“The whales do not sing because they have an answer, they sing because they have a song.” Gregory Colbert

Watching whales breach and splash in the oceans is breathtaking. They are majestic inhabitants of the oceans knowing more about the depths than humans have ever seen. In order for whales to survive in the oceans, they have incredible systems humans are still discovering information about but we still have much to learn about whales to help us understand how to help them survive and to understand how they live in the oceans.

While literature is growing in relation to whale ecology, behavior and conservation, research into whale anatomy can indicate:

  • differences between toothed whales and baleen whales
  • further understanding of how these whales live (Berta et al, 2015).

Whale anatomy research included the following interesting information to gain a deeper understanding of whales:



Both toothed whales and baleen whales use their blowhole to:

  • keep water out of their respiratory tract and
  • allow them quick and efficient breathing (Buono et al, 2015)

The anatomy of the blowhole is better known in toothed whales than baleen whales (Berta et al, 2015). Baleen whales have two separate nostrils for paired blowholes, with toothed whales having a single blowhole (Buono et al, 2015).

Baleen whales lack sound capacity using their blowhole for breathing and olfactory purposes (Buono et al, 2015).


Whales have nasal regions (Buono et al, 2015). The olfaction ability in baleen whales may assist in filter feeding and locating their prey with more functional olfactory receptor genes than toothed whales (Berta et al, 2015).

Toothed whales have tissues in their nasal region capable of producing and transmitting sounds for echolocation and communication (Buono et al, 2015).

Research has discovered a “vascular rete mirabile” covering in the lower nasal passage of baleen whales suggesting it could warm inhaled air or may allow for expansion of respiratory space volume as a result of gas compression with increase pressure when diving (Buono et al, 2015).

Sensory Hairs

Sensory Hairs

Sensory hairs commonly called “whiskers” have been suggested for toothed whales but are less known in baleen whales except for the bowhead and sei whales (Berta et al, 2015).

These hairs are suggested to be a type of sinus hairs for prey detection in gray whales who forage on the ocean bottom (Berta et al, 2015).

Fin and blue whales are also suggested to have facial hair growing in patterns of rows by their jaws (Berta et al, 2015).

Throat Gooves

Throat Groves

Both toothed whales and baleen whales have throat grooves; however, these differ in the number of grooves suggested to reflect the different feeding behavior of whale species (Berta et al, 2015).

Due to the large oral expansion of baleen whales during feeding, such as the minke whale, increased sensitivity and elasticity of the throat is needed suggesting the reason for thicker grooves (Berta et al, 2015).



It is suggested a toothed whale’s age can be estimated by counting growth layers in teeth after cutting them in half (Alstrup et al, 2017).

Whale teeth can indicate tissue development like that of internal tree rings (Alstrup et al, 2017).

Whale tooth cut in half for age determination (Credit: Alstrup et al, 2017)

Once the enamel and dentin stop growing, centum (Stock et al, 2017), a calcified substance that has a very high fluoride (Cementum, 2019), then forms a growth record for the rest of the animal’s life (Alstrup et al, 2017).

Cementum covers the tooth roots and anchors the periodontal ligaments that attach the tooth to the mandible (Alstrup et al, 2017).

Whale tooth found on beach near Fourchu, Nova Scotia (Credit: Maria Lisa Polegatto)

Using transmission optical microscopy, seasonal bands can be visible (Alstrup et al, 2017). Toothed whales have wider spaced cementum bands with Beluga whale cementum being cellular with peg like teeth and single roots that continuously grow throughout their lives (Stock et al, 2017).

Beluga Whale
Baleen from deceased Blue Whale at Collingdale Beach near Port Hood, Nova Scotia, September, 2019, (Credit: Maria Lisa Polegatto)


As early in history as 350 BC Aristotle distinguished baleen whales from toothed whales, noting baleen whales have baleen fringes, also called bristles, hairs, fibers, or filaments, they use as a filtration device known as a biomechanical “black box” instead of teeth (Werth et al, 2016).

It was previously thought baleen whales engulf water filled food, with the water being forced out through the baleen plates with their tongue in one direction and the elastic properties of the throat walls acting together with the food then being swallowed (Werth et al, 2016).

