Fish Ecology

Question 1

Pelagic

Answer 1

Open Water species (eg. Tuna, Salmon, mackerel, anchovy)

Question 2

Demersal

Answer 2

Close to Bottom or Bottom-dwelling” (eg. rockfish, halibut, cod, flounder, haddock)

Question 3

Diadromous

Answer 3

moving between freshwater and marine

Question 4

Molluscs

Answer 4

eg.clams, snails, etc.

Question 5

Crustaceans

Answer 5

eg. shrimp, crabs, lobsters

Question 6

What are the 4 trophic levels?

Answer 6

1. Phytoplankton
2. Zooplankton
3. Prey Fish
4. Top Predators

Question 7

Definition of a fish

Answer 7

• Aquatic
• Poikilotherm - ectothermic/cannot regulate their own body temperature, with the exception of tunas and mackerel sharks which are warm-blooded.
• Vertebrate
• Gills (throughout whole life)
• Often having Scales and limbs (in shape of fins)

Question 8

Rete mirabile

Answer 8

• Complex of veins close together
• Heat exchanger in warm blooded or fast moving fish
• allows greater blood temp than ambient temp

Question 9

Fish measurement - most common

Answer 9

• (postorbital-hypural length). - from the posterior of the orbit to the hypural plate
• Used for adult salmonids on spawning grounds
• hooked nose and tail abrasion can make measuring difficult, so this gets around

Question 10

Other fish measurements

Answer 10

• Girth - measured around the largest diameter. Girth measurements can be an indicator of ecosystem health.
• Head length
• Snout length
• Eye diameter
• Jaw length
• Anal fin base length

Question 11

Meristic measurements of fish

Answer 11

• Vertebrae
• Fin rays
• Lateral line scales
• Scales on sides
• Teeth
• Gill rakers
• Pyloric caeca

Question 12

Pharyngeal teeth

Answer 12

teeth in the back of the throat

Question 13

Branchiostegal rays

Answer 13

curved bones that support the branchiostegal membrane

Question 14

Taxonomy

Answer 14

Academic discipline of defining groups of biological organisms. On the basis of shared characteristics, and giving names to those groups.

Question 15

Nomenclature

Answer 15

The scientific naming of species whereby each species receives a latin or latinized name of two parts; first indicates the genus and second species.

Question 16

Phylogeny

Answer 16

the “tree of life”, hierarchical structure in which every lifeform is related to each other.

Question 17

Genetics

Answer 17

branch of biology that deals with heredity, mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms.

Question 18

Anatomy

Answer 18

a. The body structure of a plant or animal or of any of its parts
b. The science of the shape and structure of an organisms and their parts

Question 19

Zoogeography

Answer 19

is the science that attempts to describe

and explain the distribution of animals in space and time.

Question 20

Orientation of fish, looking left clockwise

Answer 20

left anterior
top dorsal
right posterior or caudal
bottom ventral

Question 21

Fork Length

Answer 21

• From tip of nose to fork in tail

- Used for salmonid juveniles and other fish with clear fork in tail

Question 22

Total length

Answer 22

• tip of nose to end of tail

- flounders, sculpins, others w/rounded tails

Question 23

Counting dorsal and anal fin rays

Answer 23

• Don’t count ones on the right that are short
• go biggest to smallest rays
• for the ones that fuse near the base - call these 1

Question 24

Counting scales

Answer 24

• count above and below lateral line
• dont count the lateral line scale, or at the top or bottom of fish
• start at the origin of the dorsal fin, then count along the natural line