That Fish Blog – Aquarium Advice and Information

It has been a long-understood fact that the tranquility of aquariums has been known to help relieve stress and lower heartrate and blood pressure in some. As the biomedical field continues to grow and become more important to advancements in health care, the methods and options used by research also continue to expand. During this expansion, aquatic and marine organisms are becoming important in making advancements towards the health of all of us. Some of the fish and invertebrates you have in your home aquariums may someday help to save your life. Here are just a few of the organisms researchers have turned to:

Zebra Danio (Danio rerio): This fish is one of the most widely-used by researchers. They have become model organisms used for genetics research, neurological and other medical research, environmental studies and even organ and tissue regeneration. Specific genes have even been identified in different color pattern mutations. One of the most brightly-colored community aquarium fish, the popular Glo-fish, is a variation of the Zebra Danio that was original spliced with jellyfish DNA to create a fluorescent fish used to detect pollution and toxins. Zebra Danios are even on the very short list of animals that have made a trip into space!

Horseshoe Crab (Limulus polyphemus): The Horseshoe Crab is right next to the Zebra Danio in terms of the number of studies it participates in. They have compound eyes that have become important in vision research and a substance found in their blood known as Limulus amebocyte lysate (LAL) can help researchers detect bacteria and pathogens in medications and human tissue. LAL is collected in much the same way a person donates blood and the crabs can be released after collection. You can read all about them here.

Mussels: Mussels, the clam-like bivalves popular in aquariums and seafood restaurants alike, are already helping to heal wounds and have established their staying power in the medical field with their…well, staying power. Mussels used very thin filaments known as “byssal threads” to attach to hard surfaces. The adhesive that they use to attach themselves to surfaces is similar to the “Krazy Glue” and superglues that we all use to piece together broken mugs at home, but is much more effective in the salty, wet environments where the bivalves live. This adhesives is also extremely strong but still flexible. Researchers at companies like Johnson and Johnson have developed glues from the byssal thread compounds (warning: some graphic surgical images) that help to seal wounds and reattach bone fragments without the use of foreign materials like stitches and sutures.

Mantis Shrimp: This notorious group of invertebrates has earned a bad reputation in the aquarium industry as the secretive live rock hitchhikers known to pick off tankmates or even break aquarium glass, all while earning a following with a select few as an original showpiece. Among researchers, their powerful strikes and extremely complex eyes have made them the subject of many studies. The strike of a mantis shrimp is one of the most powerful and fastest strikes in relations to their size and researchers have studied their mechanics to discover how this power is possible. The eyes of the mantis shrimp can convert polarized light wavelengths and function over almost the entire light spectrum from infrared to ultraviolet, a feat our own eyes can’t even come close to. Their ability to convert and filter light across this spectrum has led researchers to look at mantis shrimp as the next step in optical devices like CD and DVD systems. While most of the research on mantis shrimp still seems to be focused on the “how’s”, it is only a matter of time before scientists discover how we can use what the mantis shrimp teach us.

Platies and Swordtails (Xiphophorus sp.): These two groups of livebearers are very popular, bright little community fish but recent research has given them a much more profound meaning. These livebearers are some of the first subjects to prove that some cancers like certain melanomas are actually hereditary and can be passed to offspring. Some of the dark pigment cells in these fish have been known to multiply out of control and form cancerous tumors. Remarkably, some of these fish can actually continue to live and thrive even with these tumors – and they can reproduce and pass this condition on to their young. While some forms like the popular Mickey Mouse Platies can form melanomas in the spots by their tails, it is more apparent in fish with a lot of black in their coloration. Scientists are working to understand how this condition is passed and how the fish can continue to live with it.

Corals: In addition to providing some color to the Zebra Danios already mentioned, some corals are giving biomedical scientists some inspiration in designing medications. Scientists have recently discovered capnellene, a compound found in a species of soft corals that can be used as a painkiller and may provide relief to those suffering from Multiple Sclerosis and other neurological conditions. Some of the same fluorescent proteins used to color Glo-fish are also being applied to some cancerous cells, allowing researchers to much more easily track their spread.

This is just a small sampling of how animals that have long been popular in the aquarium trade are being used to improve health and medications for all of us. As we as aquarists work to keep our own aquariums alive and healthy, those same fish and invertebrates may be working to save our lives as well.