It is now suggested there are two degrees of directionality to the flow field with the speed of flow being controlled by the whale’s tongue and lips (Werth et al, 2016).

Research of baleen plates of fin whales in the Mediterranean Sea suggest these whales reside year round in this location with some individuals migrating to the Atlantic Ocean after investigation of baleen plate contents giving clues to their foraging preferences and locations (Roubira et al, 2015).

Dorsal Fin

Dorsal Fin

The dorsal fin plays an important role in animal hydrodynamics and acts as a thermoregulatory function providing them with stability when swimming and release of excess heat (Alves et al, 2018).

It ensures success for hunting prey, escaping from predators and controlling their body temperature (Alves et al, 2018).

For orcas the large male dorsal fin allows females to assess the fitness of a male (Alves et al, 2018). Most healthy whales in the wild have vertically straight dorsal fins (Alves et al, 2018).

Documented photographs of dorsal fins, along with tail markings, can be used to investigate the movement of whales in the ocean (Howard, 2019).


Humpback whales have agility when preying due to high efficiency of pectoral fins which are rough with undulated leading edges formed by tubercles giving them performance skills of delaying stall and an improvement of lift to drag ratio (Shi et al, 2019).

The design of these whale flippers has led researchers to investigate the development and performance of tidal turbine blades (Shi et al, 2019).


The tail of a whale, including other areas of a whale, can be used to identify individual whales, such as humpback whales, from their natural pigmentation and scarring marks.

This process has been used since the 1970’s which has assisted in determining biology, ecology and behavior aspects of whales (Kniest et al, 2010).



A whale’s eye is designed to tolerate mechanical, chemical, optical, and osmotic water conditions while also allowing them to have increased visibility in the ocean and has thickness for protection from damage when diving with temperature changes in the ocean (Rodrigues et al, 2014).

In addition, the eye enables detection and capture of food, identification of other whales and guides them when migrating to other areas (Rodigues et al, 2014).

A whale uses its eye primarily to detect light instead of focusing and it is suggested to be retractable to endure the high pressures of the deep sea (Alstrup et al, 2017).

The retinas of both toothed whales and baleen whales is similar (Berta et al, 2015). Blue whale eyes have rods to see in dim light, but they do not have cones which are for color detection; therefore, they see color as grey shades (De luliis and Haddrath, 2017).


Dorsal view of the tympanic bone and ossicles from Tursiops truncatus. This view is also a particularly good vantage point from which to view the structures that receive the dorsal branch of the mandibular fat body. Subtle, but potentially important, landmarks are: two very thin bony locations marked by the prominent red and blue circles. The S-shaped black dotted-line marks the mallear ridge. The shorter black dotted line marks the ridge along the accessory ossicle. The small red dotted-line marks the sulcus for the chorda tympani. The tympanic bone is colored cyan, and the ossicles are colored as follows: malleus = yellow, incus = magenta, stapes = green. Credit: Cranford et al, 2010

Whales rely on sound to hear with toothed whales using a biosonar system for hearing called echolocation to observe their ocean environment (Yamato, et al, 2014) which is likely the reason this species has obtain evolutionary success and allows beaked whales and sperm whales into low visibility waters of great depths (Lambert, 2016).

Whales ears are narrow and sometimes have a discontinuous channel outside of the skull in the “tympano‐periotic complex” (TPC) which reduces bone conduction to aid them in directional hearing ability (Yamato, et al, 2014).

The TPC has bones of differing thicknesses, joints and soft tissues, allowing for complex vibrational states of sound that reach the TPC through a pathway in the throat (Cranford et al, 2010).

Most toothed whales ears are separated from the skull by ligamentous fibers to acoustically isolate the TPC from skull vibration noises; however, in sperm whales and beaked whales there is a bony connection to the skull suggesting the bone may be a conduction mechanism in these species (Schnitzler et al, 2017).

While sperm whales have a consolidated TPC bone, most toothed whale’s TPC is in two parts (Schnitzler et al, 2017).

