Marine Biology Exam 3 (vertebrates)

What are the two groups of jawless fish?

Hagfish and lampreys

How does a hagfish get by in life?

Slime that expands upon contact with sea water and helps them untie themselves out of their knots

How do lamprey feed?

As juveniles they are burrowing in the sediment for food, and as adults they are parasitic

How long do lamprey stay as juveniles?

Seven years during which they are growing their gills, teeth, and eyes

What is a cartilaginous skeleton?

A flexible but strong connective tissue found in chondrichthyes

What is the similarity between hagfish and lamprey?

Jawless

Characteristics of Chondrichthyes

Cartilaginous skeletal system

Ampullae of Lorenzini

Serial replacement of teeth (unlimited tooth source)

Four spiral valves

What is cartilage strengthened by?

Calcium

What is the Ampullae of Lorenzini?

Pitted structures found on the side of a shark’s head that detects electrical signals in the water

What is a spiral valve?

A digestive system is shaped like a corkscrew, which maximizes nutrient uptake from prey and facilitates their metabolism. The number of folds in the valves reflects the diet

How do sharks, skates, and rays osmoregulate?

They osmoregulate through their protein system in the rectal gland which empties salt into the environment

What shark lives in a FW environment because of its’ ability to osmoregulate?

Bull sharks found in the Mississippi River to St. Louis

Where can you find Chimaera fish?

They live in the deep ocean, feeding on fish or larger benthic invertebrates. They can be distinguished by their large eyes which help them navigate in the deep sea

What are shark denticles?

Tiny flat diamond-shaped scales decrease drag and turbulence, allowing the shark to swim faster and more quietly

Who’s diet is correlated with long, thin, and pointy teeth?

The Mako, Lemon, and Angel sharks use these teeth to pierce slippery squid and fish

Who’s diet is correlated with jagged and triangular teeth?

The White and Tiger sharks use them to cut or saw chunks of flesh.

Who’s diet is correlated with flat millstone (analogous to molars) teeth?

Rays and skates use these to grind up shellfish and crabs

Who’s diet is correlated with hundreds of tiny teeth?

Whale and basking sharks consume plankton and small fishes.

How do sharks regulate buoyancy? How do bony fish?

Sharks regulate their buoyancy through the oil in their liver. On the other hand, bony fish use a swim/gas bladder to maintain neutral bouyancy

What is oviparity?

Eggs are fertilized in the womb, then the female lays the eggs encased in a leathery pouch called a “mermaid's purse.”

Ovoviviparous reproductive method

Eggs that hatch inside of the womb and the shark has a live birth.

What is viviparity?

An egg develops and hatches inside of the womb. After hatching, the pups live on a placenta until being born alive.

What is chemoreception and how does it help sharks with prey?

They can detect chemicals in the water (i.e. can detect one drop of blood in 10 million drops of water) which helps them find injured animals

What is a lateral line structure?

A network of hair cells that detects water movement and pressure changes

Why are the eyes and spiracles of a ray on the top side?

Allows them to breathe and have a visual of their surroundings while buried in sediment

How to distinguish between male and female sharks?

Males have a pair of claspers at the base of the pelvic fins.

What are the four types of caudal fins?

Heterocercal, Homocercal, Protocercal, and Diphycercal

What is the operculum?

It is a bony plate for protecting the gills of bony fish

Function of the pelvic fin

Keep a fish level preventing it from rolling from side to side

Function of the pectoral fin

Used for propulsion, stability, and help steer and control depth

Anal fin function

Can be hard or soft and is always at the back of a fish, and provides stability

Caudal fin function

Soft rayed, homocercal tail that functions like a motor, propelling the fish forward

Caudal peduncle

Where the vertebrate ends in bony fish

How many dorsal fins do bony fish have?

Two

Which dorsal fin is spiny?

The first dorsal fin is hard with a varied amount of spines

Dorsal fin function

Helps keep the fish upright and aid in turning