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Contains articles featuring information, advice or answering questions regarding saltwater aquariums, livestock or equipment.

The Use of Light Rails and Moving Aquarium Lighting in Reef Aquariums

The use of light rails, or mechanical light moving devices, has been used for many years in the horticultural industry. Now this technology is available for the aquarium hobby. By moving your light source, you can maximize the potential of an individual light fixture, by covering far more area with maximum light output vs. a stationary light source. Light energy, commonly measured in lumens, dissipates with distance from the light source. The only way to increase coverage area of a fixed light source is to move it farther away from its target area. This may cover a greater area, but will reduce the light energy that reaches the target. The other solution is to use more light fixtures, with more cost, more heat, and increased operating expense. Another problem with stationary light sources are the shadows that are created in the illuminated area, which can create unnatural growth patterns. In nature, as we all know, the sun is not in a fixed position in the sky. Areas that are shaded during parts of the day, may receive light during other times. Using a light rail mimics this natural occurrence, by changing the angle at which the light reaches its target. Areas that may not get any light with a fixed position bulb, will get light when using a moving light source.
Aquariums that require high output lighting, typically metal halide lighting, pose some problems for aquarists. These lights are very expensive to purchase, create a great deal of heat, and are expensive to operate, and replace. Using a moving light source on your reef or live plant aquarium can help solve some of these problems, you can keep your light closer to the water surface, and maximize the light energy that reaches into the aquarium. Another benefit to using a moving light system is the number of light fixtures needed to cover a given area. A six foot long aquarium can be sufficiently covered by two moving metal halide light fixtures, where it would require at least three were they stationary. Less light fixtures means less heat, less operating cost, and fewer bulbs to replace annually and more natural growth patterns.
Using light rails are not going to be practical for all applications. Smaller tanks are not practical to use these systems on, and you need to have the space to install the equipment. Applications such as “in wall” aquariums that have all the equipment hidden from view, and especially large aquariums or coral propagation systems will be able to take better advantage of what the use of light rails has to offer.
Beyond the cost and functional benefits of a light rail system, they are just plain cool to watch. The moving light source over an aquarium creates an ever changing mix of shadows and colors in your aquarium as the angles of light change on the livestock and objects in the aquarium. A moving light system is definitely a gadget geeks kind of device.
Until next blog,
Dave

News and New Research on Seahorses and Seadragons (Family Syngnathidae)

Seahorses have much to attract aquarists – armor plated and prehensile tailed, and with independently-moving eyes and wing-like fins, they can also change color as well as grow and discard filamentous appendages. And, of course, the males become “pregnant”.

My first contact with seahorses came in the mid 1960’s when my grandfather, long in awe of these unusual fishes, mail-ordered a group of dwarf seahorses, Hippocampus zosterae, from a dealer in Florida. The shipment included several males carrying eggs, and I was hooked – so much so that I wound up writing a book on seahorses.

Texas A&M researchers are now learning the male seahorse’s pouch is far more than a mere container for eggs, and are trying to discover just how such a unique organ managed to evolve. Tissue from within the pouch actually grows around the eggs and functions in a similar manner to a mammalian placenta. Through it the seahorse father is able to keep blood flowing around the eggs, and to provide them with oxygen and nutrition. Amazingly, he also makes minute adjustments to the salinity of the water within his pouch, gradually increasing it as the embryos’ needs change. By hatching time, the salinity of the pouch water matches precisely the salinity of the surrounding ocean.

The male seahorse fertilizes the eggs once they have been deposited into his pouch by the female. From that point on, the reproductive roles of the sexes are reversed. The researchers at Texas A&M are also looking into the effect this has had on mate selection and other aspects of seahorse reproductive behavior. In certain species of pipefish (close relatives of the seahorses) females have the bright coloration usually associated with male fishes, and they compete for access to the egg-incubating males. Seahorses are, as far as we know, monogamous. They form long-term pair bonds which are reinforced, in many species, with daily “greeting” rituals (the pair clasps tails, swims together, etc.), but much about how role-reversal has affected mate selection is unknown.

In other related news, the Georgia Aquarium has announced that one of its male weedy seadragons is carrying eggs, only the third time such has been recorded in a US aquarium. Weedy seadragons, and the larger and even more flamboyantly decorated leafy seadragons, are close relatives of the seahorses and pipefishes and also exhibit similar reproductive strategies.

You can read more about the Georgia Aquarium’s seadragon breeding program and see a seadragon video at:
http://www.georgiaaquarium.org/exploreTheAquarium/webcam-seadragon.aspx.

Please also take a look at my seahorse book if you have a chance (see above) – I would greatly appreciate your feedback.

I’ll write more about keeping seahorses and their relatives in aquariums in the future. Until then, please forward your comments and questions.

