Ichthyology Final

What is life history?

How an individual of a species divides its time/energy between growth, maintenance, reproduction, migration, and mortality.

What are iteroparous breeding fish?

Fish that breed multiple times over their lifespan.

What are semelparous breeding fish?

Fish that breed only once in their life. Salmon, freshwater eels, and lampreys.

What is special about the breeding habits of American Shad?

Southern populations (30-33N) are semelparous. Northern populations are iteroparous.

What is special about the breeding habits of Capelin (Arctic smelt)?

Semelparous males and iteroparous females.

What is a promiscuous mating system?

Mass spawning

What is a polygamous mating system?

Multiple partners

What is polygyny?

One male with many females

Polygyny is most common in?

-Territorial nesters

-Leks

-Harems

What is polyandry?

One female and many males

Polyandry is rare but occurs in?

-Some anemone fish

-Deepsea anglers

What is monogamy?

One partner per breeding season or rarely for life

What is determination?

Gender is determined in early ontogeny by genetics or environmental factors.

What is differentiation?

Development of recognizable ovaries or testes

What is maturation?

Production of viable gametes. At this point the fish is an adult.

What does it mean to be gonochoristic? What percent of fish are gonochronistic?

-Fixed separate sexes.

-90%

What are fish that posses male and female parts at one time?

Simultaneous hermaphrodites.

The Black Hamlet (Serranidae) is an example of?

A simultaneous hermaphrodite

What are sequential hermaphrodites?

Fish that are born as one sex but can swap later in life.

What is a protogynous fish?

A fish that is born female but can swap to male later in life

What is a protandrous fish?

A fish that is born male but can swap to female later in life.

This fish is often found in a harem. If the male is lost or killed the most dominant female will turn male. What is this fish?

Cortez rainbow wrasse (Labridae)

What is the size advantage hypothesis for sex change?

Fish change their sex Due to differences in reproductive success that come with changes in size.

Gonads make up what % of body mass in female fish?

70%

Gonads make up what % of body mass in male fish?

12%

How does gender affect size?

Female fish are typically larger. However males may be larger on territorial spawners and protogynous fish.

What are primary sexual characteristics?

Structures that often directly impact reproduction. Ovipositors, claspers, and brood pouches.

What are secondary sexual characteristics?

Colors, tubercles, and display structures.

How is turbidity in Lake Victoria causing the loss of cichlid species?

Visibility is decreased. Male colors are less visible and species are hybridizing at increased rates.

Poecilidae (Livebearers) have what kind of display structure?

A long anal fin for display.

Male fathead minnows develop what kind of display structures?

Mucus pads and breeding tubercles on the snout.

What are the two type of spawn site non-guarders?

-Open substrate

-Brood hiders

What are the two types of open substrate spawners?

-Pelagic (Buoyant eggs)

-Benthic (In veg., sand, or gravel)

What are brood hiders?

Fish that do not guard their nests but hide them.

What are guarders?

Fish that guard their nests

What are bearers?

Fish that keeps their young externally in a pouch or their mouth or fish that keep their young internally in oviducts.

What type of spawner is the grunion?

A beach spawner

What kind of nesters are sculpins and darters?

Crevice nesters

What kind of nesters are sticklebacks?

Vegetation nesters

What are two surface nesting fish?

Bettas and snakeheads

What is internal provisioning?

Young are fed with placenta-like connections or eggs.

What is external provisioning?

Feeding young via various secretions

What is a satellite or sneaker male?

Males that sneak in between another male and female while breeding to try and fertilize the eggs.

What is a jack salmon?

A salmon that returns to breed after only a year in the ocean. They breed by sneaking

What is a parr salmon?

A male salmon that matures without ever returning to the sea. They breed by sneaking.

What is direct development?

Fish that have no larval form. Fish hatch or are born as juveniles.

What is indirect development?

Fish with a distinct larval form. Metamorphize between forms. Common in most fish.

Why are most marine larvae pelagic?

To avoid predation and disperse farther

Life cycle of salmon?

Egg>Alevin>fry>parr>Smolt

What are fry?

