Upload
yagil
View
27
Download
0
Tags:
Embed Size (px)
DESCRIPTION
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. - PowerPoint PPT Presentation
Citation preview
IB 362 lecture 6IB 362 lecture 6
Reproduction, Dispersal and
Migration in Marine Organisms
ReproductionReproduction
o Behavioro Regulation/effect of hormoneso Allocation of resources i.e. somatic vs. non-somatic tissue growtho Method/frequency of fertilizationo Parental Care
ReproductionReproduction
o Behavior
North Atlantic Lobster – North Atlantic Lobster – Homarus americanuHomarus americanuss
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
ReproductionReproduction
o Behavior
Opossum ShrimpOpossum Shrimp
no active searching for mates or pre-spawning behavior females secrete pheromone after molting and any nearby male is attracted
ReproductionReproduction
Lifetime ReproductionLifetime Reproduction-two basic strategies-two basic strategies
IteroparousIteroparous: : • spawning possible more than oncespawning possible more than once• most fishes and invertebratesmost fishes and invertebrates
SemelparousSemelparous::• spawning only once, followed by spawning only once, followed by
deathdeath• pacific salmon, some eels, lampreyspacific salmon, some eels, lampreys
Lifetime ReproductionLifetime Reproduction-two basic strategies-two basic strategies
IteroparousIteroparous: : • spawning possible more than oncespawning possible more than once• most fishes and invertebratesmost fishes and invertebrates
SemelparousSemelparous::• spawning only once, followed by spawning only once, followed by
deathdeath• pacific salmon, some eels, lampreyspacific salmon, some eels, lampreys
Lifetime ReproductionLifetime Reproduction
IteroparousIteroparous SemelparousSemelparous
What are benefits and potential What are benefits and potential risks of each strategy?risks of each strategy?
Advantages / DisadvantagesAdvantages / Disadvantages
IteroparousIteroparous: : ++ several opportunitiesseveral opportunities
++ environment unpredictable environment unpredictable
-- longevity expected longevity expected
SemelparousSemelparous::++ maximum investment maximum investment
-- unfavorable conditions unfavorable conditions
Mating SystemsMating Systems
number of mating partners an individual has number of mating partners an individual has during aduring a breeding seasonbreeding season
PromiscuousPromiscuous: little or no mate choice: little or no mate choice
PolygamousPolygamous: one sex has multiple partners: one sex has multiple partnersPolyandryPolyandry: one female, several males - rare: one female, several males - rarePolygynyPolygyny: one male, several females - common: one male, several females - common
MonogamousMonogamous: mates stay together, : mates stay together, exclusivelyexclusively
Mating SystemsMating Systems
PromiscuousPromiscuous• organisms that live in large groupsorganisms that live in large groups• organisms with high fecundityorganisms with high fecundity• sedentary organisms sedentary organisms
Mating SystemsMating Systems
Polygamous – Polyandry / PolygynyPolygamous – Polyandry / Polygyny• none to some parental carenone to some parental care• nest guardingnest guarding• relatively rare in marine organisms, especially beyond relatively rare in marine organisms, especially beyond
egg stageegg stage
Mating SystemsMating Systems
MonogamousMonogamous• defense of territory / resourcedefense of territory / resource• parental care by both parentsparental care by both parents• relatively rare in marine organismsrelatively rare in marine organisms
Extreme/Atypical Mating SystemsExtreme/Atypical Mating Systems
MonogamousMonogamous
Males rely on females for nutrition - internal organs degenerate with Males rely on females for nutrition - internal organs degenerate with exception of testesexception of testes
Gender RolesGender RolesGonochoristic:Gonochoristic: gender fixed, determined gender fixed, determined
earlyearly
Hermaphrodites:Hermaphrodites: either both, or sex either both, or sex changechange• SimultaneousSimultaneous: eggs & sperm at same : eggs & sperm at same
timetime
Hamlets Hamlets
Gender RolesGender RolesGonochoristic:Gonochoristic: gender fixed, determined gender fixed, determined
earlyearly
Hermaphrodites:Hermaphrodites: either both, or sex either both, or sex changechange• SimultaneousSimultaneous: eggs & sperm at same : eggs & sperm at same
timetime• Sequential Sequential : sex change during life: sex change during life
Sequential – common in several marine Sequential – common in several marine fishes (most common in wrasse family fishes (most common in wrasse family
– Labridae) – Labridae)
Lyretail Coralfish: • Large aggregations• Sex-ratio 36F:1M
If x M removed, x F change sex
Sex ChangeSex ChangeClownfish – 30 speciesClownfish – 30 species
• Two large and several Two large and several small fishsmall fish
• largest = femalelargest = female• 22ndnd largest = male largest = male• rest = immature(even rest = immature(even
if same age as if same age as mature fish) but mature fish) but hiearchal by sizehiearchal by size
• Body size maintained Body size maintained until changeuntil change
Parental CareParental Care
very diverse across fishesvery diverse across fishes
Trade-offTrade-off in resource allocation: in resource allocation: few, but high-qualityfew, but high-quality many, but low-qualitymany, but low-quality
??