Thanks, Frank.

Cold Water Aquariums

Oyster Toadfish

Please welcome back Frank Indiviglio for another article.

Today I’d like to introduce you to the maintenance of cold water aquariums, a fascinating but often overlooked branch of aquarium keeping focusing on marine and freshwater fishes and invertebrates from temperate regions.

Exotics Close to Home
Please don’t be misled into equating exotic and interesting creatures with “far-off, tropical places”. Shorelines, ponds, tidal pools and rivers throughout the world’s temperate regions (with the exception of extreme s. Florida, the entire USA is in the temperate zone) yield animals of unimaginable variety and interest. While it is true that many of the most spectacularly colored fishes are found in the warmer parts of the world (their bright colors likely help males and females of the same species recognize each other among the great diversity of similar species in the tropics), breeding males of many temperate fish species, i.e. the sunfishes, do rival those of their tropical counterparts.

Why keep Temperate Fishes and Invertebrates?
Animals from temperate areas offer many advantages to aquarists who live in the USA. Often, our normal seasonal rhythms of temperature and light fluctuation are sufficient to encourage such creatures to exhibit natural behaviors, and even to breed. Also, it is often easier for us to provide a wider range of foods and a more natural environment for them than we can for creatures from faraway places. In some cases, where legal, we may even be able to collect and keep native fishes and invertebrates.

Creating Natural Habitats
If you live near a body of water, try to observe firsthand the environments and habits of a variety of aquatic creatures. You might consider modeling your aquarium after a particular habitat — a tide pool, a weedy, fresh-water pond, or a river bed, for example. Take note of the local substrates, rocks and other natural items and purchase similar ones when setting up your tank prod (collecting natural substrates is risky, due to the possibility of mineral, pesticide or other chemical leaching).

Heat
Cold water aquariums are maintained in a similar fashion to tropical aquariums, but we must consider the effects of heat. Many animals from temperate regions are very sensitive to rising water temperatures and to the lower oxygen levels that accompany them. You may, therefore, need to install a chiller to moderate temperatures during the summertime.

Species to Consider
Some of the animals that I have maintained with success in cold water aquariums, and which I plan to cover in future additions to this article, include American eels, fifteen-spined sticklebacks, pygmy and other sunfishes, mantis shrimp, sea stars, Chinese sailfin suckers, weather fish, horseshoe crabs, blue claw crabs, bullheads and madtoms, white clouds, various snails, crayfish and shrimp, giant water bugs and other aquatic insects and many others.

I’ll now give a quick overview of two unusual animals – the oyster toadfish and the spider crab – which are easily maintained in unheated marine aquariums. I’ll cover their husbandry in detail in future articles.

Oyster Toadfish, Opansus tau
This unusual marine fish, ranging down the Eastern Seaboard from Maine to Cuba, seems to cross the line between fish and amphibian – its face even resembles that of a toad. In addition, toadfishes produce sounds audible above the water and certain Asian species can travel overland for considerable distances.

Oyster toadfishes will become quite tame in captivity, and, given a tank of 55 gallons or so, may well breed. Males are ferocious guardians of their eggs, and have been known to stay with nests that are exposed at low tide.

Oyster toadfishes have survived for 15 years in captivity, and will accept nearly any meat-based frozen or pelleted food as well as live shrimp, small fishes and worms. They learn to associate their owners with food, but will bite when handled, and the spines that can inflict painful wounds.

Atlantic Spider Crab, Libinia emarginata
Spider crabs, common yet fascinating if you take the time to know them, are members of a family which includes the Japanese spider crab. With legs spanning 8 feet, these giants awed me when first I observed a large group in a pubic aquarium in Osaka, Japan. American aquariums now exhibit them as well – trust me, they are well worth the trip.

The Atlantic spider crab is a valuable aquarium scavenger, and, using its tiny pointed claws to probe into nooks and crannies, misses little. Younger animals have the endearing habit of jamming algae and vegetation into the crevices of their shells, taking on the appearance of a “walking plant”. They will also nibble at this portable garden from time to time. I have found that they forgo this habit when they reach a carapace size of about 3 inches, although I have yet to discover why.

Spider crabs rarely bother tank-mates and readily consume fish flakes, pellets, blackworms, frozen food fish foods, algae and green leafy vegetables.

In the next installment of this article I’ll write about temperate, fresh water animals that are readily available in the pet trade. Until then, please write in with your questions and comments. Thanks. Until next time, Frank.

