That Fish Blog – Aquarium Advice and Information

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!

On 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 Japan 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

In the interest of science, Dave asked me to post some biology/aquatics breakthroughs recently discovered here at That Fish Place. We hope that the information provided allows other aquarists and scientists to continue what we’ve started.
Thanks, Melissa

It all started with our recent shipment of Blue-Tipped Acropora, Acropora sp. For those readers not familiar with coral, this is one of the most easily recognizable, most beautiful corals in the aquatics trade. Unlike most corals in the trade, these were asexually reproduced and shipped here from a local coral greenhouse. Upon arrival, we began our normal quarantine process; placing the frags in an aquarium containing conditions identical to the display tank they would eventually inhabit. Remarkably, right from the beginning we started noticing differences in this batch…. click here to read the rest of the story and view pictures.

Most of you have probably heard of the Horse Whisperer, and some of you are familiar with the dog whisperer as well. How about the Coral Whisperer? While he may never get a movie made about him, or his own cable television show, Mitch Carl of the Henry Doorly Zoo in Omaha Nebraska is being recognized for his ability to successfully raise Elkhorn Corals in captivity. I came across an article posted on the Omaha World Review website dubbing Mitch Carl as “The Coral Whisperer” for his ability to raise corals from wild captured eggs and sperm, where many others have had less success.

As part of an international research project which is studying sexual coral reproduction (SECORE), Carl and the Henry Doorly Zoo were one of many facilities that took part in the ongoing project, and received wild harvested Elkhorn coral eggs and sperm to try and raise in captivity. According to the article, 500,000 embryos were collected and distributed, of those only 1,100 were still alive after 3 months; these were Mitch Carl’s corals. As techniques have improved in subsequent harvests, survival rates have dramatically increased since the initial collection. Last year Carl was able to keep 75% on his embryos alive, other facilities involved in the project were still unable to achieve more than a 50% success rate. This is where the legend of the Coral whisperer comes from.

This project is of significance because of the coral species at the heart of the project. Elkhorn Coral is vital to natural reef systems throughout the world. It is not only one of the skeleton building corals that build foundations of the world reefs. The heavily branching Elkhorn coral provides habitat for many fish and other animals, as well as providing shorelines with a barrier from storm and wave action. Some estimates put destruction of the worlds Elkhorn Coral, mostly from human related activities, as high as 90%, and Elkhorn Coral is now an endangered species.

Most coral farming is done using asexual reproduction or cloning, taking small pieces or “frags” from a parent colony and allowing it to grow. This process is repeated time after time, and results in many copies of the original. Coral Farming using this “fraging” method produces coral that is adapted to captive environments, and thrives in aquarium conditions. This process works well for corals that are intended for aquarium or zoo use; however it is not a good method of reproduction for coral that is for reintroduction to the wild. These corals have been in captivity for many generations, and have adapted for unnatural conditions. Asexual reproduction is slow, and there is also the risk of introducing unwanted elements back into natural habitats.

Researchers hope that a viable sexual reproduction strategy can be reached, this will allow for “wild” corals to be grown in captivity in huge numbers, then be reintroduced back to the reefs where the eggs and sperm were collected. The hope is that these corals can be grown in coastal regions, where the eggs were collected, so that conditions can be matched as closely as possible to where they will be “planted” on the reef. Successful sexual reproduction of corals would also be of great value to the aquarium trade, the more captive raised corals become available, the less impact the hobby will have on natural reefs, as well as potentially lowering cost with the ability to mass produce corals sexually.

I hope you enjoyed this story. You can get more inforation about the SECORE project at www.secore.org

Until next blog

Dave

This blog entry was inspired by another one of the interesting seminars that I attended during this years MACNA conference, a seminar by Author and Hobbyist Mike Paletta “Pharmaceuticals & Marine Aquaria”. Mike’s presentation was based upon medications and treatments that have origins in other disciplines that have found their way into use for the marine aquarium.

