Question 1

Sea snakes spend less than half their time in the marine environment.

Accepted Answer

This statement is false. Sea snakes, as their name suggests, are fully adapted to living in marine environments and spend their entire lives in the ocean. They are unable to survive on land and even give birth to their young in the water.

Question 2

Birds are homeotherms, meaning they maintain a constant body temperature.

Accepted Answer

Birds are indeed homeotherms, they regulate their body temperature to around 40°C regardless of the external temperature.

Question 3

Sea snakes have skin that is ________.

Accepted Answer

Sea snakes have skin that is impervious to salt, allowing them to live in marine environments without dehydrating.

Question 4

Baleen whales lack ________.

Accepted Answer

Baleen whales have a specialized structure called baleen plates instead of teeth, which they use to filter out small organisms from the water. They do have flukes, a dorsal fin, a blowhole, and an ear opening.

Question 5

In the perpetually dark bathypelagic zone, fish tend to be ________.

Accepted Answer

In the bathypelagic zone, where sunlight does not penetrate, many fish and organisms have evolved bioluminescence. This adaptation allows them to communicate, attract prey, or deter predators in the absence of light.

Question 6

The smallest marine mammal is a ________.

Accepted Answer

The smallest marine mammal is the sea otter, which typically weighs between 35 and 65 pounds and can grow up to 4 feet in length. Seals, fur seals, sea lions, and dugongs are all larger than sea otters.

Question 7

Dolphins and porpoises are small-toothed whales.

Accepted Answer

Dolphins and porpoises are both members of the cetacean group which includes all whales, dolphins, and porpoises, and are characterized by their small, cone-shaped teeth.

Question 8

The nekton only include vertebrates such as fish and whales.

Accepted Answer

The nekton include both vertebrates such as fish, whales, and squid, as well as invertebrates such as jellyfish and octopuses.

Question 9

A keystone species is an organism that ________.

Accepted Answer

A keystone species plays a crucial role in an ecosystem, often by maintaining the balance of the food web or affecting the survival of other species. Endangerment, abundance, or living in coastal regions do not necessarily define a keystone species.

Question 10

The countercurrent system of flow is involved in ________.

Accepted Answer

The countercurrent system of flow allows for the maximum amount of oxygen to be extracted from the water by maintaining a favorable concentration gradient throughout the gill structure. This increases the amount of oxygen that diffuses into the blood.

Question 11

A group behavior that is much more common in bony fish than cartilaginous fish is ________.

Accepted Answer

Schooling behavior, where fish swim in coordinated groups, is much more common in bony fish than cartilaginous fish. Cartilaginous fish, such as sharks, tend to be more solitary in their behavior.

Question 12

All of the following are part of the nekton except ________.

Accepted Answer

The answer of All of the following are part of...

Question 13

All toothed whales use echolocation except baleen whales.

Accepted Answer

Baleen whales do not have teeth and instead filter-feed on small prey using baleen plates, so they do not use echolocation.

Question 14

Objections to the "stepping-stone" hypothesis, suggesting that deep-sea hydrothermal vent organisms are dispersed by taking advantage of whale falls (like stepping-stones), include all of the following except ________.

Accepted Answer

The answer of Objections to the "stepping-stone" hypothesis, suggesting that...

Question 15

The Chondrichthyes include organisms such as ________.

Accepted Answer

Chondrichthyes, or cartilaginous fish, are a class of fish that have a skeleton made of cartilage instead of bone. This class includes organisms such as sharks, rays, and skates. Lampreys and hagfish, on the other hand, belong to the superclass Agnatha, which is characterized by jawless fish. Bony fish are a separate class known as Osteichthyes.

Question 16

Sea otters depend on a thick layer of fat (blubber) to stay warm.

Accepted Answer

Sea otters do not have blubber like other marine mammals such as whales and seals. Instead, they have the densest fur of any mammal which traps air close to their skin, providing insulation and keeping them warm in cold ocean waters.

Question 17

The presence of seabirds is a good indicator of ________.

Accepted Answer

Seabirds are often found in areas with high productivity, such as upwelling zones or near feeding grounds. They feed on small fish and plankton, which are often abundant in productive areas. Therefore, the presence of seabirds can be a good indicator of high productivity in the surrounding waters.

Question 18

One conservation method used to protect turtles from trawl nets uses ________.

Accepted Answer

Turtle excluder devices (TEDs) are specifically designed to allow turtles to escape trawl nets. When a sea turtle gets caught in a trawl net, it can become trapped and drown. TEDs are placed in the nets to provide an escape route for the turtles, ensuring their survival. Sonar and acoustic tagging devices may be used in turtle conservation efforts, but they are not specifically designed for protection from trawl nets. Gill nets are not a conservation method, but rather a type of fishing net that can also harm sea turtles.

Question 19

The very large eyes of the giant and colossal squid are adapted to ________.

Accepted Answer

The large eyes of giant and colossal squid are adapted to detect bioluminescence, which is the light emitted by other deep-sea organisms. This adaptation helps the squid locate prey, avoid predators, and communicate with each other in the dark depths of the ocean.

Question 20

The hagfish are the only known vertebrate that is iso-osmotic.

Accepted Answer

The hagfish is the only known vertebrate that is iso-osmotic, meaning its body fluids have the same concentration of solutes as the surrounding seawater.

Quiz 13: The Nekton: Swimmers of the Sea