Chapter 16

Question 1

The gills of bony fish are covered with a movable flap called the _____

Answer 1

Operculum

Question 2

Teleosts have either cycloid or ______ scales

Answer 2

Ctenoid

Question 3

The ______ is composed of vertebrates having placoid scales, a better recall caudal fin, a ventral mouth, and a cartilaginous endoskeleton

Answer 3

Chondrichthyes

Question 4

A lobe-finned fish thought to have been extinct for 70 million years, but discovered off the coast of South Africa in 1938, is the ______

Answer 4

Coelacanths

Question 5

Unlike other vertebrates, the body fluids of hagfishes are

Answer 5

In osmotic equilibrium with seawater

Question 6

True/False

The ampullary organs of Lorenzini are receptors for detecting weak electrical fields

Answer 6

True

Question 7

True/False

Most fishes are dioecious, with external fertilization and external development

Answer 7

True

Question 8

Sharks have

Answer 8

Placoid scales

Question 9

True/False

The ray-finned fishes are the most numerous and advanced body fishes

Answer 9

True

Question 10

The coelacanths

Answer 10

Were found off the coast of South Africa and Indonesia

Question 11

The propulsive mechanism of a fish is

Answer 11

Its trunk and tail musculature

Question 12

Fishes such as the Atlantic salmon that spend their adult lives at sea but return to fresh water to spawn are called

Answer 12

Anadromous

Question 13

In the gills of fishes, the flow of water is opposite to the direction of blood flow. The efficient arrangement is known as ______ flow.

Answer 13

Countercurrent

Question 14

The fisheries of the Great Lakes were brought to almost total collapse in thei century by the invasion of the _____.

Answer 14

Sea lamprey