Some of the medications and treatments that Mike spoke about have been used in the aquarium trade for many years, such as Metronidazole and Erythromycin.
Metronidazole was developed for use in human and veterinary medicine, and is used to treat a wide range of bacterial and parasitical diseases. Metronidazole is available in the aquarium hobby from a number of manufacturers, as either a lone agent (like Thomas Lab’s Fish-Zole, Aquarium System’s Hex-Out, or Seachem’s Metronidazole), or as an ingredient in more broad spectrum medications (like API’s General Cure, Jungle Lab’s Hole-N-Head Guard and Parasite Clear) Paletta focused upon the use of Metronidazole as a method for removing intestinal parasites in newly acquired fish. Intestinal parasites are a common problem in wild caught fish. Fish are not usually fed very much as they are moved from collector, to holding station, to export, to your local store, in order to reduce waste and maintain water quality. During this time fish will start to eat feces of other fish that they are being held with, so if any of the wild fish have internal parasites, then they spread rapidly.
Feeding new fish with Metronidazole soaked foods during quarantine is the best way to rid your new fish of internal pests, and to prevent infecting the fish in your display. Jungle Labs Anti-Parasite Medicated Food and Blue Lagoon Anti-Parasite Marine Gel Food are commercially available food that is pre-treated with Metronidazole and well work well with fish that will eat these forms of food. For finicky eaters, soak the food of choice with medication prior to feeding. This works well with most food types, including fresh, frozen and prepared foods. Internal parasites may have no outward symptoms. Long term problems such a reduced growth and inability to gain weight with heavy feeding may be the only signs of infestation.
Erythromycin is an antibiotic that has been used for many years in many medical disciplines for the treatment of bacterial infections. Erythromycin has been used successfully for the treatment of bacterial infections in the aquarium trade as well, and is available from several sources ( like Mardel’s Maracyn and API’s E.M. Erythromycin)
Paletta talked about a less common use for Erythromycin (EM) is to aid in the combat of Slime algae in the marine aquarium, one which I have used successfully many times. Slime algae is a rapid growing, and potentially dangerous problem in the aquarium. Severe outbreaks can grow quickly and smother everything in your aquarium. Slime Algae is a simple life form, a bacterial algae complex, which thrives in high nutrient conditions like overfed, overstocked, or dirty aquariums. Small outbreaks should be taken care of by improving water quality, increasing water flow, and physical removal by siphoning. In severe cases the use of EM can be really helpful. EM will rapidly kill slime algae in the aquarium, and help get your aquarium free from the problem. EM is not a miracle cure for slime algae, if measures are not taken to improve water quality, then the slime will return. EM should only be used in conjunction with improved husbandry habits.

The portion of Mike’s presentation that I found most interesting was the somewhat experimental use of some Veterinary drugs to combat pests in the reef aquarium. With the proliferation of the reef aquarium hobby, and the abundance coral propagating hobbyists over the last several years, a number of previously obscure pests are becoming more and more common within the trade.

Red Bugs (Tegastes acroporanus) have become alarmingly common in the propagated coral industry. These barely visible little crustaceans can rapidly reproduce, and decimate many species of Acropora corals very quickly. Treatments have been developed using Interceptor (Milbemycin oxime), a prescription de-worming medication for dogs and cats, which you have to get from your veterinarian. Several different protocols have been developed for treatment with interceptor, if you do a web search on the topic you can find a treatment plan that best suits your situation. Before consulting with your veterinarian about obtaining Interceptor, it may be a good idea to print out some articles about this new alternative use of the drug. This is not a well known alternative use for the drug, and you may get some resistance if your Vet has not come accross other requests for this use in the past.

Another reef pest that is becoming more prevalent in the hobby is the Acropora Eating Flat Worm (AEFW). These nearly invisible, translucent, flatworms attack only Acropora species corals, and are very difficult to detect (other than dead acropora). A good method that Mike uses for detection is to use a turkey baster to shoot a jet of water in and around colonies that are suspected to have AEFW, if they are present, you will dislodge some of them and see tiny translucent discs fly off the coral. There are several commercially available flat worm treatments available to the hobby, such as Salifert’s Flat Worm Exit, and Tropic Marin’s Pro-Coral Cure.
Mike Paletta spoke about a relatively new treatment for AEFW that has been developed using Levamisol, a drug commonly used as a pig de-wormer that is available through farm supply stores, or your veterinarian. Again, several protocols have been developed for the use of Levamisol against AEFW, so do some research and choose a method that best suits your situation.

An interesting side story of Mike’s presentation was one of his natural approaches to limiting parasites in his display aquariums. He actually trains fish to eat parasites from coral. He accomplishes this while he is quarantining his fish for introduction into his aquarium. The fish he chooses are natural predators of the parasites, in this case I believe they were 6-line wrasses, which he trains to select for the parasites and actively hunt them. While in quarantine he introduces corals that he knows have flatworms, and frees the worms from the coral using a turkey baster, at the same time he limits the fishes other options for food, so that they are forced to eat the flatworms. After “training” the wrasses this way for several weeks the fish start to aggressively hunt out the flatworms for a meal. Once the fish have finished quarantine, they are introduced into the display aquarium and continue to actively hunt for parasites. Pretty neat trick!

Hope that you found this as interesting as I did, until next time

Dave