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.

**ANEMONE OF THE WEEK** Sabae Anemone

Sabae Anemones are truly a beautiful and wondrous anemone to behold.  Very elegant in look and home to many types of clownfish. 

Click Here for your Own Sabae Anemone!

Minimum Tank Size: 50 gal (189 L)
Care Level: Difficult
Temperament: Aggressive
Reef Compatible: With Caution
Lighting: High
Waterflow: Medium
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.023-1.025
Color Form: Blue, Brown, White
Supplements: Iodine, Trace Elements
Origin:  Indo-West Pacific Ocean from the Red Sea to Tuamotu
Family: Stichodactylidae

Suitable for Nano Tank: No
Tank Location:  Bottom 
 

Heteractis malu is known as the Sebae or Leather Anemone. It was previously named Radianthus keukenthali. Heteractis crispa may also be called the Sebae Anemone. Heteractis malu is usually light tan to brown in color, and may have purple tips on its tentacles.

Acclimation to aquarium life can be very difficult for this species and its care should only be attempted by the most experienced aquarists. In the aquarium it requires strong lighting, porous live rock, and a variety of sandy and rocky locations from which it can choose to live. The addition of a Clownfish, such as the Blue Striped Clown, Amphiprion chrysopterus, will immediately help with its acclimatization and improve its chances of survival. When healthy, it will become very sticky. If it grasps onto something (or someone), it will be very difficult to convince it to let go without damaging it.
Once acclimated, it should be fed a diet of fish, worms, clams, shrimp, and other meaty foods once a week.

The tentacles of the Sebae Anemone Heteractis crispa are generally whitish, violet, or greenish in color, and some specimens are found with beautiful blue, purple, and mauve tips. Usually it has a gray or violet-brown appearance overall, depending on the concentration of its symbiotic algae, zooxanthallae. It also has a rather leathery look, thus the term 'leather' in various common names. These common names are the Leathery Sea Anemone, Leather Anemone, and Leathery Sebae Sea Anemone.

In nature this anemone has been found as a host to 14 different species of clownfish. It has also been known to associate with the Domino Damselfish Dascyllus trimaculatus and anemone shrimps in the Periclimenes genus. They use their venomous cells or nematocysts found in their tentacles to sting and deflect any possible threats or attacks. Some predators can be other anemones, nudibranchs, sea stars and some angelfish. Bristle worms also have been known to irritate and chew at H. crispa.
The Sebae Anemone is the most commonly imported sea anemone. It is favored by aquarists because It will successfully host clown fish in the aquarium, though not all clowns take to all H. crispa. This anemone often doesn't do well in captivity, so it's recommended that they only be attempted by advanced aquarists.

If a healthy specimen is obtained it can do well in captivity, but Sebae Anemones are known to suffer from shipping stress and will often release their zooxanthalle in transport. Sometimes, to enhance their appeal, captive specimens are bleached out so they are also white in color. If they are white, their chances of survival are slim. The Sebae Anemone, as well as the Magnificent Anemone or Ritteri Anemone Heteractis magnifica, is often colored with vegetable or other dyes as well. Be cautious when purchasing them as these treatments can also cause the anemone problems.

Habitat: Distribution / Background

Sea Anemone Facts: The Sebae Anemone Heteractis crispa was described by Ehrenberg in 1834. The Heteractis genus is a member of the Stichodactylidae family and this genus contains about 4 species. Some names they are known for are Leathery Sea Anemone, Leather Anemone, and Leathery Sebae Sea Anemone. The Heteractis crispa is not on the IUCN Red List for endangered species.

Where are Sea Anemones Found: The Heteractis crispa is found in the Indo-West Pacific Ocean from the Red Sea to Tuamotu.

Sea Anemone Habitat: Leathery Sea Anemones are found in waters at depths of 10 to 100 feet (3-35 m). They are found deeply wedged in rock crevices with only the oral disc and tentacles visible. They are usually found with clownfish that forms a symbiotic relationship for the protection and nourishment of both animals. They use their venomous cells or nematocysts found in their tentacles to sting and deflect any possible threats or attacks, and also use them to catch prey. Some predators can be other anemones, nudibranchs, sea stars and some angelfish.
 

Description
Appearance of a Sea Anemone: The Leather Anemone Heteractis crispa has a gray or violet-brown appearance overall, depending on the concentration of its symbiotic algae, zooxanthallae. It also has a rather leathery look, thus the name. The sticky foot at the base of the pedal column is used to adhere to various surfaces. They also use the "foot" to move around if conditions are not ideal. The foot tends to be much larger than the column in comparison to other anemones. The column is generally whitish, violet, or greenish in color.

There are up to 800 tentacles on the oral disc. They can be a brownish-gray, mauve, or green; and some specimens are found with beautiful blue, purple, and mauve tips. The tentacles are very long and taper at the tip. They are so long that they typically become intertwined.
Tentacles are all over the surface of the oral disc, giving it a 'mop' appearance. The mouth in the center is often barely visible. The mouth should be closed and tight, and will open when hungry, having an oval look. A gaping mouth is a warning signal. The H. crispa takes food in and expels waste through this same opening.

