Marine Biology- 9 Marine Mammals

What are the four types of marine reptiles that exist today?

Sea Turtles, Sea Snakes, Marine Iguanas, Saltwater Crocodiles

What is the status of all species of sea turtles?

All species are threatened or endangered.

What does it mean for a species to be classified as endangered?

A species is under direct threat of survival.

What is the difference between threatened and endangered species?

Threatened species may become endangered, while endangered species are at immediate risk of extinction.

How many species of sea turtles are recognized today?

Seven or eight species.

What are the names of some sea turtle species?

Leatherback, Loggerhead, Hawksbill, Olive Ridley, Kemps Ridley, Australian Flatback, Green Sea Turtle.

What are the upper and lower shells of sea turtles called?

Carapace (upper shell) and Plastron (lower shell).

How do sea turtles reproduce?

They breed at sea with internal fertilization and can store sperm.

How often do female sea turtles typically breed?

Every 2-4 years.

What is temperature-dependent incubation in sea turtles?

The incubation period averages 60 days and the pivotal temperature determines the sex of the hatchlings.

What is the largest species of sea turtle?

The Leatherback sea turtle, reaching over 6 ft and 1000 lbs.

What is the smallest species of sea turtle?

The Ridley sea turtle, measuring 100 cm and 100 lbs.

How many species of sea snakes exist?

55 species.

Where are sea snakes primarily found?

In the Indian and Pacific Oceans.

What is unique about the breeding of most sea snake species?

Most are ovoviviparous, retaining eggs in the female.

What type of habitats do saltwater crocodiles inhabit?

Estuaries, mangrove swamps, rivers, and the open ocean.

What is the maximum length that a saltwater crocodile can reach?

Up to 23 feet.

What is a key characteristic of marine iguanas?

They are only partially aquatic and dive to feed on seagrass.

What are the main characteristics of seabirds?

They are metabolic homeotherms with waterproof feathers and hard-shelled eggs.

What is a notable feature of penguins among seabirds?

They are flightless with wing modifications for swimming.

What are the major groups of marine mammals?

Pinnipedia, Carnivora, Sirenia, Cetacea.

What distinguishes seals from sea lions?

Seals have no external ears and non-rotational back flippers.

What is the lifespan of ringed seals?

Up to 45 years.

What do walruses primarily feed on?

Invertebrates and fish.

What is a defining characteristic of sea otters?

They have dense fur coats.

What is a distinctive feature of sea otters?

They have dense fur coats and small, dexterous forefeet with retractile claws.

What is the average lifespan of a sea otter?

10-15 years.

What is the typical weight range for sea otters?

Up to 39 kg (85 lb).

What is the primary diet of sea otters?

Invertebrates, consuming up to 9 kg (20 lb) of food each day.

Where are sea otters typically found?

In coastal waters no further than 1 km (0.6 mi) from shore.

What is the largest land carnivore?

Polar bears.

What is the typical size range for male polar bears?

2.5-3 m long.

What is the average weight of female polar bears?

150-250 kg (331-551 lb).

What is the primary diet of adult polar bears?

They need an average of 2 kg (4.4 lb) of fat per day, primarily from seals.

What is the habitat of polar bears?

Arctic sea ice, water, islands, and continental coastlines.

What is the estimated global population of polar bears?

21,500-25,000.

What are the three species of manatees?

Amazonian manatee, West Indian manatee, and West African manatee.

What is the average length of adult West Indian and West African manatees?

About 3-4 m.

What is the typical weight range for adult manatees?

363 to 544 kg (800-1,200 lb).

What is the primary diet of manatees?

Herbivores, with a low metabolic rate allowing them to fast for up to 7 months.

What are the two suborders of Order Cetacea?

Toothed whales (Odontocetes) and baleen whales (Mysticetes).

What is a key feature of baleen whales?

They are filter feeders using baleen to gulp and filter food.

What adaptations do marine mammals have for diving?

Rapid breathing, high oxygen retention, and bradycardia (slowed heart rate).

What is echolocation in marine mammals?

The emission of sound waves that bounce back to help locate objects.

What is a common behavior observed in marine mammals?

Vocalizations, play activities, and long migrations.

What is the longest migration recorded for a marine mammal?

The gray whale, over 11,000 miles.

How do marine mammals care for injured members of their group?

Other members will care for sick or injured animals.

What type of fertilization occurs in marine mammals?

Internal fertilization via copulation.

What is delayed implantation in marine mammals?

A reproductive strategy allowing the calf to be born at an optimal time for survival.