Marine Mammal Skeletons: Anatomy and Adaptations

Cetaceans have unique adaptations in their skeleton to facilitate their aquatic lifestyle, including the presence of flippers, a divided tail flukes, and vestigial pelvic bones. These adaptations help with swimming and hydrodynamics in water.

Polar bears have adapted skeletal features to thrive in their environment, such as muscular paws for swimming and paddling through snow, as well as strong neck muscles.

Pinnipeds utilize different techniques for propulsion - phocid rely on pelvic oscillation for a slow and steady movement, while otariid use pectoral oscillation for a faster but less stable motion.

Sea otters primarily use pelvic paddling and pelvic undulation to propel themselves in the water, which is important for hunting and navigating their ocean environment.

When swimming with the ventral surface up, the head and chest are typically out of water, fore limbs are folded on the chest, hind limbs are used for alternating or simultaneous strokes, and may swing the tail laterally. Having more limbs out of water helps in maintaining warmth while swimming.

Ventral surface down swimming refers to the position in which an animal swims with its head and shoulders out of the water, using hind limbs to paddle, while fore limbs are held across the chest. This behavior is typically observed as preparation for diving or for swimming at high speeds.

The correct term for alternating ventral surface up and down swimming in animals is grooming behaviour, where the animal rolls along the axis of its body using only hind limbs for propulsion.

Pelvic undulation is a technique used for propulsion while diving, allowing for vertical flexing of the vertebral column to effectively move deeper in water. This technique is not typically utilized on the surface of the water.

Polar bears use a combination of the unique shape of their feet and muscle movements to navigate efficiently on snow and ice surfaces.

Diving basics involve being able to regulate temperature, navigate, hunt, adjust to different environmental factors, and more. Learning languages spoken underwater, wearing heavy clothing to stay warm, and not considering environmental factors are not essential components of diving basics.

Female sea lions have varying diving durations based on seasons, depths, and activities. The correct answer provides information on the typical diving duration along with the maximum duration and depth achieved.

Stellar Sea Lions typically have longer and deeper dives in Spring and Summer, with females diving deeper than juveniles and during the winter. The maximum diving depth for a Stellar Sea Lion is around 200 meters.

The correct answer provides the specific diving duration information for lactating females of Southern Sea Lions, which includes diving depths and the time spent above water. The incorrect answers present variations in diving behaviors of other groups of Southern Sea Lions to confuse test-takers.

Galapagos Fur Seals exhibit different diving durations based on their age and depth. Young seals can dive for 50 seconds at 6 meters throughout the day, while mature seals dive for 3 minutes at 61 meters mostly at night. The incorrect answers provided do not accurately represent the diving durations of Galapagos Fur Seals.

The correct diving duration for a walrus is 10 mins at 80m. The incorrect answers do not align with the specific diving characteristics of walruses.

Elephant seals are known for their impressive diving capabilities, with different age groups showcasing varying durations and depths. The correct answer provides the diving durations for young, mature, and max individuals, along with the fact that they can spend 7-8 months continuously at sea. The incorrect answers offer variations in diving durations and depths, but they do not align with the actual data recorded for elephant seals.

Weddell Seals are known for spending extended periods underwater during their dives, with some of the longest lasting up to 73 minutes at depths of 750 m. These seals are adapted to diving and foraging in the extreme Antarctic environment.

Hooded seals are known to dive for approximately 52 minutes at depths ranging from 100 to 600 meters, with some being able to reach a maximum of 1000 meters. The incorrect answers provided do not accurately represent the diving behavior of Hooded seals.

The skeleton primarily provides support, protection, and structure for the body, along with other functions such as blood cell production and mineral/lipid storage

The pinniped skeleton consists of specific features like large cervical and lumbar vertebrae, 8 true ribs, 4 false ribs, and 3 floating ribs, making the incorrect answers inaccurate.

Sirenians have a unique skeletal structure with large thorax, small lumbar sternum, no fused elements, only 3 ribs attached, and little to no hind limbs.

The sea otter skeleton is distinct with its short neck, numerous attachment points, 10 ribs loosely linked to the sternum, smaller scapula compared to river otters, and webbed skin between toes for increased foot surface area.

Locomotion is affected by a variety of factors including the density and viscosity of the medium an animal is moving through, the need to overcome various physical forces, and adaptations specific to different environments.

The humpback whale's unique pectoral fin is what sets it apart, not its caudal fin. The pectoral fin is distinctive due to its size, shape, and role in the whale's agility.

The caudal fin in marine animals is made up of specific components that contribute to their swimming abilities, such as the cutaneous layer, blubber layer, ligaments, fibrous tissue, counter-current system, and compressed caudal vertebrae.

Caudal Oscillation involves specific movements of the caudal fin and fluke to propel the animal forward by conserving elastic energy.

Sirenians primarily use caudal oscillation and strong strokes for propulsion. Their pectoral fins are kept close to the body, and their flippers are used for flipping, spinning, and 'walking' along the ground.

Northern Fur Seals are known to spend extended periods of time at sea, but not much is known about their specific diving behavior.

Hawaii Monk Seals have been observed diving for an average of 6 minutes at a depth of 10 meters, with a maximum recorded depth of 40 meters. The incorrect answers provided do not align with the known diving behavior of Hawaii Monk Seals.