Cetaceans (Toothed & Baleen Whales)

Cetaceans (Toothed & Baleen Whales) By: Christa Jewett, Instructor For since the creation of the world God s invisible qualities His eternal power and divine nature have been clearly seen, being understood from what has been made, so that people are without excuse. Romans 1:20

Taxonomy Kingdom Animalia: Animals Phylum Chordata: Chordates Class Mammalia: Mammals Order Cetacea: Whales, Dolphins & Porpoises Suborder Mysticeti: Baleen Whales Suborder Odontoceti: Toothed Whales

Baleen Whale General Information Baleen whales are usually larger than toothed whales. Baleen whales share many of the same physical characteristics as toothed whales including: A melon (oil-filled sac) A thick layer of blubber A blowhole They are characterized by their baleen which is used for feeding as it aids in the capture of large amounts of very small prey.

Baleen Whale General Information Baleen grows from the roof of the mouth of the baleen whales and hangs down in structures called plates. Baleen is made out of keratin, just like our hair and fingernails. Baleen works like a strainer to filter small animals out of the water. The plates of baleen overlap a little and have a fringe to trap food on the inner side. There may be anywhere from 200 to 600 plates in their mouth.

Baleen Whales Right Whale Photo Credit: NOAA (http://www.nmfs.noaa.gov/pr/images/cetaceans/rightwhale_baleen_georgiadnr_permit15488.jpg)

Baleen Whales Photo Credit: Michelle Dubes

Feeding Methods - Skimmers Sift plankton directly out of the water. Swim close to the surface with their mouths open. Best method for capturing slow, surfacedwelling zooplankton that cannot swim away from the whale Examples: Right whales and Bowhead whales.

Feeding Methods - Gulpers Have specialized pleats, or folds in their throats that expand out like a huge bag. They feed by taking huge amounts of water into their mouths, trapping the prey inside. The pleated throat balloons out to hold the water and food. The whale forces the water out past the baleen and the food gets trapped in the baleen. Gulpers are very good at catching fast swimming food such as krill or small schooling fish. Examples: Humpback whale and blue whale

Feeding Methods - Suckers Bottom-feeding whales travel down to the bottom of the ocean to feed on small shrimp-like crustaceans called amphipods. They roll over on one side of their bodies and suck up large mouthfuls of mud. As they travel back up to the surface, they squeeze out the mud and water through the baleen to trap the amphipods. They use their large, 2,500 pound tongue to lick the amphipods off the baleen and push it down their throats. These whales often leave large craters along the seafloor where they have vacuumed up their dinner. Example: Gray whales

Blue Whale Photo Credit: Wikimedia Commons (http://en.wikipedia.org/wiki/file:bluewhale877.jpg) Photo Credit: Wikimedia Commons (http://en.wikipedia.org/wiki/file:blue_whale_001_body_bw.jpg)

Blue Whale Blue Whale Skeleton Outside University of California, Santa Cruz s Long Marine Laboratory Photo Credit: Bronwen Lea (http://en.wikipedia.org/wiki/file:bluewhaleskeleton.jpg)

Humpback Whale Photo Credit: NOAA (http://www.nmfs.noaa.gov/pr/images/cetaceans/humpbackwhale_noaa_large.jpg )

Toothed Whale General Information Toothed whales are usually smaller than baleen whales. They tend to form tight social groups and can form pods of more than 1,000 individuals. Toothed whales are selective eaters and hunt down individual animals. Toothed whales use their teeth to grab prey. They do not use their teeth to chew their prey but instead swallow it whole.

Toothed Whales Bottlenose Dolphin Photo Credit: Understanddolphins.com

Cetacean Morphology Flukes Dorsal Fin Blowhole Melon Pectoral Fin Rostrum Spotted Dolphin Photo Credit: NOAA (http://en.wikipedia.org/wiki/file:spotteddolphin1.jpg)

Cetacean Morphology Fins Most whales have both dorsal and pectoral fins. In most polar species, the dorsal fin is absent (i.e. beluga, narwhals, right and bowhead whales). Fins are used for balance and steering. The dorsal fin may assist in maintaining the animal s internal body temperature. Flukes Flukes are large appendages at the end of a whale s tail that are made up of fibrous connective tissue. The flukes do not have any muscle or bones inside them. The whale uses its flukes like a human would its swim fins, helping to push the animal through the water.