Schnitzler et al (2017) further suggest sperm whales have exceptional frequency discrimination ability with a range from 5 to 20 kHz.

The structure of the cochlea in the ears of toothed whales and baleen whales differ significantly making:

  • toothed whales sensitive to high frequency and ultrasonic sound vibrations
  • baleen whales sensitive to low frequency and infrasonic noise (Ekdale, 2016).

Both species have fatty tissues in their ear systems for aquatic sound reception for their auditory ability (Yamato et al, 2014). “Acoustic fats” in the fatty melon of toothed whales’ foreheads remains stable despite body condition (Yamato et al, 2014).

Baleen whales do not use echolocation, instead they rely on sounds of low frequency which can carry over long distances in the water to communicate with potential mates (Yamato, et al, 2014).

Unique analysis of the vibratory complexity of the bony TPC. Unique motions of the head of the stapes in Cuvier's Beaked Whale (Ziphius cavirostris). Vector arrows show the relative magnitude and direction of motions at the head of the stapes for each natural mode of vibration or resonant frequency (the frequency is indicated by the numbers at each arrowhead). The Z axis runs through the head of the stapes and is more or less perpendicular to the footplate, which is in the XY plane. Colors code for frequencies: cold colors are low-frequency and the warm colors are high-frequency. The numbers associated with the arrows indicate the corresponding frequency. Vibrational analysis produces results from calculations based on structure. Credit: Cranford et al, 2010


Minke whales have a thick layer of blubber which is a vascularized hypodermal adipose tissue that allows a whale to have:

  • buoyancy
  • thermal insulation from varying ocean temperatures
  • assists in energy storage
  • is comprised of elastin and collagen fibers (Walquist et al, 2017).

The blubber around a whale’s blowhole is tougher and firmer than the layer of blubber that surrounds the rest of the body (Buono et al, 2015).

The volume and lipid composition of marine mammal blubber changes as a whale’s body condition and diet changes with the highest lipid content in the external blubber, except in pregnant females, with the internal blubber being more indicative of the whale’s diet (Yamato, et al, 2014).

Internal Organs

Internal Organs

Whales are known for diving deep into the oceans, with sperm whales being able to dive 3,000 meters into the ocean and remain underwater for 73 minutes (Tian et al, 2016).

In order to dive, whales need to

  • reduce oxygen delivery to their blood and tissues known as hypoxia (Tian et al, 2016).
  • Whales are able to reduce their heart rate when diving to redistribute and maintain blood flow to their central nervous system and their heart while reducing flow to skin, muscle and organs, such as the kidneys and spleen, to achieve oxygen conservation (Tian et al, 2016).
  • Whales also have a higher concentration of myoglobin which carries oxygen to muscle tissues and allows them to dive for extended periods of time (De luliis and Haddrath, 2017).

The Marine Animal Response Centre (MARS) has further information on whale anatomy at (MARS, n.d.).

If you are in Halifax, Nova Scotia, Canada, stop in to the Museum of Natural History to see their marine exhibit on life sized replicas of whales (Marine, 2015).

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Created By
Maria Lisa Polegatto


Created with images by skeeze - "whale humpback sea" • Pascal Mauerhofer - "When the humpback was hunting for food, he was talking to us. We could hear him perfectly, when we stopped our motor of the boat. This picture was taken in the big bay near Husavik in Iceland. It’s only one of many photos." • NOAA - "Bryde's Whale (Balaenoptera edeni)" • Steve Halama - "untitled image" • Todd Cravens - "untitled image" • Michael Blum - "Breaching" • George Karelitsky - "Humpback Whales in Alaska" • ZIPNON - "whale sea world miami" • saanv vav - "untitled image" • Hans - "killer whale orcinus orca orka" • TR Davis - "humpback whale waving at me like this? I have more here shutterstock.com/g/farbled?rid=71524 " • Jennett Bremer - "untitled image" • Mendar Bouchali - "untitled image" • Georg Wolf - "untitled image" • Ferdinand Stöhr - "While whale watching" • James Lee - "After going what watching many, many, many times, finally got a great picture of a whale diving back into the water."