Freshwater Eco - Unit 2

Active sampling*

Moving gear in order to catch fish. 

Passive sampling*

Collects fish over time as fish swim into it.

Catchability

the proportion of the fish that are available to be captured that is caught by a defined unit of fishing effort

Relative Abundance

the ratio of abundance between two or more locations or species or size classes.

Absolute abundance

the number of fish present in a specific area

Fish density

the number of fish present in a unit of area or volume

Incision

A steep cut in the bank where the bank is a lot higher than where water is flowing. 

Aggrading

When water is flowing over mutliple patches of land, causing a channel that appears braided or patchy

Harmful Algal Bloom

Blooms of toxin-producing algae.

Can leech oxygen from the water, cause the death of wildlife and skin irritation or gastrointestinal problems in humans. 

Endosymbiosis

Interactions between organisms with one organism being within the other

Ephemeroptera

Mayflies. Three skinny tails.

Plecoptera

Stoneflies. Two skinny tails

Trichoptera

Caddisflies. Worm like with plates near the head. Often builds a casing/home with rocks or debris.

Coleoptera

Beetles. Either beetle shaped or larva are worm shaped without plates behind the head.

Diptera

True flies. Worm/maggot like. No legs, sometimes don’t even have an identifiable head.

Odonata

Dragonflies and damselflies.

Damselflies- three paddletails

Dragonflies - big head and abdomen

Megaloptera

Alderflies, dobsonflies and fishflies.

Big jaws, big in overall size, lots of legs

Amphipoda

Scuds

Look like tiny shrimp

Isopoda

Sowbugs

Look like roly polys but don’t roll up

Decapoda

Crayfish

Gastropoda

Snails

Bivalvia

Clams and mussels 

Hirudinea

Leeches

Will have two suckers, one on each end. One sucker is large and the other is small

Platyhelminthes

Flatworms

Very smooth. Shape easily changed. When relaxed, auricles and eyespots

Cyanobacteria

Green. No organelles or nucleus

Diatoms

Very symmetrical. Cell wall made of silica. Protophyte

Dinoflagellates

Distinct groove across them with a flagella coming from it. Protophyte

Euglena

Red eyespot. 1-2 flagella. Protophyte

Green algae

Very diverse. Green with chloroplasts. Protophyte

Amoeba

Constantly changing shape. Lots of arms. Protozoan

Ciliate

Has cilia. Protozoan

Sporozoa

Protozoans that don’t move

Flagellate

Has flagella. Protozoan

Gastrotrich

Big. Shaped like a bowling pin with hairs. Multicellular

Rotifer

Has a ciliated head. Multicellular. Very hardy.

Nematode

Diverse group. Worm shaped. Multicellular

Bryozoan

Sessile and colonial. Creates weird puffy colonies by water. Multicellular

Daphnia

Crustacean. Round body, pointed end

Copepod

Two antenna and two long tails and two egg sacks. Crustacean

Ostracod

Shell goes down on either side, kinda makes an organism hotdog. Crustacean

Walleye

Slender, olive colored, large mouth and eyes

White crappie

White with splotchy vertical black stripes. Dorsal and anal fin are symmetrical

white bass

White with small black horizontal stripes. Strongly arched back 

channel catfish

Smooth olive skin, black whiskers, with one large pair sharply angled. Dark spots and fins

largemouth bass

Olive on top, white on the bottom, separated by a green stripe. Large mouth extending past the eye

gizzard shad

Silvery body, black spot above the temple, long slender ray from the dorsal fin, keeled sternum

blue catfish

Straight edged anal fin, blueish in color, whiskers.

redear sunfish

Pumpkin seed shape. Green body with yellow belly and splotchy dark vertical stripes. Black spot with a red edge at the end of the gill plate. 

bluegill

Pumpkin seed shape. Green body with yellow belly and orange chest. Vertical stripes are lighter in color than the body. 

Selective gear

Gear that is moved to catch fish

Nonselective gear

Gear that fish swim into 

Can fish presence be proven?

Yes. If you look for fish and find them that is proof of presence

Can fish absence be proven?

No, you can only prove that it is highly unlikely for fish to be there

Gill nets

A square mesh stretched between two points. Fish are caught in the openings of the mesh, or entangle themselves in it. Cannot be set perpendicular to strong currents, but may be set parallel to them. Needs depth. Debris is a problem. Highly selective

Fyke traps

A hoop net with wings of mesh. Can trap other wildlife besides fish. Depth doesn’t matter very much. Difficult with debris and strong currents. 

Seines

Mesh that is dragged behind a boat or person, often with a bag behind to catch fish as the mesh is dragged. Can only be used in waters shallower than the seine. Can get snagged. More efficient over smooth substrates. Better at night. 

How does opening in the mesh of nets impact selectivity?

Mesh size can affect fish retention

Electrofishing

Uses an anode to establish an electric field that causes the fish to swim in close proximity and then become immobilized. Typically assistants collect the immobilized fish. Need to be able to see the fish. Bigger fish are caught more often because they are more visible, and netters have a natural tendency to capture them first.

Which sampling technique has the highest mortality? 

Gill nets

How can you tell if a snail is a right snail a left snail?

Hold the coil so that it is pointing away from you, If the opening is on your left, it is a left snail, if it is on your right, it is a right snail.

How to tell a gilled snail from a lung snail?

If the snail is a left snail, it is lunged. 

How to tell a native mussel vs. an invasive Asian clam?

Mussels are larger and longer, more shaped like an oval.

Which orders have some species that live their entire life cycle in water?

Hemiptera, Coleoptera, Amphipoda, Decapoda, Isopoda,

What species of crayfish is most common in our area?

Northern Crayfish

What does EPT mean?

A sensitive group used for measuring water quality. Stands for the three orders it looks for: Ephemoptera, Plecoptera, Trichoptera

Sensitive macroinvertabrates

Mayflies, stoneflies, and caddisflies, dobsonflies, ripple beetles, water pennies, gilled snails

Somewhat sensitive macroinvertabrates

Crayfish, dragonflies, damselflies, craneflies, ripple beetle larva, clams, fish flies, alderflies, scuds and isopods

Tolerant macroinvertabrates

mosquitos, midges, black flies, lunged snails, flatworms, leeches

What does rapid bioassesment use to identify stream health?

Different groups of macroinvertebrates found weighted by level of sensitivity

How to identify left vs right stream bank?

stand in the middle of the water and face the direction the water is flowing (downstream). The left bank is on your left side and the right is on your right.

Signs of nutrient enrichment

The water is green or has a smell

Is it better to have riffles more embedded or less? 

Less embedded

Why is it debated that there is no biogeography for organisms less than 1 mm? Explain both sides. 

No biogeography: 80% of all life less than 1 mm can be found in an area.

Yes biogeography: We don’t know very much about life less than 1 mm and how to identify it/distinguish it from other species

What was the first organism group to evolve photosynthesis? 

Cyanobacteria

Where are red algae usually found?

Marine environments

What groups of algae grows on turtles and mussels?

Green algae

Protophyta

Golden algae, diatoms, dinoflagellates, euglena, green alage

Protozoa

Amoebas, ciliates, sporozoans, flagellates

What are the cell walls of diatoms made up of?

Silica

What is the purpose of cilia and flagella

Movement