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Flashcards in Chordates/fish Deck (17)
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1

Fish diversity:
# of species
# of families
% freshwater
Temp range

28-32,000 species
445 families
39% freshwater
Temp range -2- +44

2

4 classes of fish:

Agnatha (jawless)
Placoderms (extinct)
Chondrichthyes (sharks, Rays, chimeras)
Osteichthyes (bony fish)

3

Agnatha characteristics:

evolution, extinction, physical traits

Evolved 530 MYA during Cambrian
Many extinct during the Devonian (370 MYA)
Jawless
No stomach
Cartilaginous skeleton
No paired fins
2 chambered heart

4

Hagfish Characteristics

30-35 species
Live in deep water; scavengers
Uses slime
No scales
Marine hagfish are isosmotic
Has skull but no vertebral column

5

Characteristics of lampreys

~ 40 species
Osmoregulatory
Parasitic
Larval stage called ammocoete-undergo metamorphosis; filter feed
As adults, suck blood & fluids w/ keratinization teeth

6

Characteristics of Placoderms

Evolution, extinction, major innovations

Evolved 440 MYA during Silurian
Extinct 410-350 MYA

Innovations:
-hinged jaw
-paired fins

7

Characteristics of Chondrichthyes:

Evolution, diversity, physical traits

400 MYA
12 orders, 45 families, 800 species (most are sharks and rays)
Paired fins and hinged jaws
Cartilaginous skeletons; big size
Many use fat for buoyancy (usually in liver)
Osmoregulatory
Stiff fins, ventilation of gills

8

What does the ampullae of lorenzini do?

Allows sharks/Rays/skates to sense electromagnetic fields emoted by prey

9

Characteristics of Osteichthyes (bony fish)

415 MYA
~ 25,000 species
Lobe finned:rise to tetrapods
Teeth fused to jaw bone
Fin rays, flexible
Mucus for protection & to reduce drag
High diversity

10

Fish body forms:

Give examples for:

A) laterally compressed
B) dorso-centrally compressed
C) Fusiform
D) Ovate/truncated

A) mola, flatfish
B) Rays
C) tuna, sharks
D) tilapia

11

Fish feeding strategies:

Generalist
Specialist
Filter feeders
Pursuit hunters (biters) (sharks)
Suction feeding
Slurpers
Pickers
Grazers (parrot fish)
Ambush (eels, flatfish)

12

Reasons for color patterns

Disruption-stripes, fake eye spots
Camouflage
Advertisement (poisonous)
Countershading (blending with open sea)

13

Breeding strategies of fish:

Nests (ex. Garibaldi)
Brooding (seahorse)
Broadcasting

14

Difference between

A) viviparous
B) ovoviviparous
C) oviparous

A) live bearing (like mammals)
B) live birth from eggs inside female
C) birth from eggs outside of female

15

Characteristics of phylum Chordata

Notochord
Dorsal hollow nerve chord
Pharyngeal slits
Muscular tail
Segmented
3 germ layers
endoskeleton
Well developed coelom
Ventral heart

16

Sensory adaptations of fish:

Lateral line: senses pressure; schooling
Chemosensory: smell
Otolith ear bones: balance
Ampulae of lorenzini: electromagnetic fields

17

How do sharks use hydrofoil lift?

They increase their speed to lift higher and decrease speed to sink lower.