Marine Mammals Whales

Order: Cetacea – 90 species Whales are different from seals and sea lions because they spend their entire lifespan in water. Whales are different from seals and sea lions because they spend their entire lifespan in water. There are two main groups of whales: There are two main groups of whales: 1. Toothed whales 2. Baleen whales

Toothed whales Examples: killer whales, pilot whales, dolphins, porpoises, sperm whale Examples: killer whales, pilot whales, dolphins, porpoises, sperm whale * one blowhole opening * one blowhole opening * eat one prey item at a time/swallow prey whole * eat one prey item at a time/swallow prey whole *feed in the entire water column *feed in the entire water column

Baleen whales Examples: gray whale, blue whale, right whales, humpback whale Examples: gray whale, blue whale, right whales, humpback whale 2 blowhole openings 2 blowhole openings toothless – feed with baleen which is made from keratin. It is a food filtering system. When water is pushed out of the mouth the krill are trapped! toothless – feed with baleen which is made from keratin. It is a food filtering system. When water is pushed out of the mouth the krill are trapped! Keratin is the same Keratin is the same protein found in hair protein found in hair and fingernails. and fingernails. (like stiff straw) (like stiff straw) They eat krill They eat krill (2 inches)/plankton (2 inches)/plankton Feed at the surface Feed at the surface Gulpers vs. skimmers Gulpers vs. skimmers

Comparing Toothed and Baleen Whales Ventral pleats – expand when water is taken into the mouth (found on baleen whales only).

Movement Whales move with an up and down movement of the fluke (powerstroke). Upward movement provides the power! This is different than fish which use a side to side motion. Whales move with an up and down movement of the fluke (powerstroke). Upward movement provides the power! This is different than fish which use a side to side motion. Spyhopping: vertical upward movement to look around. Spyhopping: vertical upward movement to look around. Breaching: Jumping out of the water. Breaching: Jumping out of the water.

Echolocation: Sound travels 4X faster in water than air. Used by whales to communicate. (we will talk about this is more detail when we do notes on dolphins) Sound travels 4X faster in water than air. Used by whales to communicate. (we will talk about this is more detail when we do notes on dolphins)

Diving: Diving: To dive whales….. 1. Hold breath 2. Rapidly exhale (90% of Oxygen exchanged compared to 20% in humans) 3. Take a new breath – DIVE! –Sperm whales – 2 hour dive time –Blue whales – 40 min dive time –Bottlenose whales (dolphins) about 15 min.

Diving facts: 1. Baleen whales don’t dive deep! Why? 1. Baleen whales don’t dive deep! Why? A: Because plankton/krill are found at the surface A: Because plankton/krill are found at the surface 2. Whales have more R.B.C’s than non-diving mammals. 2. Whales have more R.B.C’s than non-diving mammals. 3. When whales dive their heart rate slows dramatically from 85 down to 12 per minute. 3. When whales dive their heart rate slows dramatically from 85 down to 12 per minute. 4. Blood flow to nonessential organs is reduced. 4. Blood flow to nonessential organs is reduced. #3 and #4 together are called bradycardia. #3 and #4 together are called bradycardia. 5. Nitrogen dissolves better at high pressure 5. Nitrogen dissolves better at high pressure ex. Think of the lungs like a pop bottle - lungs collapse – squeezes air to central part of lung where little Nitrogen is absorbed. Oxygen goes directly to blood.