Sea Anemones Life Cycles: These anemones can grow up to 12" (30 cm), but it is unknown how long they live. Some anemones can be hundreds of years old in the wild, and in captivity some have been known to last 80 years or more.

• Size of organizm - inches: 12.0 inches (30.48 cm)
• Lifespan: - It is unknown how long they live. Some anemones can be hundreds of years old in the wild, and in captivity some have been known to last 80 years or more.

Difficulty of Care

Sea Anemone Care: The Sebae Anemone can be difficult to care for because they do have high lighting needs and must be in a large enough aquarium to satisfy their ultimate size. Putting an anemone in a new tank will result in failure. The tank should be at least 1 year old and stable before adding your new H. crispa.

Sebae Anemones suffer from shipping stress, and will need dedicated care to become established in the aquarium. They need appropriate water movement and regular feeding. In fact, a lack of feeding is thought to be the second biggest reason for their demise in captivity. Feeding on an almost daily basis is a big help in keeping them alive and from moving around.

When choosing your Leathery Sebae Sea Anemone, make sure the color is good, their mouth is not gaping open, and their foot and tentacles are sticky to the touch. Also, they should be attached to something and make sure there is no damage to the foot area, often a result of pulling the anemone off its surface.
The H. crispa perish from any type of tissue damage. To take an H. crispa anemone from another aquarium, use a hair dryer. Blow at the foot of the anemone from the outside of the tank and the heat will make it pull away. If it's attached to a rock, ideally you can simply purchase the rock as well. If you cannot purchase the rock then use ice cubes in a zip lock bag, and gently rub the foot all around until it releases. This may take a few minutes, but it is the most reliable way of getting your anemone to release safely. Don't allow the fresh water of the ice cubes to touch the foot directly as this can cause tissue damage.

• Aquarium Hardiness: Difficult
• Aquarist Experience Level: Advanced

Foods and Feeding

What Do Sea Anemones Eat: The Sebae Anemone is a carnivore. In the wild, these anemones are well equipped with nutritional alternatives for their well-being. They derive daily nutrition from their symbiotic algae, zooxanthellae, which dwells within their tissues. They also use their venomous cells or nematocysts found in their tentacles to sting and capture prey. They absorb nutrients from the water around them and they consume wastes from resident animals like clownfish. It is not necessary for them to be fed by Clownfish they host, though clowns will often carry chunks of food to the anemone.
In captivity you can feed your H. crispa a mix of chopped fresh shrimp, fish and mussel from your grocery store. This variety is very good for these anemones, as they seem to derive their different dietary needs from these meats. Large anemones need food daily, medium sized anemones need to be fed 5 times a week, and the young or smaller ones need to be fed 2 to 4 times a week. The old adage that anemones should be fed once a month is false and has lead to many deaths.

Clownfish hosted with your anemone usually will not be able to sufficiently feed themselves and their anemone with the small quantity of food that is put in a captive environment. You will need to target feed this anemone. You can just offer your clowns a piece of fish flesh and they will usually snatch it out of your hand and give it to their host. However, not all clowns are this smart, so don't depend on the clown fish to feed the anemone.

• Diet Type: Carnivore
• Meaty Food: All of Diet - They can be fed a mix of chopped fresh shrimp, fish, and mussel from your grocery store.
• Feeding Frequency: Daily

Aquarium Care

Water changes of 10% bi-monthly or 20% a month are typical. Monitor your water quality for your particular situation and adjust your water changes accordingly. Keeping salinity stable with a top off mechanism is highly suggested. Keeping alkalinity at the typically acceptable range of 3.5 meq/l for reef tanks is advisable. A good protein skimmer is a must.

A Sebae Anemone 3" to 4" is equal to 2 or 3 fish as far as waste production is concerned. Purigen and Poly-fiber are great products to help in maintaining water quality. Purigen is a synthetic polymer that removes soluble and insoluble impurities from water at an exceptionally high rate and capacity, helping to control ammonia, nitrites and nitrates. Additions of Iodine and and trace elements are suggested. Control phosphates with products such as Phosban and the Phosban reactor.

• Water Changes: Bi-weekly
• Alkilinity Levels: - Keeping alkalinity at the typically acceptable range of 3.5 meq/l for reef tanks is advisable.
• Iodine Levels: - Additions of Iodine and and trace elements are suggested.

Aquarium Setup

The typical live rock/reef environment is what is needed for your H. crispa, with a sand substrate for it to settle into. Have a 4" to 8" sand bed for them to bury their foot into. The Leather Anemone will attach to a hard surface through the sand. Once it is secured it will stay put if it is happy. If it isn't happy and is moving around, be sure to check your lighting and water quality, also make sure you are feeding it adequately. With all anemones it's a good rule of thumb to have all of your pumps covered; most good quality pumps have guards on them.

