Do dolphins have hair?
SEARCHING FOR DOLPHIN HAIR
BY DR. SAM RIDGWAY
Many haven’t a clue.
Others learn it in school.
I read it in a dictionary.
All mammals have hair.
We are mammals and dolphins are too.
How do dolphins pass this mammal test?
Some say dolphins have whiskers: can this be true?
I am a veterinarian, a research doctor too. I should be able to find whiskers if anyone can.
First, I remove my gloves. Then, I touch the dolphin gently with my fingertips.
I touch the dolphin all over the smooth body. What do I discover? Why, his skin is as slick as an olive!
But, wait! I see. Look with me there on the snout: five small pits but not even a single hair.
We, you and I, have learned an anatomical fact about these graceful mammals of the sea! Think about this a little more.
When the baby dolphin is in his mother’s womb, tiny whiskers fill each of the small pits on his snout; yet, after the baby
slides out of his mother’s body to swim beside her in the sea, his little head moves back and forth. As he swims, the water against his skin pulls on the soft hairs and, soon, they all fall out.
Even after the baby dolphin grows, not a whisker shows.
I shall tell you why: the hair root in each of the pits remains hidden inside.
So, have you discovered why dolphins have hair that they do not show?
For those who still wonder why and have nary a clue, then you must think:
When you want to swim super fast, cover up your hair!
Thanks to Jeanette Ridgway, PhD for help with the words.
Marine Mammals and Sound
In the four pictures above you can see the stages of dolphin hair. Figure A shows the hair root that all dolphins have buried in the skin. Figures B and C show with arrows the hairs that stick out around the time of birth. Figure D shows the dark pits that each contain the hair root below.
Whales, dolphins and other marine mammals communicate with each other underwater. Each species of marine mammal has a unique vocalizations that it uses to communicate with its family, friends and neighbors. Using a hydrophone, (a microphone that can record sounds underwater), scientists are able to listen and record marine mammals as they communicate with each other. The NMMF's Environmental Program works with the U.S. Navy’s hydrophones off the coast of Hawaii to identify different marine mammals in the area. Here is what a False Killer Whale, Humpback Whale, Minke Whale and Sperm Whale sound like underwater.
False Killer Whale (Pseudorcacrassidens)
Weight: Approximately 1,500 pounds (700 kg)
Length: Females: 15 feet (4.5 m) and Males: 20 feet (6 m)
Appearance: Dark gray with some lighter patches near the throat and middle chest
Lifespan: Approximately 60 years.
Diet: Fish and invertebrates like squid
Behavior: They are very social forming strong social bonds, often found in groups of 10-20. They are also often found with other cetaceans, such as bottlenose dolphins.
Humpback Whale (Megapteranovaeangliae)
Weight: 25-40 tons (50,000-80,000 lbs; 22,000-36,000 kg)
Newborns weigh about 1 ton (2,000 lbs; 900 kg)
Length: As large as 60 feet (18 m), with females larger than males
Newborns are about 15 feet (4.5 m) long
Appearance: Mostly dark grey, with some areas of white often on the underside
Lifespan:Approximately 50 years
Diet: Tiny crustaceans such as krill, plankton, and small fish.They can consume up to 3,000 pounds (1360 kg) of food per day
Behavior: Breaching (jumping out of the water), or slapping the surface with their flukes and fins.
Minke Whale (Balaenopteraacutorostrata)
Weight: As much as 20,000 pounds (9,200 kg)
Length: Approximately 35 feet (10 m)
Appearance: Small size whale with black to gray in color and white underside
Lifespan: Approximately 50 years, maturing at around 3-8 years of age
Diet: Tiny crustaceans such as krill, plankton, and fish such as anchovies, dogfish, capelin, coal fish, cod, eels, herring, mackerel, salmon, sand lance, saury, and wolfish
Behavior: Often seen at the surface, they can be seen "breaching" and "spy hopping"; they create sounds including "clicks" and "boings"
Sperm Whales (Physetermacrocephalus)
Weight: Females: As much as 15 tons (13,607 kg) and Males: As much as 45 tons (40,823 kg)
Length: Females: Approximately 36 feet (11 m) and Males: Approximately 52 feet (16 m)
Appearance: Dark gray, sometimes with white patches on the underside, and a very large head
Lifespan: Unknown, but females mature around 30 years old and males mature about 50 years old
Diet: Large squid, sharks, skates, and fish
Behavior: They dive to feed with dives lasting about 35 minutes to depths of 1,312 feet (400 m); however, dives may last over an hour and reach depths over 3,280 feet (1,000 m)
[Source: NOAA Fisheries Office of Protected Species websites.]
DO DOLPHINS HAVE BELLY BUTTONS (NAVELS)?
All humans have a navel.
So do dolphins.
The dolphin navel is not a belly button as some human navels are.
It does not look like a little hole in the belly as some human navels do.
It is not a pouched-out little knot as some of yours are.
The dolphin navel is smooth and slick.
Yet we can see the sign that reminds us of how the dolphin
In its mother’s womb was connected to the placenta
Just as all placental mammals are.
– Dr. Sam Ridgway
Drawing by Jim Corey
The human navel is roughly 62% of height of a standing person from the ground. ( A. Motoc et al. Romanian Journal of Morphology and Embryology 2005, 46(1):63–66).
We have measured the height of the dolphin navel. The dolphin navel lies 53 to 55% of total body length from the lower edge of the flukes as shown in Jim Corey’s drawing.
Note: black box added to original image
In 1490, Leonardo da Vinci made this drawing while working in Florence, Italy. It shows that with our legs spread the right distance apart, the navel is at the center of our body height. Bottlenose dolphins do not have legs. They have a long tail that ends in their flukes. Our measurements show that dolphin’s navels are centered as they are.
For more information on the womb and nourishing placenta connect to Dr. Kurt Benirschke’s web site, http://placentation.ucsd.edu/.
False Killer Whale Vocalizations
Humpback Whale Vocalizations
Minke Whale Vocalizations
Sperm Whale Vocalizations