The Wonderful World of Pulsing Xenia "pumping" Xenia Corals

Xenia Corals

 

The Wonderful World of Pulsing Xenia "pumping" Xenia Corals 

Click here for a Pulsing Xenia of your own!

Xenia corals are a beautiful and tranquil species of "soft" coral. The opening and closing of the polyps in a pulsing or pumping action is what gives this coral the constant look of gently flowing and waving in the water. In Xenia Corals, groups of stalks ending in these feathery polyps can spread into large mats, and pulsing xenia are quite popular amongst marine reef enthusiasts.

Lighting And Water Current

Xenia corals require an environment that includes moderate to strong lighting. Usually brighter is better for xenia corals living in a marine aquarium, although some success has been reported at lower light levels. They also require at least moderate water flow, as they are one of few corals that seem to do well right up against the strong output of a powerhead.

Description

Xenia corals have sturdy stalks up to 3" long, which are usually tan in color. The end of each stalk is covered with a crown of feather-like polyps, each carried on a 1"-2" stem. Those polyps pulsate open and closed in a pumping motion. Groups of these stalks form colonies that can grow into large mats.

Hardiness

As far as hardiness is concerned, xenia corals pose an interesting case. While some hobbyists cannot keep this type of coral alive, other hobbyists report that they are almost like a fast growing "weed" coral. Although there are guidelines that can be followed as to xenia care in the home aquarium, no one seems to fully understand what will guarantee the success of this type of xenia corals on the reef.

  Aggressiveness And Feeding

Xenia corals have an extremely low aggression level. They do not possess any apparent stinging capability, but they do tend to grow over and shadow other corals if allowed. Xenia corals are photosynthetic and do not accept any known foods if offered in the aquarium. It is believed that they can absorb some nutrients directly from the water. Xenia may do better in tanks that are not frequently skimmed.

Found this great video showing the pulsing movements of a Xenia compliments of Michael Rice:

Corals Reproduction

Xenia corals reproduce in the tank by attaching its stalk against adjacent surfaces and splitting into two colonies. With this phenomenon, the colonies tend to "walk" in the direction that the water movement bends their stalks. They can usually be coaxed to grow up the back glass of an aquarium.

Click here for a Pulsing Xenia of your own!

Open Brain Surgery Anyone? oops! I mean Open Brain Coral!

Click here to add an Open Brain Coral to your Tank!

Quick Facts :: Open Brain Coral Care Level: Moderate Waterflow: Medium Placement: Bottom Lighting: Medium to High Temperament: Semi-aggressive Color Form: Green, Red, Pink, Brown Supplements: Calcium, Strontium, Trace Elements Water Conditions: 72-78� F, dKH 8-12, sg 1.020-1.025, pH 8.1-8.4 Origin: Indo-Pacific Family: Trachyphylliidae Species: LPS Hard Corals Category: LPS Hard Corals
Open Brain Coral Aquarium Care, Lighting Requirements and Feeding Information The Open Brain Coral is a Large Polyp Stony (LPS) coral, sometimes referred to as the Pacific Rose Coral, or Wellsophyllia/Trachyphyllia Brain Coral. They are not connected to the substrate and can be easily collected from the reef when mature. They are often found in varying shades of metallic green and are characterized by their irregular round shape, deep impressions and fused walls with numerous folds. Originally these species were identified as Wellsophyllia corals being separate from Trachyphyllia corals. This distinction is less commonly used now, and the Wellsophyllia Brain Coral is often referred to now as a Trachyphyllia radiata coral, thus making the two interchangeable. All of their characteristics including feeding, lighting and water movement requirements are identical. Wellsophyllia/Trachyphyllia Brain Corals do best in a well established reef aquarium that incorporates moderate to strong lighting and a moderate water current within the aquarium, along with the addition of calcium, strontium, and other trace elements to the water. These corals prefer to be placed on a sandy substrate, with plenty of space between it and other corals, as it is sensitive to stings from its neighbors. It is advisable to locate these corals someplace on the reef that will keep them well separated from all neighbors and even provide some extra space to roam. Wellsophyllia/Trachyphyllia Brain Corals utilize the symbiotic algae zooxanthellae from which it receives the majority of its nutrition through photosynthesis. They also benefit from occasional feedings of meaty items, like shrimp, clam and squid. They should only be offered food when the tentacles are fully expanded, which is typically during the night time hours. An In Depth look:   Brain Coral Care Beginner and experienced reef enthusiasts alike will choose to keep brain coral in their home tanks and aquariums, as brain coral care is generally simple and adaptive to many environments. Overall, the nature of the brain coral is extremely hardy, which makes brain coral care less restrictive and time consuming than other types of coral. In The Reef Aquarium The ideal parameters for brain coral care include clean water conditions, moderate lighting and water flow, sufficient space between other specimens in the tank, and including trace elements such as calcium and strontium periodically in the water. The exact color of the brain coral may determine the strength of lighting used in the tank- keep this in mind for overall brain coral care. Setting the temperature in the artificial tank will also help keep the brain coral care in optimal health- the water temperature should fall between 75 and 84 degrees. Substrate Since brain coral is a sand dwelling organism, having a tank that is lined with sand, gravel or a mud filled bottom is a crucial element of brain coral care. If brain coral care does not include a substrate lined tank, the brain coral will not be able to use their extended flesh to propel themselves towards optimal lighting and water conditions. Because brain coral does utilize a defense mechanism of stinging rays, adequate brain coral care will depend on having its own established place in the tank so the coral doesnt sting nearby creatures. Care And Diet Because brain coral contains photosynthetic algae in its tissue, brain coral care does not depend on supplemental feedings. However, brain coral care can include filter feeding food (that is used for invertebrates) in addition to various micro plankton, fish flesh, shellfish or crustaceans. If your brain coral care does include supplemental feedings, the coral should be fed no more than twice a week- and only when the brain coral is open (usually at night). Propagating Specimens Part of brain coral care does include the option of cultivating the coral in a home aquarium or reef tank. Because the brain coral reproduce asexually through fragmentation in the wild, the process can be mimicked during brain coral care in an artificial environment. Overall Health You should be vigilant about maintaining your corals- proper brain coral care includes making regular assessments of the corals health. Warning signs to look for when doing brain coral care assessments include bleaching, tissue becoming detached from the corals skeletal system, and the how regularly the polyps extend, in addition to how much they extend. Most likely you will need to adjust the water quality of the tank if these things are found during overall brain coral care. Another possibility is aggression from a neighboring specimen which may threaten develop of the brain coral.

