Part Two   Part Three   Part Four   Part Five   Part Six   Part Seven

  PHOTOSYNTHESIS AND THE REEF AQUARIUM - Carbon sources, Looks at photosynthesis in reef aquaria from a chemical perspective.

   Corals optical ability ?  -  " In many species of symbiotic corals, spawning occurs synchronously several nights after the full moon. This process is correlated with the level of lunar irradiance, but the mechanism by which these cnidarian/zooxanthellate symbioses can detect such low levels of light remains unknown. Here we report the first biophysical evidence that the host animal exhibits extraordinarily sensitive photoreception in the blue region of the spectrum. Using a high-resolution laser-induced signal to detect tentacle scattering, we measured the effect of low irradiance on the contraction of polyps in the corals that normally have their tentacles extended in darkness. Similar to most deep-sea invertebrates, the action spectra of coral photoreception reveal a maximum sensitivity in the blue, at 480 nm, with a spectral band width (at full-width half-maximum) of ca. 110 nm. The spectra closely overlap the maximal transparency of oligotrophic tropical waters, thus optimizing the perception of low light at depth. The detected threshold of photoreception sensitivity is ~1.2 x $10^{15}$ quanta $m^{-2}\,s^{-1}$ in the blue region. This makes corals capable of sensing the blue portion of lunar irradiance, as evidenced from the recorded slight contractions of polyp tentacles under variations in moonlight intensity."







  Most corals are Broadcast spawners releasing gametes once a year, sometimes twice a year. Such spawning events usualy occur over the coarse of a few nights. A small minority of corals are brooders, releasing their planulae monthly or every few months.

  SEXUAL REPRODUCTION - The release of eggs / sperm into the ocean's currents as shown in the above graph.

   Shown below is my Pavona sp. releasing sperm.
     

  Common Asexual Reproductive methods:

 Longitudinal Division: This is where the coral divides into approximately equal halves, thirds, quarters, etc, like when a pizza is cut. Each piece has part of the oral (mouth) and basal (foot) disc then heals up and forms a new coral, typically moving away from the other corals.

 Budding: This is where the parent polyp will form a slight projection somewhere on its body and a new polyp will form at this point. The new polyp, called the daughter polyp, will either stay attached to the parent polyp or detach from the parent polyp and grow into a new coral.

 Pedal Laceration: This is where a portion of the basal disc will detach from the parent polyp. Then either the parent polyp moves away (most common) or the portion of the basal disc will move away. Eventually the fragment of the basal disc will grow into a new coral.

 Stolon Growth: A "runner" is sent out from the base of an existing polyp. As this runner (called a stolon) grows, it begins to form new polyps along its length. The stolon can be very thin, sometimes breaking in pieces, or it can develop into a thick mat, depending upon the species. This is seen most commonly in zoanthids.

 Transversal Division: This is where the coral will split along a horizontal line between the base of the coral and the top of the coral. The oral disc will be carried away by water currents and if it survives it will attach and grow a new foot. The basal disc will simply regrow a new oral disc and mouth. This is most commonly seen in Actinodiscus sp. mushrooms.

Fragmentation: This is where a portion of the coral is deliberately released by the parent colony (as opposed to a wave breaking a coral in nature or a careless hand breaking a coral apart in our tanks) and attaches in a new location to form a new coral. This is commonly seen in Capnella sp. or other similarly structured soft corals.

Self-Fertilization: This is when a male polyp releases sperm into the water and that sperm fertilizes an egg from a female polyp in the same coral colony.


  POLYP BALL FORMATION - First reported in a Goniopora species where the colony forms little miniature versions of itself, complete with skeletal mass and drops them. The photos below are of my Goniopora species doing the same.

       


  THE PRESENCE OF GONADOROPIN-RELEASING HORMONES - The objectives of this study were to investigate the presence of immunoreactive GnRH (irGnRH) in scleractinian coral, Euphyllia ancora, study its seasonal variation, and evaluate its biological activity.

  TROPICAL CORAL REEF ENVIRONMENT RHYTHMICITY AND TECHNIQUES FOR INDUCING CAPTIVE CORAL SPAWNING  -  " Modern captive coral reef aquaria ecosystems have attained the capability for supporting the long term healthy maintenance of many tropical reef corals. The stimulation of asexual reproduction has also occurred for many species and captive propagation is proceeding slowly. "

  For those interested, and you should be, in having corals reproduce within an aquarium setting, the best chance we have of being successful is by keeping those species that reproduce by planulae brooding, this is where the corals eggs are fertilized internaly, forming planulae (coral larvae) which are then released.
  This type of reproduction gives us the best chance at having corals reach settlement and form new colonies.  Below is a list of coral species that are known to be brooders as provided by Eric Borneman.


  Agaricia agaricites, Agaricia fragilis, Agaricia humilis, Agaricia tenuifolia, Alveopora daedalea, Alveopora japonica, Astroides calycularis, Balanophyllia elegans, Balanophyllia europaea, Balanophyllia regia, Caryophyllia cyathus, Cladopsammia rolandi, Cyphastrea ocellina, Euphyllia glabrescens, Euphyllia rugosa = glabrescens?, Eusmilia fastigiata, Favia fragum, Favia gravida, Flabellum curvatum, Flabellum impensum, Flabellum thouarsii, Galaxea horrescens, Goniastrea aspera, Goniopora decima, Heliofungia actiniformis, Isophyllia sinuosa, Isopora brueggemanni, Isopora cuneata, Isopora palifera, Leptopsammia pruvoti, Letepsammia formosissima, Madracis formosa, Madracis mirabilis, Madracis myriaster, Madracis pharensis, Madracis senaria, Manicina areolata, Monomyces rubrum, Mycetophyllia ferox, Pocillopora damicornis, Porites astreoides, Porites furcata, Porites heronensis, Porites murrayensis, Porites panamensis, Porites porites, Porites sillimaniani, Porites stephensoni, Rhizopsammia minuta, Scolymia wellsii, Seriatopora caliendrum, Seriatopora hystrix, Siderastrea radians, Siderastrea stellata, Stylaraea punctata, Stylophora pistillata, Trochopsammia togata, Tubastrea aurea, Tubastrea coccinea, Tubastrea diaphana, Tubastrea faulkneri.