PRACTICAL Flashcards
(58 cards)
Define a coral reef
A coral reef is a massive deposit of calcium carbonate by colonial stony corals and other organisms, it is a large cohabitation of many organisms. It has a skeleton and other building organisms that hold and maintain it.
How does a coral reef form?
It is hermatypic so it lives within itself. Cnidaria build reefs by forming the skeletons and colonial polyps are connected together via tissue. Anything that fixes calcium carbonate can form reefs.
Two key developments from the Cambrian explosion in the ocean
Ocean acidification and an evolutionary arms race
Zooxanthellae
A photosynthetic algal cell that contributes organics to corals and allows it to grow faster (carbon source)
What leads to bleaching
Corals spit out zooxanthellae when it is too hot, and the absence of the zooxanthellae leads to bleaching
Conditions that support reef formation
Relatively stable or warm temperatures, light availability, high salinity, limited sedimentation, mid range wave action and limited air exposure
Florida platform reef formation
The platform has either been completely covered or above water over 20,000 years
Fringing reefs
Near shore with a narrow band of coral, has a beach(usually sandy or mangroves), a reef flat (seagrass interspersed with small corals), a reef crest (corals exposed at low tides) and a reef slope (as depth increases species composition changes).
Barrier reefs
Off shore and separated from land by a deep lagoon, have a lot of regions with coral. The reef crest is where the coral meets the surface.
Atoll Reefs
Formed by the subsidence of an island, a fringing reef that keeps growing, occurs far from mainlands and often healthier
Patch reefs
Shallow water, large halos of sand around the patches of coral
Spur and groove reefs
Large crests of coral interspersed with sandy channels, occurs with wave action
Porifera
Sponges, have no tissues or organs and a simple cellular matrix. Have calcium carbonate structures and other numerous types of cells
Porifera reproduction
Sperm take in through the ostium for internal fertilization, zygotes develop and released as larvae. The larvae swim around using cilia, undergo metamorphosis and sink to the bottom
Cnidaria
Are diploblastic and have cnidocytes(stinging cell), corals, anemones, and jellyfish secrete calcium carbonate
Hard coral name
Sceractinian
Soft coral name
Gorgonians
Cnidaria life cycle
Stalked polyp to free floating medusa and form separate male and female medusa, the sperm and egg from the medusa become ciliated free floating larvae, and the larva settles and grows into the polyp
Annelida
Triploblastic, protostome. Characterized by segmentation and a cuticle covered with setae (little hairs or bristles). They have a calcium carbonate shell, they are worms that contract. Mobile larvae (lophotrochozoans)
Mollusca
Triploblastic, protostome. They have a radula or a scraping tongue and mobile larvae (lophotrochozoan)
Octopus, squid, clams, oysters, mussels, scallops, snails, slugs, chitons
Platyhelminthes
Triplolastic, protostome, lophotrochozoans and flatworms.
Nematoda
Triploblastic, protostome that molts, has an exoskeleton so it slithers when it moves
Arthropoda
Triploblastic, protostome, molts, segmentation of jointed appendages, complete exoskeleton make of calcium carbonate. Insects, mites, crustaceans and spiders
Echinodermata
Triploblastic, deuterostomes that use calcium carbonate. Marine only and characterized by symmetry. Starfish, brittle star, sea urchins, sand dollars, sea cucumbers, feather stars and sea lillies. Has ossicles