Thanks for reading,

Eileen

Hello, Frank Indiviglio here.  Please see Part 1 and Part 2 of this article for general information on Damselfishes and their close cousins, the Clownfishes, and for notes on the care of the beautifully-colored Percula clownfish, Amphiprion percula.

Damselfishes in the Aquarium

Damselfishes are generally small, brilliantly-colored and in near constant motion.  These characteristics, along with their general hardiness, render them quite popular with aquarists.

Despite their small size, most damselfishes survive quite well in aquariums with larger fishes.  However, most are very territorial and rather aggressive towards their own and similar species (please see below).

Taxonomy

Together with the ever-popular clownfishes, the damselfishes are classified in the Family Pomacentridae, which contains over 325 species.  Many are superficially similar in appearance but differ greatly in habitat choice, food preferences and other regards, and ichthyologists (fish scientists) describe new species regularly.

Marine Gardeners

Damselfishes seem inordinately protective of their territories, so much so that these tiny warriors will even attempt to drive off human divers!  Research has revealed that several species engage in “aquatic farming, with mated pairs protecting beds of algae, a favored food.  Thick mats of algae often grow within well guarded territories but are absent outside these territories, due to a large number of other fishes and invertebrates that feed upon algae. 

The industrious little damselfishes have even been seen to “weed” their algae beds by removing debris and, possibly, competing algae species.

Further Reading

An interesting article on the relationship between Cocoa Damselfishes, human activities, coral reef health and algae is posted here.

I’ll discuss the care of various damselfish species in future articles. Until then, please write in with your questions and comments. 

Thanks, until next time,

 Frank Indiviglio

Pom-Pom Pulsing Xenia is one of my favorite corals. Quite simplistic, in color and shape, but there is something about the pulsing action and the beauty of the polyps that ranks it in my top ten corals. There are a few different types of pulsing Xenia found in the trade, such as the Pom Pom and the Silver varieties.

Considered a pest or a “weed” to some, others find it almost impossible to keep alive. There are plenty of possibilities as to why this is the case, but it always comes down to water quality. It is thought that Xenia cannot take in food like many corals do feeding on zooplankton and phytoplankton, leaving photosynthesis as the main food source. Xenia also has the ability to absorb certain nutrients and organics from the water column when needed. Due to the rate of growth and the ability to absorb organics, some people use Xenia in refugiums with or without macro algae to export excess nutrients. Not a proven miracle worker, but something to brighten up a refugium and do some work at the same time. Not to mention a small income possibility; since Xenia has a difficult time being shipped from supplier to store due to the amount of time being in a bag, the best supplier of Xenia is from local “coral farmers”.

Xeniids, despite their tolerance to not so clean water conditions are very sensitive to lower pH levels, especially when there is a constant fluctuation in levels. This can lead to a lack of pulsing, or even to the disappearance of the colony. Temperature, lack of or too much water flow, low lighting, and even over skimmed and over filtered aquarium can lead to problems.

The other potential problem with Xenia is it’s ability to take over the aquarium. With an obnoxious growth rate, neighboring corals can quickly become the next object that the Xenia grows on, possibly choking out the individual. In this situation, removing the Xenia becomes the major problem. Simply cutting the Xenia off the coral or rock may do the trick, but it has an uncanny ability to sprout a new colony or colonies from the original piece. A Kalk paste ( a paste of kalkwasser that can be applied to invasive Xenia polyps to kill those encroaching portions) can do the trick, but must be used with extreme caution with nearby corals or with pH levels. Again, to most people this is a good problem, thriving corals can equal profit.

So the next time you are looking for a hardy, unique coral, consider giving Pulsing Xenia a try, in the right application it can really shine.

Hi, Dave back again, just wanted to share with you some of the amazing Tridacna Clams that we have been seeing over the past few weeks. The diversity of colors and patterns that we have received in recent shipments may be the best that we have ever seen. That is saying something, given that I have seen thousands of clams over the years, but every time I walk past the clams lately, I cannot help myself from stopping to admire them for a while.

The photos shown here are just a sample of some of what we have had in stock, many were snatched up before we could even get pictures taken of them.  These clams have been coming from a number of sources, both captive raised and wild stock. We have gotten some really nice farm raised T. derasa and T. squamosa from ORA (oceans reefs and aquariums). The Derasa Clams in particular have had really nice color patterns.