300,000,000300,000,00077
FertilizationFertilization
Internal External
Transfer of sperm in many invertebrates is via a Transfer of sperm in many invertebrates is via a spermatophorespermatophore
• Can be stored internally or attached externallyCan be stored internally or attached externally
• May provide nutrients to femaleMay provide nutrients to female
• May prevent subsequent matings by other malesMay prevent subsequent matings by other males
• Decreased surface areaDecreased surface area
FertilizationFertilization
Transfer of sperm in many invertebrates is via a Transfer of sperm in many invertebrates is via a spermatophorespermatophore
• Successful system, why not more common?Successful system, why not more common?
FertilizationFertilization
Transfer of sperm in many invertebrates is via a Transfer of sperm in many invertebrates is via a spermatophorespermatophore
• Successful system, why not more common?Successful system, why not more common?
Metamerism – serial repetition of body regionsMetamerism – serial repetition of body regions= more opportunity for appendage specialization= more opportunity for appendage specialization
FertilizationFertilization
• Rare in invertebratesRare in invertebrates
• Becomes more common in “higher” vertebratesBecomes more common in “higher” vertebrates
External
Open spawners
pelagic
benthic
• More common in marine fishesMore common in marine fishes• Also known as broadcast spawnersAlso known as broadcast spawners• Some benthic fishes will do itSome benthic fishes will do it• high fecundityhigh fecundity
External
Open spawners
pelagic
benthic
• gametes released into currentgametes released into current• settle to substrate after fert. settle to substrate after fert.
External
Brooders
• gametes can be stored internallygametes can be stored internally• fertilization is externalfertilization is external• fert. eggs carried (usually by females)fert. eggs carried (usually by females) until hatchinguntil hatching• more common in invertebrates more common in invertebrates
External
Brooders
• parental care of juveniles after hatchingparental care of juveniles after hatching does occur but is rare, mostly in fishesdoes occur but is rare, mostly in fishes
Cardinal FishCardinal Fish
Asexual Reproduction
• Occurs via splitting, budding or fragmentationOccurs via splitting, budding or fragmentation
• Generally rare, but more common in colonial organism at Generally rare, but more common in colonial organism at the cellular level of organizationthe cellular level of organization
DispersalDispersal
egg >> larvae >> juveniles >> adultsegg >> larvae >> juveniles >> adults
•Most marine organisms have a larval stageMost marine organisms have a larval stage
DispersalDispersal
• Why the difference?Why the difference?
egg >> larvae >> juveniles >> adultsegg >> larvae >> juveniles >> adults
•Most marine organisms have a larval stageMost marine organisms have a larval stage
•Most freshwater organisms do notMost freshwater organisms do not
DispersalDispersal
DispersalDispersal
DispersalDispersal
Development - LarvaeDevelopment - Larvae
Hatch – egg to larvaeHatch – egg to larvae
• notnot tied to specific developmental stage tied to specific developmental stage
• water temp and oxygen contentwater temp and oxygen content
• tide conditions, time of day, seasonal current tide conditions, time of day, seasonal current changes changes
Coral Reef Flat DamselfishCoral Reef Flat Damselfish
Hatching occurs at sunset of night of Hatching occurs at sunset of night of strongest ebb tidestrongest ebb tide
Larval stageLarval stage
Duration of larval stage dependant on Duration of larval stage dependant on resource needs in relation to currentsresource needs in relation to currents
• Food, habitatFood, habitat• 1 week to 18 months1 week to 18 months
Larval stageLarval stage• Two main typesTwo main types1)1) Lecithotrophic –with yolk sac, no Lecithotrophic –with yolk sac, no digestiondigestion2)2) Planktotrophic – feed while larvae, Planktotrophic – feed while larvae, digestiondigestion• Name different across taxonomic groupsName different across taxonomic groups
1)1) Zoea – CrustaceansZoea – Crustaceans
2)2) Amphiblastula - spongesAmphiblastula - sponges
3)3) Veliger – some molluscsVeliger – some molluscs
4)4) Leptocephalus – some fishesLeptocephalus – some fishes
5)5) Hard corals - planulaHard corals - planula
Larva – unknown for many speciesLarva – unknown for many species
Migration – a directed movementMigration – a directed movement
Migration – a directed movementMigration – a directed movement
Migration – a directed movementMigration – a directed movement
Migration – a directed movementMigration – a directed movement