Facts about the animal kingdom

Do Dolphins Have Hair or Fur?

 
María Luz Thurman
By María Luz Thurman, Biologist/ornithologist. December 13, 2023
Do Dolphins Have Hair or Fur?

Dolphins are mammals of the Delphinidae family, which includes more than 90 species of cetacean. One of the common traits of mammals is the presence of hair or fur, something we might not notice when we look at the sleek body of a dolphin. Not all mammals live in the sea, with the vast majority being terrestrial animals. Such adaptations to an aquatic environment may hold the key to whether dolphins have hair or fur. Even these habitats are diverse since there are both marine and freshwater dolphin species.

At AnimalWised, we ask do dolphins have hair or fur? We discover some dolphin skin facts to help us answer this question.

You may also be interested in: Are Whales Mammals or Fish?
Contents
  1. Do dolphins have hair or fur?
  2. Do dolphins have scales?
  3. Facts about dolphin skin

Do dolphins have hair or fur?

Generally speaking, dolphins do not have hair as an adult. Their skin is smooth in both touch and appearance. There is little presence of hair which we most commonly associate with mammals. However, this is in their later stages of development. When they are in their embryonic stage, dolphins do develop some hair which is lost as they mature. Very young dolphins may have the presence of a little hair.

The reason why dolphins do not have fur is due to their environment. Dolphins need to be hydrodynamic to swim fast. Hairs in water slow down animals. For the same reason Olympic swimmers will shave their body, dolphins do not have hair so they can swim faster in the water. This is both to evade danger and to be a better hunter. An example is the orca, one of the most effective and efficient hunters in the animal kingdom.

Learn more with our article on what killer whales eat.

Do dolphins have whiskers?

Just as some of us humans are hairier than others, some dolphins may retain a little bit of hair on the side of their lips. For the majority of dolphins, they will have scattered villi on their snouts (rostrums) during gestation and at the time of birth. These detach shortly afterwards, revealing the hair follicles. In some adult dolphins it is possible to identify shorter vibrissal crypts.

These vibrissal crypt hairs are not true whiskers like those of cats and dogs. True vibrissae are helpful at judging distances and detecting minute changes in their environment. This is because they are attached to sensitive nerve endings that send signals to the brain.

Dolphin whiskers do not have the same complex nerve endings and they are not very long. However, it may be possible they are used to interpret their environment such as detecting changes in water currents. There is some evidence to suggest these vibrissal crypts may also acts as electroreceptors[1].

Do dolphins have scales?

We have seen that dolphins do not have hair as adults. For this reason, some may wonder if they have scales like fish. Fish use scales as a form of protection and to reduce friction in the water. Throughout evolution dolphins have developed scaleless skin to face the challenges and take advantage of the opportunities presented by their aquatic environment without them. This allows them to move efficiently through the water with minimal resistance.

This scaleless skin also plays a fundamental role in the thermal regulation of these animals. Despite their aquatic environment, dolphins are warm-blooded mammals. This means they must maintain a constant body temperature to function optimally. The scaleless skin facilitates the dissipation of heat produced by the dolphins' metabolic activity, allowing them to adjust their body temperature effectively.

The absence of scales on the skin of dolphins is essential for the functioning of their sensory systems, such as vibrissal crypts. As explained above, these allow some tactile perception and interpretation of the aquatic environment. They provide valuable information about the presence of prey, companions or changes in marine currents.

If you want to continue learning about how they perceive the environment and communicate with each other, don't miss our article on the characteristics of dolphins.

Do Dolphins Have Hair or Fur? - Do dolphins have scales?

Facts about dolphin skin

Dolphin skin is soft, smooth, free of scales and hair. It is made up of an outer layer called the epidermis and a thicker inner layer called the dermis. Since they do not have scales like fish do, a dolphin's skin is similar in texture to that of other mammals. Of course, this does not include the hair or fur which is common to terrestrial mammals (although not exclusive).

Some notable features of dolphin skin include:

  • Hydrodynamics: smooth skin contributes to the dolphin's hydrodynamics, allowing it to move efficiently through the water with minimal resistance.

  • Thermoregulation: despite living in water, dolphins are warm-blooded mammals. Scaleless skin helps them regulate their body temperature through efficient heat dissipation. This is common in other types of aquatic mammals.

  • Coloration: dolphin skin coloration varies among species, but they commonly exhibit shades of gray, blue, and white. There are some examples of dolphins with pink skin, although they are much less common.

  • Pigmentation change: some species of dolphins show changes in their skin coloration in response to different conditions. For example, the skin of spotted dolphins can vary in shade depending on water temperature, sunlight and other environmental factors.

  • Sensitivity: although the skin itself is not as sensitive as the vibrissal crypts found in specific areas such as the rostrum (snout), dolphins are able to detect changes in temperature and pressure through their skin, which It helps them in navigation and searching for food.

  • Dermal secretions: dolphins have oil glands in their skin that secrete a fatty substance that helps keep the skin soft and insulated from water. This secretion provides an additional layer of protection and contributes to waterproofing the skin.

  • Unique patterns and markings: each dolphin has unique patterns and markings on its skin, allowing for individual identification. These marks may include scars, indentations, spots and distinctive pigment patterns. Scientists and dolphin watchers use these features to study and track dolphin populations.

  • Cell renewal: dolphin skin is continually renewed. This cell renewal process is essential to maintain the integrity of the skin and ensure that it is in optimal condition for the various activities they perform, such as hunting, communication and navigation.

Together, these characteristics make dolphin skin a unique and specialized adaptation for life in the aquatic environment, allowing them to thrive and function efficiently in their marine environment.

If you want to read similar articles to Do Dolphins Have Hair or Fur?, we recommend you visit our Facts about the animal kingdom category.

References

1. Hüttner, T., von Fersen, L., Miersch, L., Czech, N. U., & Dehnhardt, G. (2022). Behavioral and anatomical evidence for electroreception in the bottlenose dolphin (Tursiops truncatus). Anatomical record (Hoboken, N.J.: 2007), 305(3), 592–608.
https://doi.org/10.1002/ar.24773

Bibliography
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  • Van Dolah, FM, Neely, MG, McGeorge, LE, Balmer, BC, Ylitalo, GM, Zolman, ES, ... & Schwacke, LH (2015). Seasonal variation in the skin transcriptome of common bottlenose dolphins (Tursiops truncatus) from the northern Gulf of Mexico. PLoS One , 10 (6), e0130934.
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Do Dolphins Have Hair or Fur?