Objectives of the Coral Reef Cart Collection

Coral Biology¹

Corals are cnidarians (also known as coelenterates), and are related to hydroids, jellyfish, box jellies, and sea anemones. Corals in these tanks include:

• 
  Hexacorallia – the hard (stony) corals are perhaps the best-known group, as they secrete calcium carbonate skeletons and are the reef-builders. They have six tentacles (or multiples of six).
  
• 
  Octocorals - the soft corals have eight tentacles and lack an external skeleton, having instead internal skeletons consisting of separate, unfused spicules of calcium carbonate within their tissues or with axes of a dark protein called gorgonin.
  
• 
  Hydrocorals – these include the fire or stinging, corals. They are not true corals (they occupy a different class “Hydrozoa”). Although they look like real corals, they are more closely related to jellyfish and other stinging anemones.
  

Cnidarians are characterized by having alternating lifestyles, existing either as a polyp, the sessile attached stage, or as a medusa, the free-floating jellyfish-like stage.

• 
  Most corals are colonial, often living in communities of astonishing numbers of individuals, though a few forms, such as the mushroom coral, are solitary.
  
• 
  All corals have supporting structures, formed of calcium carbonate or of a fibrous protein or both.
  

The coral polyp is a relatively simple organism with a hollow, cylindrical structure, its bottom end attached to its skeleton in the case of stony corals, or in the case of octocorals, to the substrate. At the upper end is a single opening surrounded by tentacles armed with specialized stinging structures, called nematocysts, used to paralyze prey. This opening functions both as mouth and anus, ingesting food and excreting waste.

• 
  Coral shapes and sizes vary greatly among species.
  
• 
  General appearance varies from boulder-like spheres of brain coral to the branching staghorn, and beyond that to the plate-like elkhorn.
  
• 
  Soft corals are more flexible, often waving gracefully in the currents.
  
• 
  Morphology is often affected by depth, and exposure to light and currents.
  

Mutualistic Relationship: zooxanthellae

In the photic zone, light penetrates to fuel the photosynthesis of symbiotic algae, a species of dinoflagellates collectively called zooxanthellae, that live within the corals’ tissue. The relationship between coral and algae is mutualistic, benefiting both partners and is the driving force behind the productivity of the reef system.

• 
  Corals provide zooxanthellae with protected living space and nutrients necessary for photosynthesis.
  
• 
  A significant part of coral nutrition is provided by their algal symbionts that produce sugars and amino acids used by the coral to manufacture the proteins and complex carbohydrates to fuel its activities.
  
• 
  The algae are so productive that up to 90% of the organic material they manufacture is available to and used by their coral hosts
  
• 
  The algae enrich the waters of the reef with oxygen, their photosynthetic by-product.
  

The health of stony corals and their ability to secrete sufficient CaCO₃ is dependent on the energy produced by their tiny partners. The very existence of coral reefs relies on this relationship.
Much of the color of reef corals is usually created not by the coral itself, but by the various species of zooxanthellae, which typically range from yellow, to brown, and green. The few species with bright colors such as red, orange and yellow generally do not harbor zooxanthellae.
All hard corals, fire corals, and many octocorals maintain this symbiotic relationship.

Coral Reproduction

Sexual reproduction

• 
  During sexual reproduction, some species produce eggs that are fertilized internally and brooded either inside or outside the parent.
  
• 
  Many species broadcast both eggs and sperm, usually with timing synchronized within the entire colony or even with reefs in the general vicinity, to ensure cross-fertilization. Planktonic larvae are then dispersed in the currents, and the few that survive predation and other misfortune develop into the polyp stage if they successfully settle on a suitable reef or other substrate.
  

Asexual reproduction

• 
  Corals also reproduce by budding. When it reaches a certain size, the parent polyp divides, producing a clone that expands the original colony or begins a new colony.
  
• 
  Because of clonal reproduction, many individuals in a coral community are genetically identical, a condition that persists over long periods of time.
  

Coral Reef Collection Specimens

Porifera

Venus flower basket sponge

Sponge from Jamaica

Misc. sponge

Cnidarians: Octocorallia (soft corals)

Common sea fan

Misc. Gorgonia

Cnidarians: Hexacorallia (hard corals)

Brain coral

Mushroom coral

Pocillopora

Turbinaria reniformis

Mollusks: Gastropods

Misc.cone snail

Tiger cowrie shell

Misc. murex shell

Triton’s trumpet

Mollusks: Bivalves

Tridacna clam (ruffled?)

Mollusks: Cephalopods

Cuttlefish bone and

dwarf cuttlefish bones

Full nautilus shell and

sliced nautilus shells

Octopus’ beak

Arthropods

Hermit crabs

Echinoderms: Sea Stars

Blue linkia sea star

Chocolate chip sea star

Echinoderms: Urchins

Pencil urchin

Misc. test (?)

Vertebrates: Cartilaginous Fishes

Ray barbs

Sand shark jaw

Vertebrates: Bony Fishes

Parrotfish lower jaw

Porcupine fish spines

Porcupinefish

Triggerfish skull

Triggerfish skeleton

Seahorses

Directory: 2008
2008 -> Exam 1 of Computer Networks (ice 1230) 2008 7
2008 -> Program description
2008 -> Curriculum Vitae Museok Song
2008 -> Word Wall Chants Use these as fun ways to practice word wall words at home!
2008 -> Rockettothesky
2008 -> "Unique " "dfo " "Glide " "Country" "Other" "Nations" "X. Affected" "Locations" "Rivers" "Began" "Ended" "Days" "Dead" "Displaced" "Damage usd." "Main cause" "Severity " "Affected sq km" "Magnitude m " "Notes and
2008 -> The environment in the news
2008 -> Virginia High School League Scholastic Bowl page 2007-08 District Competition Match #46
2008 -> Missouri State High School Activities Association Match #12 2007-08 Conference & Tournament Competitions page
2008 -> Louisiana state university health science center new orleans emergency medicine residency program policies to supplement lsuhsc house officer manual

Download 211.7 Kb.

Share with your friends: