CARIBBEAN CORAL REEF BIOLOGY AND
a) segment A, 0:00 – 1:51
1. What forms the massive structure that is the base of this Caribbean modern coral reef?
*Limestone & calcium carbonate skeleton produced by corals
2. What are the conditions under which corals in the reef grow best?
*Shallow, tropical waters. Temp warm, nutrients scarce, sedimentation rates low
3. Why do coral morphologies differ on a reef?
*In response to wave strength, sedimentation and amount of sunlight.
4. Where in the reef are flat corals found?
*Deeper parts (fore reef), ideal for collecting sunlight
5. Where are massive and branching corals found?
*Back reef, where light is abundant and sedimentation is high
b) segment B, 2:50 – 3:24
1. What is the benefit of a coral having a massive or branching shape?
*Allows sediments to be removed more easily.
2. Where are encrusting corals found? Why can they survive there?
*Encrusting corals can cement themselves tightly to reef to withstand breaking waves in
Hawaii: Hawaiian Hoary Bat, only native land mammal endemic to Hawaiian Islands
Video Study Questions:
1. How far are the Galapagos Islands from the South American mainland?
2. What enabled the iguanas to diverge once they reached the Galapagos Islands?
*The fact that there were several islands. Allopatric speciation (geographic
isolation then genetic isolation)
3. Which type of iguanas first colonized the Galapagos Islands? *Land iguana
4. How did the original iguanas who colonized the Islands get there?
*Floated across on a fallen tree
Both the marine and land iguanas of Galápagos resemble land iguanas found on the
South American mainland, about 600 miles to the east. Accident sent them to
Galapagos. Thereafter, the fact that there were several different islands in the
archipelago enabled them to diverge. The marine iguana, which is found nowhere but
on Galápagos, presumably evolved on one island only at first, then later spread to the
other islands, where they later diverged into all the different varieties that are now
This is a land iguana. It was land iguanas that first colonized the Galápagos Islands and
then evolved separately into the modern land iguanas here and the marine iguanas, on
the separate islands. The original colonizers would have been land iguanas that floated
across, probably on maybe a fallen tree or something like that, perhaps in a hurricane.
This has been known to happen in the West Indies, it's actually been recorded: Fallen
trees in a very, very high wind, blown across from