasing number of pollution in the number is a serious threat to these species. Additionally, overfishing and development along the coasts also contribute to their demise.
4. La Plata Dolphin (Pontoporia blainvillei)
The La Plata dolphin takes the title as the world’s smallest dolphins in the world. Despite their small bodies, they have a very distinctive large and long beaks. The male can size up to 1.8 metres while the females are around 1.6 metres. They weigh around 50 kg only.
Small Dolphin Species
See also: Oceans in the World
Additionally, they are grey or brownish in colour. Just like the other previously mentioned dolphins, they also have white bellies. They are mostly found in the waters of South America.
These dolphins do not attract attention while swimming as they move very slowly. A dolphin will either swim by itself or join in a group. The La Plata dolphins are listed as vulnerable species. It is reported that each year, around 500 and 800 species die due to numerous reasons. The fact that they are hunted by killer whales due to their small size could be a contributing reason however, humans are more to blame.
The La Plata dolphins are often caught in nets or other fishing gears which eventually kills them. Their habitat are slowly degraded due to human factors such as pollution and industries. They poison the habitat of these dolphins and also kill off their food.
5. Ganges River Dolphin (Platanista gangetica)
Most of the Ganges River dolphins live in the waters of the Brahmaputra Rivers. It is a river that runs through China, India and Bangladesh. The dolphins have a grey and brownish colour. The young ones have darker tones but as they grow into adulthood, they become lighter.
They have a round belly with a long snout. Also, these dolphins are often called as the blind dolphins although they are not completely blind. It is believed that evolution has made them use echolocation instead to locate their preys in the muddy water. They can grow up to 2.67 metres in size.
Small Dolphin Drawing
The Ganges River dolphins are currently in the endangered status. It is assumed that only around 1.800 species are left. The building of dams alongside the increasing pollution in water are major contributing factors to their declining numbers and habitat. Other than that, they are also still hunted for their meat and oil.
6. Indus River Dolphin (Platanista gangetica minor)
The Indus River dolphins can only be found in Pakistan. More specifically, they live in the Indus river that run through India and Pakistan. It is believed that around 50 million years ago, they used to live in the Tethys Sea. However as the sea begins to dry up, they begin to live in the rivers.They are now completely blind dolphins and survive on echolocation.
The size of these dolphins can reach up to 2.5 meters and they weigh around 110 kg.Their appearance is similar to the Ganges river dolphins. They also have a round belly and a long snout. Moreover, they are brown in colour. Their teeth are also visible even though the mouth is shut.
Also read: Differences Between the Ocean and the Sea
As of now, they are listed as endangered. Currently, there are only 1.100 species believed to exist. However, that number will keep decreasing because of factors that harm their habitat and overall life quality. These factors include pollution in the waters, hunting and entrapment in canals used for irrigation.
See also: Volcanoes under the Ocean
Pesticides, human waste or human products are constantly polluting the waters. They are also often caught in nets or trapped in canals which eventually kill them. Deforestation along the river also reduces the quality of the river which ruins the dolphins’ habitat.
7. Australian Snubfin Dolphin (Orcaella heinsohni)
The Australian Snubfin dolphins populate the northern waters of Australia. They are relatively large with size that could reach 2.70 metres for males and 2.30 metres for females. Moreover, their average weight is around 113 kg.
For their body structure, they have no beak but they do have a round head like a melon. As for their colours, they are often grey or greyish blue with a white belly. The young Australian Snubfin dolphins are lighter in colour but gradually grow darker as they get older. These dolphins have a shy personality and only form small groups.
Also read: Deep Ocean Ecosystems
Unfortunately these dolphins rank as near threatened. Their habitat are at risk of being damaged because of pollution. Harmful chemicals such as herbicides and pesticides as well as industrial sewage reduce the quality of the surrounding waters. Incidental capture in nets also contribute to their depleting number of species.
8. Atlantic Humpback Dolphin (Sousa teuszii)
The tropical waters is the place where the Atlantic Humpback dolphins thrive. They are found in the Atlantic ocean and along the west coast of Africa. They are closely related to the Chinese White dolphin species.
The mature Atlantic Humpback dolphins are around 2.6 metres in length and weigh 139 kg on average. Furthermore, they have medium size snout and a round head. Their distinctive feature is their raised hump on their bodies. For their colour, they are grey and their bellies are lighter shades of grey. They move very slowly and swim in a small groups. Since they are very shy, they tend to avoid human contacts or boats.
Their current status is vulnerable due to many reasons. In West Africa, some people still hunt these dolphins as food. They often die or injured when accidentally caught in nets meant for other fish. Other than that, boats that accidentally collide with their bodies cause them injuries too. Another reason is the degradation of their habitat caused by contamination and also mangroves destruction.
9. Irrawaddy Dolphin (Orcaella brevirostris)
Small Dolphin Stuffed Animal
Most population of the Irrawaddy dolphins are found in the waters of Southeast Asia as well as the rivers of Bay of Bengal. These species are closely related to the killer whales. They have blunt, round head like a melon. Mature dolphins can reach 2.3 metres in size and weigh up to 200 kg. In addition, these species are not very sociable and tend to be shy. They avoid boats and swim away when there are human contacts.
See also:Effects of Sea Level Rise
These species are in the status of vulnerable due to the fact that their population keeps decreasing. Accidental fishing and degradation of habitat become threats for them. Dam buildings and deforestation majorly lower their life quality. However, the Irrawaddy dolphins are sacred animals to the people of Khmer and Lao. Efforts are being made to prevent further depletion of species.
Also read: Ocean Animals
Indeed, most of the causes of their decreasing number in species are due to human factors. There are conservations and regulations to protect them. But they are not enough because humans need to be more aware and cautious with their actions. The result could be catastrophic and the dolphins are the ones who pay for it.
Those are complete explanation about Endangered Dolphin Species in the world, especially in ocean life. After we know, i hope we can be aware about the existence of those dolphins and keep them life.