Start of the notes for the second exam

Discussion:

Corals Variability - Keynote pdf

Corals

Corals are in the Kingdom Animalia, Phylum Cnidaria.
Examples of other cnidaria are anemones, soft coral, box jellies, Portuguese man-of-war, and zoanthids.

Cnidaria characteristic:

• Stinging cells
• Radially symmetric
• Outer epidermis, middle jelly-like tissue, and gastrodermis
• Only one body cavity
• No head, central nervous system, nor formal excretory, circulatory, or respiratory systems

Reef-building corals (or stony corals) are hermatypic corals .
Corals are colonial organisms.
The basic body unit of an individual coral is a polyp.

Corals reproduce primary by cloning, therefore, a coral head is a colony of individual, yet genetically identical polyps.

Corals secrete a hard exoskeleton composed of a calcium carbonate (CaCO₃) mineral called aragonite.
Polyps make a small cup called a calyx.
When stressed, a polyp contracts into its calyx.

Corals have a symbiotic relationship with a photosynthetic, unicellular algae: zooxanthellae.
The relationship is mutualistic because each derives a benefit.
Endosymbionts provide most of the energy for the coral host.
And the corals provide housing and nutrients to the zooxanthellae.

Examples of Hawai'i corals:

• Lobate: example - Porites lobata
• Branching: example - Pocillopora
• Finger: example - Porites compressa
• Mushroom: example - Fungia scutaria
• Laminar: example - Porites rus

The notes for the second exam are continued in Beaches