Lecture 7 - Chordates

Question 1

Characteristics of Chordates

Answer 1

Notochord, nerve cord, pharyngeal slits

Question 2

Urochordates

Answer 2

Tunicates, pyrosomes. salps
up to 1000 m
Transparent
Vertical migration
Gelatinous

Question 3

C. Larvacea

Answer 3

In subP. Urochordata

Can abandon its “house”

Question 4

Hagfish

Answer 4

2/3000 m 
C. Agnatha
scavenger, specialized on crustaceans
defensive slime
only fish to borrow in the deep sea

Question 5

Chondrichthyes

Answer 5

up to 4000 m

Question 6

Actinopterygii

Answer 6

dense up to 6000 m

up to 8000 m

Question 7

Where are the biggest sharks/fish?

Answer 7

In shallower waters

Question 8

Ceolocanths

Answer 8

600-700 m

has independent fin movement

Question 9

Swordfish

Answer 9

F. Xiphiidae

Forage to 1000 m

Question 10

Color (Mesopelagic fish v. Bathypelagic fish)

Answer 10

M - Silvery sides

B - black

Question 11

Photophores - (Mesopelagic fish v. Bathypelagic fish)

Answer 11

M - Numerous and well developed

B - single, luminous lure

Question 12

Jaws (Mesopelagic fish v. Bathypelagic fish)

Answer 12

M - short

B - long

Question 13

Eyes (Mesopelagic fish v. Bathypelagic fish)

Answer 13

M - Large

B - small, except in anglerfish

Question 14

Olfactory organs (Mesopelagic fish v. Bathypelagic fish)

Answer 14

M - Moderately developed in both sexes

B - Regressed in females, but large in some males (ceratioids)

Question 15

CNS (Mesopelagic fish v. Bathypelagic fish)

Answer 15

M - Well developed in all parts

B - Weakly developed except in lateral lines

Question 16

Myotomes (Mesopelagic fish v. Bathypelagic fish)

Answer 16

M - well developed

B - weakly developed

Question 17

Skeleton (Mesopelagic fish v. Bathypelagic fish)

Answer 17

M - Well ossified, including scales

B - Weakly ossified, scales usually absent

Question 18

Swimbladder (Mesopelagic fish v. Bathypelagic fish)

Answer 18

M - usually present, well developed

B - absent or regressed

Question 19

Gill surface (Mesopelagic fish v. Bathypelagic fish)

Answer 19

M - Numerous gill filaments

B - few gill filaments

Question 20

Color (Midwater Fauna)

Answer 20

E - transparent, reflective, countershading
M - redder/blacker
B - red/black
+ - to white

Question 21

Eyes (Midwater Fauna)

Answer 21

E - medium sized, pigmented
M - large, sensitive but not sharp
B - mostly reduces
+ - reduced

Question 22

Mouth (Midwater Fauna)

Answer 22

E - small
M - Protrusible jaws, some small
B - Large
+ - varied

Question 23

Bioluminescence (Midwater Fauna)

Answer 23

E - some in gelatinous
M - All phyla
B - less, smaller photophores, lures
+ - less

Question 24

Size (Midwater Fauna)

Answer 24

Large animals - largest in shallower waters

Small animals - largest at deeper waters

Question 25

Body forms (Midwater Fauna)

Answer 25

E - good swimmers, fusiform fishes, streamlined shrimp
M - Larger, intermediate
B - Largest, poorer swimmers, eel-like, squat, etc.
+ - largest, poor swimmers

Question 26

Body Structure (Midwater Fauna)

Answer 26

E - robust
M - Intermediate
B - flimsy
+ - flimsy

Question 27

Bouyancy (Midwater Fauna)

Answer 27

E - negatively buoyant swimbladders
M - Approach neutral
B - neutral, no swimbladders except near bottom
+ - same as bathy

Question 28

Deepest fish

Answer 28

Ophidiids
Liparids
Macrourids
Zooarcids