Social Behaviors

All anemones are semi-aggressive because they can be mobile, although a contented Sebae Anemone will stay put once it has found a place to settle. It has often been suggested to not put anemones in a reef environment because corals cannot move away from the stinging tentacles. Once you have your anemone situated and it has not moved for several months, it might be safe to add other corals. Keep this in mind when stocking sessile inverts. Some predators can be other anemones, nudibranchs, sea stars and some angelfish. Bristle worms also have been known to irritate and chew at H. crispa.
Leathery Sea Anemones in the tank need to be at least 2-3 feet away from each other. If you have 2 anemones that are 6" across, than your tank should be at least 4-5 feet long. Anemones need to have their own space, otherwise there can be a "chemical" warfare between species. This will usually cause one to not eat, shrink, and eventually die. However, after splitting anemones will tolerate their own "clones", and sometimes their own species. Having excellent filtration and a large tank (over 100 gallons), will usually allow 2 anemones at opposite ends to thrive. You can also build a natural blockade to help prevent them from wandering into each others "space".

If you want your anemone to host clownfish, be sure it is 3 to 4 times larger in diameter than the length of the clown fish you introduce, or it will be 'loved' to death. A 4" - 6" anemone with clowns that are introduced at a young age of 1" to 1.5" will work out well. Keep in mind, the more clowns you have translates into more "inches" of fish for your anemone. It is best to buy the anemone first and give it a few months to acclimate and grow before adding clowns. Not all clowns take to all H. crispa.

It has been found in nature hosting the following 14 Clownfish species:

• Clark's Clown fish Amphiprion clarkii
• Pink Skunk Clownfish A. perideraion
• Saddleback Clownfish A. polymnus
• True Percula Clownfish A. percula
• Three-Band Clownfish A. tricinctus
• Orange-fin Clownfish A. chrysopterus
• Barrier Reef Clownfish A. akindynos
• Two-Band Clownfish A. bicinctus
• Red Saddleback Clownfish A. ephippium
• Wide-Band Clownfish A. latezonatus
• White-Bonnet Clownfish A. leucokranos
• Red and Black Clownfish A. melanopus
• Oman Clownfish A. omanensis
• Orange Skunk Clownfish A. sandaracinos

• Venomous: Yes
• Temperament: Semi-aggressive
• Compatible with:
  • Same species - conspecifics: Sometimes
  • Anemones: Monitor
  • Mushroom Anemones - Corallimorphs: Monitor
  • Leather Corals: Monitor
  • Starfish: Monitor
  • Feather Dusters, Bristle Worms, Flatworms: Monitor
  • Nudibranch, Sea Slugs: Monitor

Sex: Sexual differences

No sexual difference in appearance is known.

Breeding / Reproduction

The H. crispa typically do not breed in captivity. Anemones in general can multiply by sexual and asexual means. One way is using fission, which is when they actually split in half from the foot or mouth to form a clone, although the clone is its own animal, similar to twins. They will also reproduce using male and female sex glands or find another anemone of the opposite sex. This results in the production of ciliated planula larvae. This planula will eventually fall to the sea floor, develop a pedal disk, and then begin to grow into a new anemone.

• Ease of Breeding: Difficult - The H. crispa typically do not breed in captivity.

Fish Diseases

Problems for the Sebae Anemone are pretty minimal unless your lighting, water movement, feeding, and water quality are low. Then your anemone will detach to look for "better conditions." In general, if your anemone moves, it is not happy. Some predators can be other anemones, nudibranchs, sea stars and some angelfish. Bristle worms also have been known to irritate and chew at H. crispa.

Availability

Buy A Sea Anemone: The Sebae Anemone or Leather Anemone H. crispa is easy to find in stores and online. The cost online starts at about $24.00 USD and goes up depending on size, color and species.

When selecting an anemone, be careful not to buy a bleached anemone or an artificially colored anemone. These conditions, especially bleaching, can be fatal as the anemone works to purge all the color and return to the color it was originally, usually a tan or reddish brown.


Click Here to buy your very own Sabae Anemone!
References

• Animal-World References: Marine and Reef
• Scott W. Michael , Damselfishes & Anemonefishes, TFH Publications, 2008
• Ronald L. Shimek, Guide to Marine Invertebrates: 500+ Essential-to-Know Aquarium Species, Microcosm, 2005
• Alf Jacob Nilsen and Svein A. Fossa, Reef Secrets: Starting Right, Selecting Fishes & Invertebrates, Advanced Biotope Techniques, T.F.H Publications inc., 2003
• Helmut Debelius and Hans A. Baensch, Marine Atlas Volume 1 (Baensch Marine Atlas), Microcosm Ltd, 1997
• Joyce D. Wilkerson, Clownfishes, TFH Publications, 1997
• Albert J Thiel, Heteractis Type Anemones, NetPets.org, Copyright 1995-2008
• Bob Goemans, Leathery/Sebae Anemone , Animal Library, Saltwatercorner.com

Great Video Found showing off these beautiful hosted pair!