Agnathans and fish

Question 1

what are some characteristics of the subphylum vertebrata

Answer 1

1) cranium to protect brain
2) vertebral column
3) tripartite brain

Question 2

what is the name of the jawless fish vs jawed fish

Answer 2

agnatha = jawless

gnathostomata = jawed

Question 3

what are the classes of the agnathous

Answer 3

1) myxini
2) pteraspidomorphi
3) petromyzontida

Question 4

which class of agnathous is extinct

Answer 4

pteraspidomorphi

Question 5

what are some features the agnatha

Answer 5

• no jaw
• true teeth are absent
• paired fins are absent
• single nostril
• scaleless
• cartilage skeleton

Question 6

what are some characteristics of hagfish (myxini)

Answer 6

• elongated eel-like bodies
• marine deep water
• produce large amount of slime

Question 7

what are some characteristics of the class petromyzontida

Answer 7

• fresh and saltwater
• tooth funnel- like sucking mouth
• larvae called ammocoetes

Question 8

what are some characteristics of gnathostomes

Answer 8

• jaw
• teeth
• paired appendages
• modification to ear

Question 9

what is a heterocercal tail

Answer 9

when the upper lobe of the tail is larger than the lower lobe

Question 10

how do shark and rays identify pray

Answer 10

large olfactory organs
- mechanoreceptors in the lateral line sense low frequency vibrations from far away then vision at close range

Question 11

what are some characteristics of chondrichthyes fertalisation

Answer 11

have internal fertilization

Question 12

what are ovoviviparous species

Answer 12

when the embryo is retained in the uterus nourished by yolk = no placenta

Question 13

what ate viviparous species

Answer 13

when the embryo receives nourishment through a placenta

Question 14

what are the three subclasses of actinopterygii

Answer 14

1) chondrosteans
2) neopterygians
3) teleosts

Question 15

what is the name of the muscles which are used by fish for locomotion

Answer 15

myomeres

Question 16

what are the 5 types of locomotion in fishes based on their body movements

Answer 16

1) anguilliform
2) sub-carangiform
3) carangiform
4) thunniform
5) ostraciiform

Question 17

what is the difference between anguilliform and ostraciiform fish

Answer 17

1) the whole body moves in a sinusoidal wave

2) only the tail fin itself moves whilst the body remains still

Question 18

how do more primitive fish remain buoyant

Answer 18

a pneymatic duct which connects to the swim bladder and esophagus

Question 19

what are catadromous fish

Answer 19

enter the ocean as adults migrating from fresh water to their spwaning area where they die before larvae make way back to streams

Question 20

what are anadromous fish

Answer 20

fish which spend their lives only in the ocean and return to fresh water to spawn