Fishes

Question 1

What water qualities affect fishes?

Answer 1

Ammonia
Nitrite
Nitrate
Chlorine
Temperature
Dissolved Oxygen
pH
Suspended solids/sediment
Carbon dioxide
Nitrogen supersaturation

(CCAC, 2005)

Question 2

What are the categories of fish species based on temperature and what are they based on?

Answer 2

Cold water species < 19 C
Cool water species 19 to 25 C
Warm water species > 25 C

(Holm et al, 2021)

Question 3

What is a fish?

Answer 3

An animal, specifically an ectothermic aquatic chordate, that lives in the water (both fresh water and marine), breathes through gills (accessory organs may be used), has multiple differing adaptations that make them well-suited to the environment in which they live (their habitat), and has limbs in the forms of fins (if it has limbs).

(BIOL 4503 Notes)

Question 4

What percentage of fishes live in freshwater? Why is this surprising?

Answer 4

41%

Surprising as freshwater is only ~0.01% of available aquatic habitat.

(BIOL 4503 Notes)

Question 5

Why is there such high diversity in freshwater fishes?

Answer 5

Lots of niches provide the opportunity to specialize and speciate.

There is a lot of disturbance in freshwater (e.g., landslide, flooding).

Allopatric speciation - species gets separated geographically - there are more disconnected populations in freshwater than saltwater.

(BIOL 4503 Notes)

Question 6

How big is a fish’s home range?

Answer 6

Rarely more than 10km.

(OMNR, 2004)

Question 7

What do we need to know about handling fish?

Answer 7

A fish is never better off from human interaction.

Keep wet.

Minimize time out of water.

They have a slime layer that helps protect them from pathogens; surfaces need to be wet before placing them on it to protect this layer.

All capture techniques have the potential to injure, stress, or kill (e.g., scale loss, tissue damage, crowding, predation).

Useful to understand fish physiology an environmental tolerance (e.g., temperature tolerances, dissolved oxygen needs).

(BIOL 4503 Notes)

Question 8

How does turbidity impact fish?

Answer 8

Reduction in light.

Can reduce plankton production, algae production, and diversity of macrophytes causing decrease in zooplankton (an important food for fish).

Impacts feeding and predation.

Reduces effectiveness of predators increasing survival of prey.

(Jude & Pappas, 1992)

Question 9

Describe the relationship between temperature, dissolved oxygen, and fishes.

Answer 9

As most fishes are poikilothermic their metabolism and life processes (e.g., growth, reproduction) depend upon the temperature of their surrounding environment and they can only tolerate temperatures within a given range.

Body mass, temperature, and oxygen have the biggest impact on metabolic rate within fishes.

Fishes also have a minimum threshold at which they require dissolved oxygen levels to be at to perform respiration and at levels below this hypoxia can occur and when dissolved oxygen is too high fish can be impacted as well.

(Currie & Evans, 2021; Marshall et al., 2021)

Question 10

How do temperature and oxygen impact fish feeding?

Answer 10

Feeding rates increase with an increase in temperature until the fish approaches its upper lethal limits, where activity is reduced.

Hypoxia generally decreases fish appetite.

(Currie & Evans, 2021)

Question 11

How do my fish species normally use wetlands?

Answer 11

In a study performed by Jude & Pappas in 1992 on Great Lake coastal wetlands they found white suckers to be one of the most commonly found fish in wetlands, northern pike are rarely found in wetlands, and muskellunge and walleye are rarely to never found in wetlands.

White suckers , northern pike, and walleye are all migratory wetland species that use the wetlands to spawn during the spring and then leave. Northern pike also use them as nurseries.

(Jude & Pappas, 1992)

Question 12

What is the scientific name for walleye?

Answer 12

Sander vitreus

Question 13

What is the scientific name for white sucker?

Answer 13

Catostomus commersonii

Question 14

What is the scientific name for northern pike?

Answer 14

Esox lucius

Question 15

What is the scientific name for muskellunge?

Answer 15

Esox masquinongy

Question 16

Spawning

Answer 16

Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, to spawn refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and reptiles, reproduce through the process of spawning.

(Wikipedia)

Question 17

Nursery

Answer 17

A nursery habitat is a subset of all habitats where juveniles of a species occur, having a greater level of productivity per unit area than other juvenile habitats.

(Wikipedia)

Question 18

What are a white sucker’s feeding habits?

Answer 18

White suckers feed on invertebrates on the bottom and sometimes on fish eggs.

(Holm et al., 2021)

Question 19

Describe white sucker spawning.

Answer 19

They migrate upstream in the spring spawn around 10C where eggs attach to gravel.

(Holm et al., 2021)

Question 20

Describe muskellunge spawning.

Answer 20

Muskellunge spawn in the spring around 10C where they were born in heavily vegetated areas.

(Holm et al., 2021)

Question 21

Describe muskellunge feeding habits.

Answer 21

They are ambush predators that hide within vegetation to await their prey that often includes other fishes, and sometimes other vertebrates (e.g., frogs, mice, etc.). Also eat zooplankton for the first few weeks after they are born.

(Holm et al., 2021)

Question 22

Describe northern pike spawning.

Answer 22

Use heavily vegetated areas for spawning in spring around 5C.

Broadcast spawners - lots of eggs.

(Holm et al., 2021)

Question 23

Describe northern pike feeding habits.

Answer 23

They are ambush predators that hide within vegetation to await their prey that often includes other fishes, and sometimes other vertebrates (e.g., frogs, mice, etc.). Also eat zooplankton for the first few weeks after they are born.

(Holm et al., 2021)

Question 24

Describe walleye spawning.

Answer 24

Walleye spawn around 2C in gravelly areas.

Photoperiod regulates the annual
egg and sperm maturation development cycle, whereas temperature induces actual spawning
activity.

Broadcast spawn - lots of eggs - stay attached a few days then float downstream on current.

Iteroparous

No parental care.

Show fidelity to spawning areas.

(Holm et al., 2021; https://fisheries.org/docs/books/55065P/7.pdf)

Question 25

Describe walleye feeding habits.

Answer 25

They feed near the bottom at night where they move into shallow areas to feed on fishes, other small vertebrates, and invertebrates due to their eyes that are well-suited to the dark; this is also why they are usually in deep water during the day though they can sometimes also be found in very heavily vegetated areas during the day.

(Holm et al., 2021)