Fish Reproduction Flashcards

Flashcards about Fish Reproduction

What percentage of a fish's weight can be ovaries during reproductive periods?

30-70%

What are the characteristics of fish ovaries?

Paired, large, yellowish in color, granular in texture

What is a common challenge in determining the sex of some fish species?

Many lack sexual dimorphism and dichromatism

What are the characteristics of fish testes?

Smooth, white structure

What anatomical feature do Chondrichthyes use to store sperm?

Seminal vesicle

What anatomical feature do Teleosts use that act as a sperm container?

Sperm duct

What is an interomittent organ in male fish?

Modified fin, such as claspers or ovipositors

What are tubercles on Male Eastern Creek Chubsuckers made of?

Keratin

What purpose do tubercles serve on male Eastern Creek Chubsuckers?

Species recognition, fighting, and defense of nests

What is the duration of Zebra fish embryonic development?

Approximately 3 months

What is a key process that occurs during cleavage in fish embryos?

Early cell division

What is a 'blastula' in the context of fish embryo development?

Early stage of embryo development, when it is a hollow ball of cells

Explain the process of epiboly in fish embryo development.

Spreading and thinning of the ectoderm and movement of the mesoderm and endoderm layers to the inside

What is the main event that occurs during gastrulation?

Formation of the endoderm, ectoderm, and mesoderm

What does gastrulation refer to?

Formation of the gut

What is R-selection?

A selective strategy that favors the production of large numbers of offspring with low survival rates

List three characteristics favored by R-selection.

Large numbers of offspring with low survival rates, short-life span and small size of organism as an adult, little care for offspring

Give an example of a fish that uses R-selection.

Danios

What is K-selection?

A selective strategy that favors the production of few offspring with high survival rates

List three characteristics favored by K-selection.

Few offspring with high survival rates, long-life span and large size as an adult, long term parental care

Give an example of a fish that uses K-selection.

Bonnethead sharks

What are the five major stages of fish development?

Embryonic, larval, juvenile, adult, senescent

What is the saltational theory of development?

Development proceeds gradually, until an abrupt change in behavior occurs once a threshold is reached

What is the alternative theory to saltational development?

The entire process is gradual and stages are arbitrary

What defines the embryonic period in fish development?

The developing individual is entirely dependent on nutrition provided by the mother

What are the three phases of the embryonic period?

Cleavage egg, embryo, free embryo

What characterizes the free embryo stage?

Embryo no longer curled, more fish-like, but still reliant on yolk sac or mother for nutrition

When does the larval period begin?

When the fish is able to capture food

When does the larval period end?

When the axial skeleton forms

What is significant about the larval period in marine fishes?

Mortality is high, and it's a time of larval dispersal

What characterizes the juvenile stage of fish development?

Organs fully formed, but gonads not mature

What is an anadromous life cycle?

Fish that spend most of their lives in saltwater and migrate to freshwater to spawn

Do anadromous fish feed during migration?

No significant feeding during migration

Give two examples of anadromous fish.

Salmon and trout

Where does spawning and growth of juvenile salmon occur?

Freshwater rivers

Why do salmon migrate to saltwater?

To feed, grow, and mature

When does spawning typically occur for salmon?

In the fall

What is a 'redd'?

A nest dug by female salmon using their tails

What are salmon eggs called after they develop?

Alevin

What are alevin called when they leave the nest?

Fry

Where do sturgeon hatch?

Freshwater rivers

Where do sturgeon migrate as sub-adults?

To sea

How long can Atlantic sturgeon live?

Up to 60 years

What is a catadromous life cycle?

Fish that spend most of their life in freshwater and migrate to saltwater to spawn

Give an example of a catadromous fish.

Eels

Do eels typically eat once they enter saltwater to spawn?

Usually do not eat once entering saltwater

Are all eels catadromous?

No – some adults of eels from the Pacific and Atlantic ocean never enter freshwater.

What is the otolith bone chemistry of saltwater-reared eels?

High levels of strontium

What is the otolith bone chemistry of freshwater-reared eels?

Low levels of strontium

Where do European Flounder larvae drift?

Towards shore

Where are juvenile European Flounder common?

Estuaries and rivers of low salinity

Where do adult European Flounder go to spawn?

Saltwater

Where do Thin lipped grey mullet massively migrate to feed?

Freshwater habitats

Where do Thin lipped grey mullet spawn?

Saltwater further offshore

In aquaculture, what hormone is added to female tilapia to change them to males?

Male hormones

For the first 2-3 weeks, what percentage of trout weight should be fed per day?

10%

How often is it ideal to feed trout fry?

Every 15 minutes

What are Non-guarders?

Fish that do not protect their eggs and young after spawning

Describe the breeding characteristics of non-guarders.

Typically breed in large groups without courtship displays or specialized reproductive structures

What are guarders?

Fish that guard the embryos until they hatch

Who typically guards embryos, except among cichlids?

Male

What are bearers?

Fish that carry their embryos and sometimes their young around with them

What adaptation do external fish bearers utilize?

Short-term attachment of embryos to the adult, mouth brooders, carrying offspring in pouches

What are 2 examples of bearers that carry offspring in pouches?

Pipefish and Seahorses

What is are 2 examples of mouth brooding bearers?

Sea catfish and cichlids

What is a characteristic of internal fish bearers?

Females carry embryo and/or young internally and Produce a small number of active offspring

What is the level of courtship for internal fish bearers?

Elaborate or limited

In aquaculture, where are eggs usually produced?

At one facility

How are eggs shipped in aquaculture?

Shipped on ice in shipping boxes and gradually brought up to temperature

What is the recommended stocking density in aquaculture?

1 pound of fish per cubic foot

Why are eggs disinfected?

To keep eggs healthy

What method is used to count eggs?

Von Bayer Method V-trough, electronic egg counter, or displacement method

What are trays used for?

Trays are used to house large numbers of eggs

Are fish vaccinated?

Yes, depending on the species