Coral Life Cycle - Dr. Hunter PDF

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Dr. Hunter...

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Brooders typically reproduce throughout the year Broadcaster typically have a different schedule (mass spawning) Asexual Reproduction in Corals: ● Fragmentation - small fragment breaks off ● Budding of polyps ● Polyp bail-out - soft tissue polyp leaves parental skeleton and forms its own new one ● Parthenogenetic production of larvae - identical genotype of female (no fertilization) Ancanthocaulus → growths on bottom of coral; can break off and grow on their own Polyp Bailout / Expulsion: ● New polyp is popped out and can settle down on its own as a planula, but it came from an adult colony ● Identical genotype to the parent

Porites compressa - branching made for asexual reproduction Boring organisms

Comparing Color of Corals to Look at Genotypes: ● Graph 2 groups of corals together ● Corals that are the same genotype fuse together ● Corals with different genotypes show a repulsion ● This shows that corals can identify clone mates Coral Growth: ● Asexual reproduction ● Intra Tentacular Budding → oral discs divide, producing same sized polyps ● Extra Tentacular Budding → from coenenchyme, producing a smaller polyp

Coral Growth Rates: ● Negligible to 25 cm/year (Acropora spp.) ● Porites compressa in Kaneohe Bay → 3.5 cm/year ● Massive Porites spp. → 1 cm/year

Birkeland Challenge: ● Largest known coral colony → Ta’u American Samoa ● 7m tall and 41m circumference ● 200 million polyps

Intra Tentacular Budding Familiar with: Calyx, Corallite, Corallum (entire colony), Columella (upright post in middle of calyx) - CL, Costa (CS), Septa (S), Coenosteum, Dissepiments, and Wall

Calice: cup-shaped depression on corallite surface Coenosteum: skeleton UP SLIDE FO

Continuous and Discontinuous Costae (usually in multiples of 6) Measurement of Growth: ● Bag over colony of interest and a rubber band around the base ● Through bag, you manipulate eppendorf tube and into staining chamber ● Leave for day → calcification takes place ● Measurement the growth from the stain Upward growth of polyps is on lunar cycle Under UV light, can see luminescent lines due to annual rainfall and temperature

Coral growth impacted by latitude Darwin Point: ● 28N latitude ● Between zone 2 and 3...