Information on the natural history of the oyster toadfish, along with a photo, is available at:
http://fishbase.mnhn.fr/Summary/SpeciesSummary.php?id=3069&lang=Portuguese

Thanks Frank
Until Next Time,
Dave

The Octopus – General Natural History Notes & Care of the Common Tropical Octopus, Octopus cyaneus, In Captivity

Please welcome back Frank Indiviglio with another excellent article.
With their sharp eyesight, inquisitive personalities and large brains, octopuses seem far removed from their relatives – the 100, 000 or so species of clams, scallops, slugs, snails and other creatures that make up the Phylum Mollusca (the Mollusks). Over 700 types of octopus, squid, cuttlefish and chambered nautilus are known, with odd deep sea forms being discovered each year.

Octopuses have much going for and against them as pets. They are, without a doubt, the most intelligent of the invertebrates, and often seem to rival much more “advanced” creatures in brain power. Able to distinguish and associate various shapes with a food reward, some have even learned to unscrew glass jars to obtain food. In one laboratory, cameras revealed that an octopus was leaving its aquarium each night to prey upon crabs held in a neighboring tank. Each morning, the octopus was found back in his own aquarium, having crossed several feet of dry shelf space in his nocturnal travels! One that I kept would, according to my grandmother, “watch her” as she prepared dinner (octopus see very well, and notice movement outside their aquariums). Unnerved by the thought of our pet witnessing the demise of his relatives, she would cover the aquarium with a towel on those days when she cooked octopus or squid for dinner!

Common Tropical OctopusOn the down side, however, all species studied are quite short-lived (2 years at most) – quite odd considering their complex lifestyles. Males generally expire right after mating, and females survive only long enough to see their eggs through hatching.

The species most often seen in the pet trade is the common tropical octopus, Octopus cyaneus (please note that there is a good deal of confusion as to the identification of this species). Growing to a maximum length of 12 inches, it does well if provided excellent water quality (manage it as you would a delicate reef fish) and a secure retreat in which to hide. Octopuses absolutely need to hide and are intolerant of disturbance (although once acclimated many will become quite bold at feeding time). It is also important to avoid suddenly putting on a light if the room in which the aquarium sits is dark. When disturbed, octopuses release a dark-colored ink (sepia), which can be toxic to the animal in close quarters.

Bear in mind that octopuses consume large amounts of food and produce copious waste products – good filtration, frequent water quality tests and water changes are vital if you are to keep them successfully. Give your octopus the largest aquarium possible (this will help with water quality and in reducing stress on the animal) and be sure the lid is weighed down or otherwise fastened. The common tropical octopus does well at temperatures of 76-78 F. As most species are nocturnal, you should equip the aquarium with a bulb designed for nighttime viewing so as to be able to observe your pet without disturbing it.

Most octopus favor crabs, shrimp, clams, scallops, mussels and other shellfish, but usually take fish as well. Seafood markets are useful sources of food for your pet – as we know little of their nutritional requirements, I suggest providing as much dietary variety as possible. The wide range of frozen marine foods now available will provide you with a great many options as well.

Other species sometimes offered for sale include the red or pygmy octopus, O. bocki, which is highly nocturnal, and the common octopus, O. vulgaris. As the common octopus occupies a range spanning the Mediterranean, the Sea of JapBlue-ringed Octopusan and the Eastern Atlantic, it is likely a fairly hardy creature. However, with a leg-span approaching 3 feet, it is too large for most home aquariums.

It is important to remember that all octopuses, even very small ones, can inflict painful bites with their sharp, parrot-like beaks, and that they can never be considered “tame” enough to handle. Most if not all produce venom in order to subdue their prey, and even venoms not shown to be dangerous to people can cause severe or even fatal reactions in particularly sensitive individuals. Amazingly, the tiny the blue-ringed octopus, Hapalochlaena maculosa, quite capable of killing a human with one bite, is sometimes offered for sale. Learn to recognize this species and avoid it at all costs.

Breeding octopuses in captivity is difficult, as is raising the young. Recent research at the Spanish Institute of Oceanography indicated that dietary factors, especially the absence of fatty acids such as DHA and EPA, are responsible for high mortalities among those that do hatch in aquariums. Enriched brine shrimp have been used with some success, but more variety is likely needed. I would experiment with various species of marine shrimp, worms, plankton and tiny marine creatures seined from eel grass beds and other marine habitats (check the legality of collecting before doing so).

Octopus husbandry is in need of much attention by serious hobbyists. These fascinating, complex creatures are impacted by habitat loss and collection for the food, bait and pet trade. Breeding them in captivity will certainly take pressure off wild populations and help in understanding what they need to survive in the wild.

Please write in with your own thoughts and questions. Thanks…until next time, Frank.

