Ib 362 lecture 6
Download
1 / 42

IB 362 lecture 6 - PowerPoint PPT Presentation


  • 80 Views
  • Uploaded on

IB 362 lecture 6. Reproduction, Dispersal and Migration in Marine Organisms. Reproduction. Behavior Regulation/effect of hormones Allocation of resources i.e. somatic vs. non-somatic tissue growth Method/frequency of fertilization Parental Care.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' IB 362 lecture 6' - yagil


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Ib 362 lecture 6

IB 362 lecture 6

Reproduction, Dispersal and Migration in Marine Organisms


Reproduction

Reproduction

Behavior

Regulation/effect of hormones

Allocation of resources i.e. somatic vs. non-somatic tissue growth

Method/frequency of fertilization

Parental Care


Reproduction1

  • dominant/large males select best shelters

  • females select dominate male’s shelter and moves in

  • female will molt and then mate

  • after mating, female waits for shell to harden then moves out

  • other females in waiting move into shelter with olfactory cues

Reproduction

Behavior

North Atlantic Lobster – Homarus americanus


Reproduction2

Reproduction

  • no active searching for mates or pre-spawning behavior

  • females secrete pheromone after molting and any nearby male is attracted

Behavior

Opossum Shrimp


Reproduction3

Reproduction

Behavior

Regulation/effect of hormones

Allocation of resources i.e. somatic vs. non-somatic tissue growth

Method/frequency of fertilization

Parental Care


Lifetime reproduction two basic strategies
Lifetime Reproduction-two basic strategies

  • Iteroparous:

    • spawning possible more than once

    • most fishes and invertebrates

  • Semelparous:

    • spawning only once, followed by death

    • pacific salmon, some eels, lampreys


Lifetime reproduction two basic strategies1
Lifetime Reproduction-two basic strategies

  • Iteroparous:

    • spawning possible more than once

    • most fishes and invertebrates

  • Semelparous:

    • spawning only once, followed by death

    • pacific salmon, some eels, lampreys


Lifetime reproduction
Lifetime Reproduction

What are benefits and potential risks of each strategy?

  • Iteroparous

  • Semelparous


Advantages disadvantages
Advantages / Disadvantages

  • Iteroparous:

    +several opportunities

    + environment unpredictable

    - longevity expected

  • Semelparous:

    + maximum investment

    - unfavorable conditions


Mating systems
Mating Systems

number of mating partners an individual has during a breeding season

  • Promiscuous: little or no mate choice

  • Polygamous: one sex has multiple partners

    • Polyandry: one female, several males - rare

    • Polygyny: one male, several females - common

  • Monogamous: mates stay together, exclusively


Mating systems1
Mating Systems

  • Promiscuous

    • organisms that live in large groups

    • organisms with high fecundity

    • sedentary organisms


Mating systems2
Mating Systems

  • Polygamous – Polyandry / Polygyny

    • none to some parental care

    • nest guarding

    • relatively rare in marine organisms, especially beyond egg stage


Mating systems3
Mating Systems

  • Monogamous

    • defense of territory / resource

    • parental care by both parents

    • relatively rare in marine organisms


Extreme atypical mating systems
Extreme/Atypical Mating Systems

  • Monogamous

Males rely on females for nutrition - internal organs degenerate with

exception of testes


Gender roles
Gender Roles

  • Gonochoristic:gender fixed, determined early

  • Hermaphrodites:either both, or sex change

    • Simultaneous: eggs & sperm at same time

Hamlets


Gender roles1
Gender Roles

  • Gonochoristic:gender fixed, determined early

  • Hermaphrodites:either both, or sex change

    • Simultaneous: eggs & sperm at same time

    • Sequential : sex change during life


Sequential common in several marine fishes most common in wrasse family labridae
Sequential – common in several marine fishes (most common in wrasse family – Labridae)

Lyretail Coralfish:

  • Large aggregations

  • Sex-ratio 36F:1M

    • If x M removed, x F change sex


Sex change
Sex Change in wrasse family – Labridae)

Clownfish – 30 species

  • Two large and several small fish

  • largest = female

  • 2nd largest = male

  • rest = immature(even if same age as mature fish) but hiearchal by size

  • Body size maintained until change


Parental care
Parental Care in wrasse family – Labridae)

very diverse across fishes

Trade-off in resource allocation:

  • few, but high-quality

  • many, but low-quality

?