We received some really amazing T. maxima clams that were wild harvested from Tuamota, a chain of island atolls in French Polynesia. We are expecting a new shipment of these Maxima Clams in the coming weeks, which we are eagerly awaiting. We only got a few of these specimens from the last batch that were imported, and were sorry we did not get more. These may have been the nicest Maxima Clams that I have ever seen.

We have started to see T. crocea clams become available again, they had become scarce earlier this year. Most of the Crocea Clams in the hobby are coming from Vietnam these days. These wild harvested clams have been coming in a nice variety of sizes and color morphs.

Check out our YOUR CHOICE section of our livestock page in the coming weeks for all of our WYSIWYG clams and animals, as we get some more of the beauties in stock and up for sale.

Hope that you enjoyed the photos of some of our clammy eye candy!

Dave

Hey folks, as promised, here’s the first installment of my favorite fish! Just remember everyone’s opinion differs and I would like to see other peoples faves,  too, so please leave a comment if you have an opinion.  Here goes, (in no particular order)!

Copadichromis azureus – This haplochromine is a zooplankton feeder. Males attain a length up to 8 inches with females around half that. A colorful fish, males sport a metallic blue with a white dorsal edge and black fins. Also sold as C. chrysonotus.  They are as attractive as they are interesting to watch.

Protomelas insignis – Also known as P. spilonotus (Tanzania) this particular hap attains a length of about 10 inches, with females at 7.  Males develop a bluish green head with 3/4 of the upper body dark blue while the bottom 1/4 is yellow. Beautiful!

Pseudotropheus polit – This feisty little cave brooder, which tops out at 4 inches, has a nasty napoleon complex. Males become a very light blue with a black face. This fish will keep you on your toes!

Aulonocara ethelwynae – This peacock attains a length of 5 inches, and has an understated beauty.  It is not a very colorful fish, as compared to other peacocks. The body is mostly brown with some yellow accents, and it has a blue lower jaw. The fins are their most attractive feature as both the anal and dorsal are blue to a light purple in color.  A fish that lives around the sandy areas of the lake,  it also needs rock for protection and breeding.

Dimidiochromis compressiceps – This piscivore (fish eater), which is also known as the Malawi Eye Biter, attains a length of 11 inches and is rarely encountered in the rocky habitat. It mostly frequents reed stands and vallisneria beds where its laterally compressed  body can allow it to hide as it stalks prey. Males develop a metallic blue face and body, a white dorsal edge with red tips, and a red anal fin with blue white egg spots.  What is not to love about this fish!

Nimbochromis livingstoni – This 11 inch piscivore has an intresting hunting behavior, and is a blast to watch in action. It partially buries itself in sand and feigns death. It has a mottled pattern of brown blotches on a pale body.  The pale color attracts smaller fish, which are then caught with a sideways thrust, like lightning! Dominant males develop gorgeous dark  blue coloration.

Tyrannochromis macrostoma –  Another predator, this species attains a length of 14 inches and has a peculiar hunting technique, also spectacular to observe. It hovers in a head-down vertical position and tilts its body to one side.  The position allows this hunter to observe its prey in the rock and snatch it out of its hideout.  Males are a blue with yellow-orange in the anal and pelvic fins.

Protomelas steveni (Taiwan Reef) – This awesome species hails from three different areas with differences in colors. Higga Reef variants are all blue with a red anal fin and a white blaze, Ngkuyo Reef variants have a blue head some blue in body, while the back and belly are both yellow, and the anal fin is yellow. Taiwan Reef is my favorite, featuring a blue face and back, yellow body, red anal fin and a white blaze. Simply gorgeous fish. There is also an albino version which is stunning.

Rhampochromis sp. – Open water predators, these “Malawi Barracudas” range in size from 10 inches to 18 inches. They are mostly silver, though a couple species also have yellow anal and pelvic fins. They’re made to chase down prey, natural hunters you can’t help but to admire.
Any Lethrinops sp. or Tramitichromis sp.- These sandy living species come in all “flavors” and I will always have a soft spot for them for the variety of color they exhibit and their unique and interesting behaviors. My favorite variants are the Tramitichromis ‘Red Flush’ and the Lethrinops ‘Auritus Lion’.

In closing, lets not forget that these are my faves I would love to hear from anyone who reads this blog about their favorite Malawi species and variants, please take a moment to give your take in our comments section and as always if you have any questions, let me know! Next up are my favorite Victorians!