Fishes

Question 1

What are the main functions of these different fins?

Answer 1

Paired fins:
Pectoral -help provide lift for animal,
Pelvic – protect the claspers;
Unpaired fins:
Dorsal- provide stability
Anal- also provide stability and help the water flow across the shark
Caudal (Tail)- can be heterocercal , meaning different lengths from top part and bottom

Question 2

How are chondrichthyes different from bony fish? What kinds of fish are found in class chondrichthyes

Answer 2

They have cartilage instead of bones; Sharks and rays

Question 3

What is meant when the tail is described as heterocercal?

Answer 3

it means different lengths from the top of the tail to the bottom

Question 4

What is a nictitating membrane?

Answer 4

it’s protective tissues the covers the eyes of sharks, similar to eyelids

Question 5

What kind of scales do sharks have

Answer 5

placord scales : dermal denticles, they are like teeth

Question 6

How can male and female sharks be distinguished?

Answer 6

Males have claspers and females just have slits

Question 7

How do sharks osmoregulate?

Answer 7

they are isotonic and remain by keeping high concentrations of urea in blood

Question 8

How do sharks breathe?

Answer 8

they have use gills to pass water over and pull out the o2

Question 9

Do all sharks need to swim in order to breath?

Answer 9

No, some sharks can pump water over their gills

Question 10

what is ram ventilation?

Answer 10

when the sharks have to swim in order to pass water over gills to breathe

Question 11

how do rays breathe

Answer 11

using gills on under side

Question 12

How do sharks stay afloat?

Answer 12

they have large livers that are packed with lipids and some can swallow air to help with buoyancy. They have to constantly move in order to stay afloat.

Question 13

What is meant by the terms: oviparous, ovoviviparous and viviparous? What provides the nutrition to the developing embryo in each of these strategies?

Answer 13

Oviparous – eggs left out in environment
Ovoviviparous- eggs are carried in mother and hatch in mother
Viviparous- placental nutrition and live births

Question 14

How do sharks use their senses to track prey at different distances?

Answer 14

They have a really good since of smell eye sight. They have Ampullae of Lorenzini, which allow them to detect bio electric impulses at close ranges and can sense vibrations using lateral lines

Question 15

What are the ampullae of Lorenzini and where are they located?

Answer 15

electroreceptors on the sharks head

Question 16

What do elasmobranchs use electroreception for?

Answer 16

to find prey buried in the sea floor

Question 17

Which species of shark are considered to be the most dangerous for man?

Answer 17

the bull shark

Question 18

Describe the two living groups of jawless fishes

Answer 18

Hagfish: live in cold water and dig burrows in mud, produce slime from mucus glands
Lampreys: primarily freshwater, marine species live in ocean but breed in rivers

Question 19

What are the threats to sharks? What is shark finning? What are the fins used for? What happens to the rest of the shark?

Answer 19

By catch and shark finning; when fisher catch sharks cut off their fins and throw the rest back in the water; are eaten and taken as trophies

Question 20

How are bony fish different from cartilaginous fish? What adaptations are seen in bony fish that are absent in cartilaginous fishes?

Answer 20

True bone in skeleton, flatend scales
Swim bladders, help them stay afloat without swimming , Pectoral fins are used for more functions, Operculum- covers the gills and help pull and push out water of gills

Question 21

What are the two lineages of bony fish? What is the single marine example of sarcopterygii?

Answer 21

Actinopterygii: Ray Finned Fishes
Sarcopterygii: Lobe finned fishes

Question 22

Describe how the body shape of certain bony fish is adaptive to their habitats or lifestyles.

Answer 22

You can tell if they are fast swimmers or floats if their bodies are more stream lined or more bulgy

Question 23

How do bony fish stay afloat? How is this different from how cartilaginous fish stay afloat?

Answer 23

They have swim bladders that the can fill with air to stay afloat. Cartilaginous fish have to stay moving or they will sink

Question 24

What are the features of fast swimming fish? How can you tell by looking at a fish if it is a fast swimmer?

Answer 24

The caudal shape will tell you if the fish is fast. If it has a lunate shaped tail fin they are fast swimmers

Question 25

What is the difference between protandry and protogyny?

Answer 25

When fish have sex changes, if they were male first they are Protandry. If they were female first they are protogyny.