Lecture 16: Fish and Transition to land

Question 1

2 Main types of fish

Answer 1

A) chondrites (caryilaginous fish)
B) Osteichthyes (bony fish)

Question 2

Cartilaginous fish (5 Characteristics)

Answer 2

-Heterocercal tail
-placoid scales
-exposed gill slits
-large pectoral fins
-Mouth is ventral

Question 3

Cartilaginous fish general morphology

Answer 3

Sharks have jaws with rows of teeth, mouth opens to pharynx and gill slits

Question 4

Cartilaginous fish Locomotion

Answer 4

Streamlined body for speed swimming, strong heterocercal tail and large pectoral fins

Question 5

Sharks and rays sensory organs

Answer 5

Great vision with enlarged view fields
olfacctory system to detect 1part / 10 billion (smell)
Lateral line that detects vibrations in water

Question 6

Bony fish (5 characteristics)

Answer 6

-Cycloid/ctenoid scales
-operculum covers gills
-small pectoral fins
-mouth is terminal
-Homocercal tail

Question 7

Main type of bony fish

Answer 7

Teleost

Question 8

Bony fish adaptive radiation

Answer 8

Mouth and jaws have adapted to many shapes and feeding modes

Question 9

Bony fish adaptations

Answer 9

swim bladder grew from gut to help maintain position in the water, lateral line perfected as a sensory organ

Question 10

Lobe finned fish challenges

Answer 10

air is 50x less dense than water so things feel heavier, theres also a higher risk of deiccation (add size and strength to limbs, switch from gills to lungs

Question 11

Amphibians still transitional

Answer 11

1. Reproduction still confined to water
2. eggs are small, mostly unprotected and released in a mass
3. Skin is thin and permeable (ectothermal)
4. skeletons and limbs grow stronger

Question 12

Apona

Answer 12

Snake like
no legs
a few cm to 1.5m long
tropical
blind as adult and breath by skin and lungs

Question 13

Apoda reproduction

Answer 13

Only amphibian with internal fertilization
eggs are still laid in moist ground near water and hatch a tadpole with gills

Question 14

Caudata

Answer 14

Salamanders

Question 15

paedomorphosis

Answer 15

Retention of larval features after reaching adulthood

Question 16

Salamander reproduction

Answer 16

always external, eggs laid in jelly masses
formation of larvae with gills that metamorphose into land adults

Question 17

Anura

Answer 17

Frogs and toads
No tail

Question 18

Anura reproduction

Answer 18

Fertilization is external
eggs deposited in water
tadpoles with gills metamorphose into adults with legs that breath with lungs and skin

Question 19

Amplexus

Answer 19

While female is laying eggs they males comes closer and attaches to her back to add seminal fluid and fertilize the eggs

Question 20

Frogs

Answer 20

Smoother skin
Pointy nose
longer legs, jumps more
live closer to the water
bright colours

Question 21

Toads

Answer 21

Rough skin with warts
broader nose
shorter legs, crawl
explore farther from water
dull colours