Cetacean Morphology Blowhole & Breathing Whales, like all mammals, have lungs and breathe air. Toothed whales have one nostril, called a blowhole that is located on top of their head. Baleen whales have two nostrils. The placement of their blowhole allows them to breathe easier while swimming. The blowhole closes tightly underwater so that the animal does not drown.

Cetacean Morphology Rostrum The rostrum is the beak-like portion of the whale s body at the end of its head. You can think of it as the upper jaw of the animal. It aids in the streamline shape of the animal. Melon The melon is a special organ located between the blowhole and the rostrum of toothed whales. It is essentially an oil-filled sack that most marine biologists agree serves as an acoustical lens. The melon helps the whale to focus the produced sounds in a desired direction.

Cetacean Morphology Blubber Whales have a thick layer of fat called blubber. This fat layer in the skin can grow up to 1-foot thick. Benefits of blubber: Insulation to keep warm in the absence of hair or fur Help to provide energy as a food reserve when food is scarce Flotation (Blubber is lighter than water and can help the whale remain buoyant in the water. )

Sound Production Toothed whales produce high frequency sounds when underwater. These sounds are useful for communication and navigation. Using sounds for navigation is called echolocation. Echolocation is extremely useful in an underwater environment where visibility is limited. Baleen whales produce low frequency sounds that can be heard for long distances and are useful for communication. Baleen whales do not have the same sophisticated means of echolocation as toothed whales but they do produce sound and sing elaborate songs.

Echolocation The whale uses its nasal air sacs to make distinctive clicking sounds that are then transmitted out through the melon. These high frequency sounds bounce, or echo off of objects and the returning signal is received through the whale s lower jawbone known as the mandible and then conducted to the inner ear via waxy material in the jawbone. Using echolocation, the whale is able to create a picture of an object in the water, determining its size and distance.

Sperm Whale

Beluga Whale Photo Credit: Greg Hume (http://en.wikipedia.org/wiki/file:beluga03.jpg)

Narwhal

Killer Whale Photo Credit: NOAA (http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/killerwhale_photos.htm)

Bottlenose Dolphin Photo Credit: Robert Jewett, Robert Jewett Photography

Common Dolphin Photo Credit: NOAA NMFS (http://en.wikipedia.org/wiki/file:common_dolphin_noaa.jpg)

Harbour Porpoise Photo Credit: AvampireTear (http://en.wikipedia.org/wiki/file:daan_close_up.png)

Wholphin Photo Credit: Sea Life Park

Cetacean Behavior Breaching: Whale jumps out of the water and splashes back down. Bowriding: Toothed whales often enjoy playing in the wake of large boats or larger whales. Spyhopping: Whale slowly rise straight out of the water, until its eye is above the water surface. After a few moments, the whale sinks back down. Lobtailing: Whale slaps flukes on water s surface. Flippering: Whale slaps pectoral fins on water s surface. Kickfeeding: Feeding method where whale slaps flukes on water s surface to surprise nearby fish. Logging: Whale rests on the surface of the water without swimming.

Breaching Photo Credit: NOAA (http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/rightwhale_photos.htm)

Bowriding Photo Credit: Robert Jewett, Robert Jewett Photography

Spyhopping Photo Credit: NOAA (http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/killerwhale_photos.htm)

Lobtailing Photo Credit: Baldo01 (http://en.wikipedia.org/wiki/file:spermwhale_tail.jpg)

Cetacean Intelligence Photo Credit: Creative Commons (http://whaleresearch.blogspot.com/2009/07/cetacean-intelligence-part-one.html)

Dolphin Rehab