Marine Mammals B. Order Pinnipedia • Evolved from terrestrial carnivores • Predators - Fishes, squids • Streamlined bodies • Blubber layer under skin • Inhibit loss of body heat through • Large body size (low surface:volume) • Bristly hair • Many nest in rookeries • Males establish territories and harems
25
Embed
Marine Mammals B.Order Pinnipedia Evolved from terrestrial carnivores Predators - Fishes, squids Streamlined bodies Blubber layer under skin Inhibit loss.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Marine MammalsB. Order Pinnipedia
• Evolved from terrestrial carnivores• Predators - Fishes, squids• Streamlined bodies• Blubber layer under skin• Inhibit loss of body heat through
• Large body size (low surface:volume)• Bristly hair
• Many nest in rookeries• Males establish territories and harems
Marine MammalsB. Order Pinnipedia
1. Seals (19 Species)• Rear flippers can’t be rotated forward
• Bryde’s, Blue, Fin, Humpback, Minke, Sei• Large blue whales may enclose up to 17,500 gallons (70 tons) of water in one gulp• Blue whales eat 3000-5000 kg of food each day!• Short baleen, small dorsal fin, ventral grooves
b. Right whales – 4 species• Bowhead, Northern Right, Southern Right, Pygmy Right• Long, fine baleen, no dorsal fin, no ventral grooves
c. Gray whale – 1 species• Short coarse baleen, no dorsal fin, 2-5 ventral grooves
Marine MammalsC. Order Cetacea
1. Mysticeti (Baleen Whales) – 11 species
Marine MammalsC. Order Cetacea
2. Odontoceti (Toothed Whales) – 66 species• Teeth adapted for a different diet
• Only have 1 blowhole
Marine MammalsC. Order Cetacea
2. Odontoceti (Toothed Whales) – 66 species• Teeth adapted for a different diet• Only have 1 blowhole
a. Sperm whales – 3 species• Sperm, Dwarf Sperm, Pygmy Sperm• Bulbous head contains spermaceti (waxy substance) that may function
in buoyancy and sound generation• Sperm can dive to 3000 m and stay under water for up to two hours!• Feed on fishes and squids, esp. giant squids• Produce ambergris, undigested material in stomach
• Began off New England by late 1600s• 1860s – Explosive harpoon introduced• Early 1900s –Antarctic whales hunted• 1946 – IWC founded• 1972 – US Marine Mammal Protection Act• 1985 – IWC moratorium on commercial whaling• Norway, Japan, Iceland still practice whaling
• IWC allows aboriginal whaling
Marine MammalsC. Order Cetacea
3. Status
Marine MammalsD. Diving
• Adaptations for long and deep dives
1. High hematocrit
2. Muscles rich in myoglobin
3. Reduction of heart rate
4. Flexible rib cage
5. Majority of oxygen in blood and tissues
Marine MammalsE. Echolocation
• Common in dolphins, porpoises, toothed whales • May occur in some baleen whales and pinnipeds