7

300,000,000


Fertilization
Fertilization in wrasse family – Labridae)

InternalExternal

Transfer of sperm in many invertebrates is via a spermatophore

  • Can be stored internally or attached externally

  • May provide nutrients to female

  • May prevent subsequent matings by other males

  • Decreased surface area


Fertilization1
Fertilization in wrasse family – Labridae)

Transfer of sperm in many invertebrates is via a spermatophore

  • Successful system, why not more common?


Fertilization2
Fertilization in wrasse family – Labridae)

Transfer of sperm in many invertebrates is via a spermatophore

  • Successful system, why not more common?

Metamerism – serial repetition of body regions

= more opportunity for appendage specialization


Fertilization3
Fertilization in wrasse family – Labridae)

  • Rare in invertebrates

  • Becomes more common in “higher” vertebrates

Internal (in body cavity)External


Open spawners in wrasse family – Labridae)

Brooders

External

pelagic

benthic

  • More common in marine fishes

  • Also known as broadcast spawners

  • Some benthic fishes will do it

  • high fecundity


Open spawners in wrasse family – Labridae)

Brooders

External

benthic

pelagic

  • gametes released into current

  • settle to substrate after fert.


Open in wrasse family – Labridae) spawners

Brooders

  • gametes can be stored internally

  • fertilization is external

  • fert. eggs carried (usually by females)

  • until hatching

  • more common in invertebrates

External


Open in wrasse family – Labridae) spawners

Brooders

External

  • parental care of juveniles after hatching

  • does occur but is rare, mostly in fishes

Cardinal Fish


Asexual Reproduction


Dispersal
Dispersal in wrasse family – Labridae)

egg >> larvae >> juveniles >> adults

  • Most marine organisms have a larval stage


Dispersal1
Dispersal in wrasse family – Labridae)

egg >> larvae >> juveniles >> adults

  • Most marine organisms have a larval stage

  • Most freshwater organisms do not

  • Why the difference?


Dispersal2
Dispersal in wrasse family – Labridae)


Dispersal3
Dispersal in wrasse family – Labridae)


Dispersal4
Dispersal in wrasse family – Labridae)


Development larvae
Development - Larvae in wrasse family – Labridae)


Hatch egg to larvae
Hatch – egg to larvae in wrasse family – Labridae)

  • not tied to specific developmental stage

  • water temp and oxygen content

  • tide conditions, time of day, seasonal current changes

Hatching occurs at sunset of night of

strongest ebb tide

Coral Reef Flat Damselfish


Larval stage
Larval stage in wrasse family – Labridae)

Duration of larval stage dependant on resource needs in relation to currents

  • Food, habitat

  • 1 week to 18 months


Larval stage1

  • Two main types in wrasse family – Labridae)

  • Lecithotrophic –with yolk sac, no digestion

  • Planktotrophic – feed while larvae, digestion

Larval stage

  • Name different across taxonomic groups

Zoea – Crustaceans

Amphiblastula - sponges

Veliger – some molluscs

Leptocephalus – some fishes

Hard corals - planula


Larva unknown for many species
Larva – unknown for many species in wrasse family – Labridae)


Migration a directed movement
Migration – a directed movement in wrasse family – Labridae)


Migration a directed movement1
Migration – a directed movement in wrasse family – Labridae)


Migration a directed movement2
Migration – a directed movement in wrasse family – Labridae)


Migration a directed movement3
Migration – a directed movement in wrasse family – Labridae)


ad