Advanced larva or early juveniles

What is smoltification?

Salmon mature, group up, and begin moving towards the ocean.

What are the types of distributions?

-Cosmopolitan

-Endemic

-Disjunct

What is a cosmopolitan distribution?

A distribution that spans most suitable habitat across the world.

What is an endemic distribution?

Located in one small area.

What is a disjunct distribution?

Range is split into two or more separated regions.

What are the two types of disjunct distributions?

-Vicariant

-Dispersed

What is dispersal?

Individuals migrate across an existing barrier

What is vicarience?

A species is separated by a newly formed obstacle

What are the biogeographic realms?

-Oceania

-Antarctic

-Australian

-Afrotropical

-Neotropical

-Nearctic

-Palaearctic

-Indomalaysian

When were plate tectonics discovered?

1960s

When were cladistics discovered?

1970s

When were molecular genetics discovered?

1980s

Why are so many species freshwater despite saltwater being so prevalent?

Freshwater fish are more isolated and the waters are more productive

What is a primary freshwater fish?

A fish that evolved in freshwater

What is a secondary freshwater fish?

A fish that lives in freshwater but can tolerate some salt

What is a peripheral freshwater fish?

A fish that lives in saltwater but can handle some freshwaterW

Primary and secondary freshwater fish are usually?

Freshwater dispersants

Otophysi make account for what fraction of freshwater diversity?

2/3

What is stream capture?

When a stream switches from draining into one watershed to a different watershed

Where is marine species richness greatest?

Warm tropical areas near continents. Specifically the Indo-West Pacific area.

Why does the Eastern Pacific have such little diversity?

Cold currents form the North and South

How do fish communicate?

-Color and display

-Sound

-Chemicals

-Electricity

What is the purpose of color in fish?

-Info: Communication

-Anti-info: Camo

What are some common fish colorations?

-Red

-Poster colors

-Disruptive colors

-Countershading

-Eye ornamentation

-Eye spots

-Stripes

-Polychromatism

What is aposematic coloring?

Bright coloring that advertises toxicity

What is disruptive coloring?

Coloring that blends in and disrupts outlines

What is countershading?

Dark coloring on top to blend in with the water and light coloring below to blend in with the sky.

What is the purpose of eye spots and eye ornementation?

It enlarges the eye and makes the fish look bigger.

What is polychromatism?

Differences in color in a species or population. Females prefer brighter fish but they are more easily spotted by predators.

How is light production used for communication?

It can and illuminate prey or confuse predators.

What is Schreckstoff?

A chemical released by fish in distress that signals danger

What are the types of hierarchies in fish?

-Linear dominance (Largest is dominant)

-Despotic (Fisht for dominance)

What is territory?

A small defended area. Smaller than home range.

What is home range?

The area a fish uses day to day for foraging and surviving

What is an aggregation?

Any gathering of fish

What is a shoal?

A loose social group were fish interact somewhat independently. Often mixed species.

What is a school?

An organized and synchronized group of one species of fish.

What do fish use to help them school?

Vision, lateral lines, and sounds.

Why do fish shoal?

-Hydrodynamic

-Food finding

-Reproduction

-Reduced predation risk

How does schooling reduce predation risk?

Confusion, many eyes, and dilution.

What are some predator avoidance moves of a school?

-Flash expansion

-Compact

-Inspection

-Skitter

-Vacuole

-Fountain

-Stream avoid

-Group jump

What are some impacts of a school being too large?

Not enough prey. O2 depletion.

What fraction of reef fish are diurnal (Day) fish?

½ to 2/3

What fraction of reef fish are nocturnal?

¼ to 1/3

What fraction of fish are crepuscular?

1/10. Mostly predators

What are vertical feeding patterns?

Many fish rest during the day and feed at the waters surface at night.

How do fish use moon phases?

Salmon and eels use the new moon as a signal to head towards the sea. Grunion use a full moon to spawn on the beach.

What is oceanodromy?

Migration within saltwater

What is potamodromy?

Migration within freshwater

What is anadromy?

Migration from salt to fresh (Salmon)