Untitled Flashcards Set

What are the two subphyla within Phylum Chordata?

Urochordata (Tunicata) and Cephalochordata.

What do tunicates and sea squirts belong to?

Subphylum Urochordata (Tunicata).

Where are lancelets found?

In shallow tropical oceans.

What is a notochord?

A flexible skeletal support present at some stage of all chordates.

What type of nerve cord do all chordates have?

A hollow nerve cord that runs along the back.

What are pharyngeal slits?

Slits through the body wall in the pharynx, part of the gut immediately behind the mouth.

What is the function of the post-anal tail in chordates?

To provide muscle segments used in movement.

What is an endoskeleton?

An internal skeleton made of bone or cartilage.

What is the vertebral column?

A series of vertebrae that surround and protect the spinal cord in vertebrates.

What type of skeletal material replaces the notochord in vertebrates?

A vertebral column made of bone and cartilage.

What is neural crest?

A group of cells that develop from the nerve cord and form various structures in vertebrates.

What type of circulatory system do all vertebrates have?

A closed circulatory system.

How many species of fish are there?

Approximately 24,000 species.

What is one of the primary functions of fish fins?

To provide balance, steering, and propulsion.

What type of scales cover most bony fish?

Ctenoid scales.

How do gills function in fish?

Gills allow for respiration in water by diffusing gases as water passes across them.

What is the primary method of reproduction for most fish?

External fertilization through spawning.

What is a distinctive feature of hagfish?

They are jawless, eel-shaped fish that feed on soft-bodied invertebrates and dead fish.

What is the difference between jawless fish and cartilaginous fish?

Jawless fish lack jaws and have a notochord, while cartilaginous fish have jaws made of cartilage.

What are some characteristics of cartilaginous fish?

Skeleton made of cartilage, several rows of teeth, and internal fertilization.

What type of fish are ray-finned fish?

Bony fish with a bony skeleton and thin spine-like structures supporting fins.

What is unique about lobe-finned fish?

They have muscular fins with joints, making them more flexible.

Where was the coelacanth thought to be extinct?

It was thought to be extinct until one was caught in 1938 and another in 1997.

What are bioindicators in the context of fish?

Species whose numbers decline due to habitat alteration or pollution.

What major adaptations do some fish have for breathing in low oxygen conditions?

Lungfish have structures similar to lungs.

How do fish excrete waste?

Through kidneys that filter materials from the blood.

What is the size range of the brain lobes found in fish?

Cerebellum, olfactory bulbs, optic lobes, cerebrum, and medulla oblongata.

What role does the swim bladder serve in fish?

It helps fish control their buoyancy in water.

What structures are formed by gill filaments in fish?

Structures that facilitate gas exchange, containing lamellae.

What adaptations help fish detect movement in water?

The lateral line system.

What type of fertilization occurs in cartilaginous fish?

Internal fertilization.

What is one commonality between all vertebrates?

Having a spinal cord protected by vertebrae.

What type of fish are known as top predators in aquatic environments?

Many species of cartilaginous fish such as sharks.

How do scales differ among various types of fish?

Ctenoid and cycloid scales for bony fish, placoid scales for cartilaginous fish, and ganoid scales for some.

What do fish use to maintain salt and water balance?

Kidneys.

What is the diet of ancient fish believed to be comprised of?

Most likely filter feeders or scavengers.

What effect do dams have on fish populations?

Dams block migration paths, which can lead to population declines.

What type of scales cover most bony fish?

Ctenoid scales.

What type of scales are found in cartilaginous fish?

Placoid scales.

What type of scales are present in some fish and are characterized by a bony structure?

Ganoid scales.

What are cycloid scales?

A type of scale found in some bony fish, characterized by a smooth, rounded shape.