Coral Reefs!

 Phylum Cnidaria and the class Anthozoa  There are over 800 known Hermatipic species ◦ Hermatipic- reef building  Coral reefs are the most biologically diverse ecosystems on earth, ◦ Source of food ◦ Protect coastlines (from storms and erosion) ◦ Gives homes and spawning and nursery grounds for fish ◦ Provide jobs to local economies from fishing, recreation, and tourism ◦ New medicines

◦ Also known as ahermatypic (non reef building) coral, they do not produce a calcium carbonate skeleton ◦ Often called octocorals ◦ Mostly colonial ◦ Contains sclerites in cells on the outside of the colony found in coenenchyme, (jelly- like tissue) between polyps.  Sclerites made of protein and calcium carbonate. ◦ Some are also encrusting

 Hermatipic- Reef building coral ◦ Contains a basal plate ◦ Net benefit of the world's coral reef ecosystems estimated to be $29.8 billion per year ◦ Have zooxanthellae  Deep water and some cold water corals lack zooxanthellae ◦ Most corals feed at night  Similar to sea anemones. Polyps extend their tentacles to capture prey, first stinging them with toxic nematocyst cells, then drawing them toward their mouths.  Also collect fine particles in mucous film which are drawn by cilia into the polyp's mouth. Some species are entirely mucous suspension feeders  Prey ranges in size from small fish to zooplankton, depending on size of the coral

◦ Deep sea corals live on in deeper water from 50 m to over 3,000 m ◦ A few species also live in shallower, cold water in the northern latitudes. ◦ Found in all oceans ◦ Like their shallow-dwelling relatives, deep-sea corals exhibit high biodiversity. ◦ Don’t contain zooxanthellae (no light) ◦ Don’t know the extent of communities because they live so deep  UbaVZRIS18 UbaVZRIS18

◦ an algae that gives off oxygen and other nutrients ◦ polyp gives the algae carbon dioxide  That is why coral reefs grow near the surface ◦ Algae enhance the coral’s ability to synthesize calcium carbonate  Coral Bleaching ◦ When algae leave, due to warmer than usual water or a change in pH  EdoizgeNJk EdoizgeNJk  0jof35WuAo 0jof35WuAo

 Feed similar to sea anemones. Polyps extend their tentacles to capture prey, stinging them with nematocyst cells, then drawing them toward their mouths.  Also collect fine particles in mucous film which are drawn by cilia into the polyp's mouth. Some species are entirely mucous suspension feeders  Prey ranges in size from small fish to zooplankton, depending on size of the coral

Can be either asexual or sexual  Budding- asexual ◦ new polyps bud off from parent. This occurs when the parent polyp reaches a certain size and divides. Continues throughout the animal's life and produces polyps identical to the parent polyp.  Fragmentation- asexual ◦ Allows a portion of an entire colony to establish a new colony. The separated individuals start new coral colonies that are genetically identical to the parent colony

 Broadcast Spawning ◦ 3/4ths of all stony coral species are broadcast spawners ◦ Produce male and/or female gametes that are released into the water in large numbers  Allows them to spread their “children” over a broad area.  Have lots of kids at one time to compensate for how many die a terrible depressing death, while their parents watch, and cant do anything about it.  occurs as a synchronized event, very important because male and female corals cannot move.  Usually occurs in response to environmental cues.  Long-term cues may be related to temperature, day length, or rate of temperature change.  The short-term control is usually based on lunar cues  

 Remaining 1/3 of coral species are brooders ◦ Only male gametes released into water. ◦ The gametes are negatively buoyant and transported by waves and current before sinking ◦ They are taken in by female coral polyps containing egg cells fertilization occurs inside the female coral and produces a small planula. ◦ The planula is released through mouth of female when it is old enough to settle very soon after its release.

 Overtopping ◦ used mostly by fast growing species ◦ The faster growing coral just grows over the other coral ◦ The covered coral gets less light and food.  Aggression ◦ involves extruded digestive filaments and sweeper tentacles. Typically results in the death of some of the other’s polyps.  topics/wild-animals/coral-nighttime- battle.htm topics/wild-animals/coral-nighttime- battle.htm

◦ Cells are specialized to perform various functions ◦ Very limited organ development ◦ Have a simple stomach (gastrovascular cavity ) opens only on one end, and a ring of tentacles. ◦ No central nervous system. ◦ While appearing to be a single organism, many coral are actually a colony of many individual, identical, coral polyps. ◦ Are only a few millimeters in diameter

◦ The polyps of hard corals sit in a calyx that is produced by the coral with calcium carbonate ◦ The walls surrounding the calyx are called the theca and the bottom is the basal plate. ◦ Basal plate is a calciferous ring with six supporting ridges. The ridges grow vertically and project into the base of the polyp. ◦ Tabulae are horizontal partitions that allow for upward growth by isolating the surface from the skeleton.