You can see photos of hatchling octopuses and read about a captive breeding effort at:http://www.bbc.co.uk/norfolk/your/a-z_norfolk/a-z_octopus.shtml

Species Profile: Pygmy Angels

Welcome back Mellisa Leiter, one of the Marine Biologist who works in our fish room here at TFP. Mellisa has written an article about one of the coolest little saltwater fish around, the Pygmy Angel. I hope you enjoy!

Pygmy Angelfish

Pygmy angelfish are fairly small, yet bright and colorful. They are generally not-specific feeders and usually accept most prepared food offered to them. They should be offered frozen foods like Mysis Shrimp, Formula 1, Formula 2, and Clams. They should also be offered flakes, pellets, and a regular supply of algae to round out their diet. Pygmy Angelfish typically do well in an established aquarium, 55 gallons or larger. Some acceptable tankmates include damsels, clownfish, tangs, gobies, blennies, and wrasses. As with their larger Angelfish cousins, careful consideration needs to be taken when attempting to keep more than one Pygmy Angel in the same tank. Two Pygmy Angels of the same species or very similar coloration should not be housed together, they will be very aggressive towards each other. If you want to attempt to keep two different species of Pygmy Angels together, your best bet is with species of different coloration. While there is no guarantee that these feisty little fish will coexist in your aquarium, you can increase your odds of them getting along in a few ways. First, the bigger the tank the better; 55 gal tank or larger. Second, make sure that there is plenty of live rock with lots of hiding places, this will allow the fish to establish their own territory. You can also reduce aggression by adding the fish at the same time, this way no territory has been established by older residents. Pygmy Angelfish are generally “reef safe” but may nip at the occasional polyp from time to time. I would not recommend Pygmy Angels for reef aquariums with Acropora, or other SPS corals for this reason. Their max size ranges from 3-6 inches for most species.
One of the most popular Pygmy angelfish would be the Coral Beauty (Cenropyge bispinosus). Their colors range from a deep purple to shades of orange. They stay fairly small (3-4”) and can be housed in tanks as small as 30 gallons. Coral Beauty’s are usually “reef safe” but may nip on polyps as well as the slime coat on other corals. The Coral Beauty is very hardy once acclimated into a well established tank with plenty of liverock.

 

Another hardy Pygmy angelfish that does well in an established tank is the Flame Angel (Centropyge loricula). Their colors are a vivid red with black lines. The amount of black varies. Flame Angelfish do not have different juvenile to adult coloration’s so be sure to pick the stripe pattern that you like since it won’t change. Flame Pygmy angelfish tend to be more peaceful than some of the other pygmy angelfish. Flame Pygmy Angelfish are usually “reef safe” but may eat polyps or clam mantles.

 

One of the smaller pygmy angelfish that is also hardy is the Cherub Pygmy Angelfish (Centropyge argi) . Cherub Pygmy angelfish is a purplish blue with a splash of orange around its face. They reach a max size of 2-3 inches. Cherub Pygmy angelfish may be shy any first, but don’t let their small size full you. These little angels have attitudes and will defend their home at all cost. They are generally “reef safe” but may pick at the occasional polyp.
One of the larger Pygmy angelfish would be the Keyhole Pygmy Angelfish (Centropyge tibicen). They can reach a max size between 7-8 inches. Keyhole Angelfish are not as colorful as many of the other angelfish. They are mostly dark blue to black with the lower portion of the anal fin bright yellow and an oval white area on both sides of their body. Keyhole Angelfish do not tend to ship as well as some of the other angelfish but once properly acclimated they are usually pretty hardy.
One of my favorite pygmy angel is the Lemonpeel Pygmy Angelfish (Centropyge flavissimus). They are bright yellow with blue trim around both eyes and gill covers. Lemonpeels are generally shy and need lots of places to hide to feel safe. Once acclimated they usually become more social. Lemonpeel angels are more likely than some of the other pygmy angelfish to pick at LPS corals and clam mantles.
One of the more aggressive pygmy angelfish is the Eibli Angelfish (Centropyge eibli). Eibli Angelfish have a silver gray body with orange stripes, black tail rimmed in blue, and a hint of orange around the eyes and belly. These angels adapt fairly well to aquarium life if given an established tank with lots of macroalgae to graze on. Eibli Angelfish are usually “reef safe” but may nip on the occasional polyp or clam mantle.
While there are many pygmy angelfish that do well in aquariums there are some species that are gorgeous but are a challenge for even the experienced aquarist. The Potter’s angelfish (Centropyge potteri) and Golden Angelfish (Centropyge aurantia) fall under this category. Potters angelfish are bright orange with blue gray scribbled lines and blue trim. Golden Angelfish are a burnt orange color with vertical yellow stripes. These angelfish tend to be very shy and reclusive and do not readily accept prepared food.
I hope you enjoyed Mellissa’s article.
Until next blog,
Dave