Click here to add an Open Brain Coral to your Tank!

Mantis Shrimp with thier "Alien-like" visual system

 Ever notice how strange the Mantis Shrimps eyes are?  Things just recently got a bit more strange for these little guys.  A new study conducted by Michael Bok at the University of Maryland indicates that mantis shrimp use amino acids that are normally found as a natural sunscreen in animal skin in order to see UV light.  

Mantis shrimp who are known by some aquarists to crack aquarium glass with their mighty claw  are also now set up with an impressive visual system.  Ultra violet light, which is not on the wavelength scale that the human eye can see, these crabs can see the orientation or polarizations of light waves.

Mantis shrimp have filters within their eyes that absorb UV light. Bok discovered that these filters are made out of mycosporine-like amino acids (MAAs), which typically absorb harmful ultraviolet light in animal skin. The MAAs in mantis shrimp eyes instead absorb different parts of light, allowing them to discern UV light.

“The overall construction of the mantis shrimp's visual system is just so unbelievably ridiculous, so this is just another piece of that tapestry,” said Bok. “It's a very, very strange system, and it’s very alien compared to ours.”

Crazy eyes

Mantis shrimp are complicated creatures. They are fierce hunters, killing prey with swift blows from their powerful claws, which can accelerate as fast as a .22-caliber bullet. Some species are monogamous, but all exhibit complex social behavior.

A close look at the complex eyes of a colorful Mantis shrimp.

Mantis shrimp vision seems to be a crucial ingredient to the animals' success. Mantis shrimp have 12 photoreceptors, compared with three in humans, and they see more wavelengths of light than humans do.

Weirdly, though, mantis shrimp don't seem to discriminate between colors with as much sensitivity as humans; a study published in January in the journal Science found that their impressive 12-photoreceptor array allows them to process color in the eye instead of in the brain. (In contrast, humans have a fairly simple eye, but lots of visual processing set up in the brain that helps us to see thousands of shades.)

Mantis shrimp photoreceptors are organized in a band in the middle of the eye, with simpler cells around them, Bok told Live Science, and they seem to scan their environment constantly.

"You can envision it as them 'coloring in the world,'" Bok said.

Filtering light

A mantis shrimp eye. A center line, called the midband, contains complex photoreceptor cells.

It was these specialized cells that interested Bok and his colleagues. They knew that five or six of a mantis shrimp's photoreceptors were used for seeing ultraviolet light, and they wanted to identify the visual pigments that made up these receptors. An initial molecular analysis of the eye of the species Neogonodactylus oerstedii, however, turned up only two pigments.

That was a bit of a surprise, Bok said. The researchers figured the mantis shrimp eye must have filters to "sort" wavelengths before they hit the visual pigments, but the scientists didn't know where to look, at first. Because UV wavelengths are invisible to humans, there would be no way to see the UV filters with the naked eye.

Fortunately, the researchers discovered that as the filters in mantis shrimp eyes absorb UV light, they emit a tiny bit of fluorescence, visible to humans.

"We were able to see these very bright, beautiful fluorescing pigments in the eye," Bok said.
The filters are made of something called MAAs, or mycosporine-like amino acids. These amino acids are common in the skin of marine organisms, and are usually used to absorb cell-damaging UV light.

Mantis shrimp, however, have repurposed the MAAs to absorb certain UV wavelengths in the eye. Each different filter removes different portions of the light, meaning that certain wavelengths only hit certain areas of the eye. 

"It pretty nicely narrows their sensitivity by removing certain components of the spectrum," Bok said. The filtering thus enables the mantis shrimp to detect multiple wavelengths with only two visual pigments.

"It's a very, very strange system, and it's very alien compared to ours," Bok said.

Bok, who is currently doing fieldwork on the Great Barrier Reef in Australia, said the next goal is to study how mantis shrimp use their unusual visual system. They might use visual information to communicate, to hunt or to avoid predators, he said.

"It's an interesting question," he said. "Why do they need this? What could it possibly be used for?"

Bok and his colleagues reported their findings July 3 2014 in the journal Current Biology.

 Original article on Live Science.