Archive for June, 2008

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

Jun 30th

Posted by marinebioblog in Aquarium Equipment

2 comments

Light rail in use at That Fish Place

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
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Aquarium Equipment, Reef Aquariums

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

Jun 28th

Posted by marinebioblog in Aquarium Livestock

No comments

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.

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Aquarium Livestock, Aquariums and Fish in the News, Reef Aquariums, Saltwater Aquariums

Carnival fish part 2: The Betta

Jun 26th

Posted by marinebioblog in Aquarium Livestock

4 comments

Crowntail Betta

Hi everyone. Sorry for the lack of recent posts: we had some issues with the Blogger platform, but everything is ok now.
To view the first part of this article on Carnival Fish click here.
In part 1 of the Carnival fish blog, I discussed the care of goldfish, the most common fish that you are going to see at these spring time events. Part 2 will discuss another fish that you may come across as a prize or gift, The Betta.
The Betta fish, Betta splendens, is another commonly found “prize fish” that you may have the pleasure of become the new owners of. Bettas are one of the most beautiful freshwater fishes that are available in the aquarium hobby; their striking color and ornate finnage are quite remarkable.
Bettas are often chosen as prizes because of their ease of care, and ability to do well in very small amounts of water. The Betta is native to areas of Thailand, where they are exposed to times extreme rainfall and drought, which during times of drought can result in little more than a puddle to live in. Unlike most fish, the Betta does not solely rely on oxygen from the water it resides in, it has the ability to breathe air. Bettas are members of a group of fishes called Labyrinth fishes. Labyrinth fishes have a specialized breathing organ, called the labyrinth, which allows them to breathe air at the waters surface, somewhat like a primitive lung. The ability to breathe air allows the Betta to survive in very warm water with little or no dissolved oxygen. This is how Bettas are able to cope with very small fish bowls, and is often how they are displayed and sold.
PLEASE do not use this as an excuse to keep a Betta in extremely small environments for extended periods: although they can survive in only a few ounces of water, they will not be happy and comfortable.
Bettas can be kept in unfiltered bowls, provided adequate water changes are maintained (at least 20% per week), and water quality is monitored. Larger aquariums of at least several gallons are prefered, the bigger the better. There are a number of small desktop aquariums that are ideal for Betta keeping.
There is another side of the Betta fishes heritage that there is much controversy surrounding. Another common name for the Betta, is the fighting fish, or Siamese fighting fish. This name comes from the aggressive nature that these fish have towards one another, especially two males. The Thai name for these fish is”pla-kat”, which means biting and tearing fish. When placed in the same tank, two male Betta fish will literally fight to the death. There is a whole world of fighting and gambling involving the Betta in other cultures. Fighting Bettas is not considered an appropriate practice in the hobby.
There are many commercially produced Betta foods, in pellet, flake and freeze dried forms. A good varied diet is best. Feed only as much as the fish will eat in a few minutes, take extra care not to overfeed, especially in unfiltered bowls. Bettas prefer warm water, 72-78 degrees, so avoid cool areas like window sills, and hallways when possible. Direct sunlight should also be avoided; this will lead to unwanted algae growth, and temperature fluctuations during the day. While you can not keep bettas together, they can be kept in peaceful community tanks, with other types of fish.
If you have any futher questions about bettas or other carnival fish, post them and I’ll be sure to answer.
Until next time,
Dave
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Aquarium Livestock, Freshwater Aquariums