Critical Life History Stages in Marine Invertebrates Flashcards
Briefly describe the two different modes of asexual reproduction
Vegetative:common forms
–Fission of individuals: Anthozoans
- longitudinal fission
- Stay attached to the colony
Fragmentation
•Acropora sp. (coral)
Parthenogenesis: rare
–Pocilloporadarmicornis: Coral
–Egg -> Planulalarva
–100 day dispersal
What are the pros and cons of asexual reproduction?
Advantages of vegetative reproduction:
Spread of successful genotype eg corals
Better success at collecting food
Disadvantages of vegetative reproduction:
Changing environment
But Corals can switch to sexual reproduction: competition, changes in environment
What are the modes of sexual reproduction?
- Separate Sexes
- Hermaphrodites
-Simultaneous
-Sequential
- Protogynus
- Protandrous
Briefly describe larval disperasal and its advantages and disadvantages
External fertilizers: dispersal inevitable
–Sessile
Mobile, Internal fertilizers
–Snails, veligerlarvae
Advantages of larval dispersal:
–rapid colonization of open habitat
–reduced competition with adults
Disadvantages:
–Dispersal to inappropriate habitat
–Gene flow limits local adaptation
What are the different modes of dispersing larvae?
Planktotrophic(common, long phase, feed in plankton, eg crustacea)
Lecithotrophic( medium phase, ‘yolk’, some benthic inverts eg ascidians)
Direct (v. short larval phase if any, eg snails).
How does the pelagic larvae phase make sense?
Long Planktonic dispersal (biphasic):
Breaks parasite cycles
Dispersion
Avoid predators
Different food sources to adults
What is the value of brooding as a strategy?
Direct Release:
increase survival likelihood
reduces dispersal distance
Who Broods?
–smaller bodied invertebrates
–Colonial (modular) animals
Why Brood?
–unpredictable habitat/patchy
Why is there so much interest in researching sponges these days?
Vast amount of bioactive compounds and materials
What is the craziest sponge?
Polymestia sp.
the first surfers
Why are sponges so valuable and well worth researching?
The oldest multicellular assemblages occur in the sea, eliciting substantial chemical diversity with modes of action relevant to humans use
- a renewable source of discovery for high quality biomedicinal leads, and materials
- Opportunity exists for production of probes, tools and other products with strong potential for multiple product industry.
- Aquaculture has a role for providing sustainable immediate supply of scaffolds and possibly in economic production of new marine products
- Harnessing natural reproductive attributes of metazoans and using chemical ecology triggers can optimize yields…..
