Part 2 of a Special Feature on the Harzards of Owning a Reef by Marc Chodos is concluded plus the usual features.

Editorial

Sorry that it has taken so long to get this issue out online, and yes I know it is not quite February but I have another one to put out shortly, so thought might make this a bonus month ;-) I actually had most of it written ready to go in early January, but I have be rather busy and it just seemed to keep on being put on the bottom of the pile of things to do. Over the next couple of months things will be a bit more slow here on OZ REEF. It is really coing to crunch time with my PhD, and I have some serious work to do. Then on top of that I have the stuff that I do with #reefs as well, and that takes up a far amount of time as well. Anyway, I will try to keep things ticking over a bit.

There is a predator on the prowl in OZ REEF! And it has a veracious appetite for soft corals. The problem is that I really have little idea what is doing it. So far a really extensive colony of Xenia, twice three other separate Xenia colonies, three times one Finger coral, once another Finger coral and repeatably a really nice Leather coral that is no longer in existance :-( One of the main suspects is a red crab that has been spotted on a couple of occassions in the rock work at night, but it has never been seen close to a coral at all. This could be due to the fact that it sneaks around at about 3am in the morning, at which time I am very rarely awake to have a look at what is going on. I really have no idea what to do, other than have a look in every now and then at night and try and spot something that could be doing the damage. Even if I do, then there is the problem of capturing it to get it out. Until then I will suspect plans of keeping soft corals, or attaining anymore.

The new aspirated pump skimmer arrangement is going a lot better than it was operating as an air stone driven skimmer. More foam is being produced, and the column is filled with more finer bubbles than before. I am very happy with the change. The only problem is that using the Sen 700G pump now has the system operating about 1^oC higher than perviously. This might make things a bit more interesting when Summer comes around next year again, but as it is at the moment things are fine. The temperature sits around the 28^oC mark most of the time, going up to 29^oC mark in the afternoon when both of the metal halides are on.

Bunsen, Flame Angel Centropyge loriculus, is doing just fantastic and settled in really very well. It started to feed on flake food about 1 week after moving in, and during that time did not eat much other than picking at the rock. Was not overly enthusiastic about it, but now has the whole deal down pat, Bunsen comes up the right end of the tank when I am about to place some flake food in the tank along with the other fish. Now really knows the drill of when I am about to feed, front of tank hood goes up, stand door creaks open, three taps on the glass, and in goes the food ;-) All the fish now hang almost as soon as the hood door opens, and the rest soon follow, at the upper right hand side of the tank. It took another two weeks after that before he started to eat the seafood mixture that I make up, if interested in the recipe see the DIY Plans section. One thing about the behaviour of Flame Angels that is very interesting is the fact that they continually swim around the reef structure browsing the rock for things to eat. He is constant swimming around within 5cm of the rock surface, pausing here and there for something to eat. Though this might not be so good, if he happens to get a taste for some coral or something like that. But that is the risk I have taken with adding a pygmy angel, and am willing to take that risk.

Hope you enjoy the final installment of the two part article written by Marc. This part is the scary bit, where you find out about the dangerous infections you can get from your tank ;-O It is not worth taking this point trivially either, some of these infections do not respond very well to treatment. So is it worth the risk? All it takes is a small investment in some full arm aquarium gloves.

And one last thing, let me know what you think about the format of the Resident of the Month, as it is what I may use to update and finally put back online the full Residents Directory.
Thats all for this month. Catch ya,
DBW

Welcome OZ REEF's New Residents

• 2 x Hydnophora exesa, Horn Coral. Will leave the details to the Resident of the Month section.

Resident of the Month

Dear Marther ReefKeeper

Dear Marther,

I just have a quick question about heaters. I have noticed that for a small tank a higher wattage per unit volume is recommended than for a large tank, why is this?

From,
Maris E. Heiter

Dear Maris,

As you get to small tanks you then require a higher wattage per volume heater than for a larger tank. The reason for this is that as you get to a smaller and smaller tank, then the surface area to volume ratio increases. Therefore the area to loose heat versus the volume to store heat increases, and you end up with heat being able to dissipate out into the room at a much faster relative rate than for a bigger volume tank. As a result, the rate of heat loss from the tank is larger for a given volume for a small tank versus a large tank.

For example, a 10 x 10 x 10 centimetre cube has a surface area (600 cm²) : volume (1,000 cm³) ratio of 6. If you then increase the side length by a factor of ten, to 100 x 100 x 100 cm, then the ratio drops to 0.6. Therefore, per unit volume, the small tank has the ability to loose 10 times as much heat during any time interval. The relationship is not quite that simple with rectangular tanks, but the principles are just the same.

From,
Marther ReefKeeper

Special Feature

The Hazards of Owning a Reef

by

.... continued from December 1998 Issue ....

Anaphylaxis

Anaphylaxis, an allergic reaction to the animal's venom, is a medical emergency. Anaphylaxis is a systemic immune response to a compound. It is independent of the compound's innate toxicity. Because it is dependent upon the immune system, an anaphylactic response requires prior exposure to the compound. Following this initial exposure, there will be no physically evident symptoms. One could consider this exposure as "priming" the immune system. Later contact, either the next time or several times down the road, will produce a systemic, life-threatening response in susceptible individuals within seconds to minutes of re-exposure. Again, this response is variable from person to person, and generally independent of the level of exposure. This reaction is characterized by vascular collapse and shock, with or without respiratory distress. Possible symptoms include:

• Upper airway swelling -- hoarseness and a "lump in the throat" feeling.
• Lower airway obstruction -- chest tightness.
• Wheezing, and shortness of breath.
• Cutaneus involvement -- intensely itchy, red, raised hives with pale centers and wandering borders, that can be local or spread over the entire body.
• Gastrointestinal symptoms -- nausea, vomiting, diarrhea, and cramping stomach pains.
• Vascular collapse -- blood pressure drop, rapid heart rate, and shock.

Anaphylaxis requires prompt medical treatment with epinephrine and other support measures. Anyone who has experienced a severe allergic reaction should avoid exposure to the precipitating compound. If this compound is a toxin produced by a reef inhabitant, the animal should be removed from the aquarium. At a minimum, epinephrine should be readily available for immediate use in case the individual is exposed to the compound again. Because anaphylaxis is immune regulated, each response will likely be more severe than any previous exposure.

Local Allergies

In addition to the severe anaphylactic reaction, minor local allergic responses can also be initiated. This contact dermatitis can be very similar to the hypersensitivity reaction of poison ivy. Often, it will be difficult to differentiate an allergic response from the response of a toxin or foreign body. Sponges of the genus Tedania (fire sponges) can produce this type of allergic reaction. Moreover, spicules from the sponge are irritating, though they can be removed by gently applying adhesive tape to the dried area and peeling the imbedded spicules off attached to the tape.

Inorganic compounds such as the salt used in tank water can be irritating and produce a type of dermatitis. The rash, or chronic eczema, is often located near the antecubital fossa (the part that is hidden when the elbow bends). This patch is usually dry, red, and itches. The lesion is often produced by rubbing the arm against dried salt deposits along the top of the tank during routine maintenance. The dried deposits disturb the epithelial integrity and produce a local irritation. This type of hobby-related injury will heal in several days once exposure is stopped. Hydrocortisone creams may alleviate some of the symptoms. This type of irritation can be prevented by wiping salt deposits off the top of the tank before introducing the extremity into water and exposure can be limited by wearing arm-length gloves. Moreover, carefully washing the arm with freshwater afterwards will remove any salts before they can dry or sufficiently irritate the skin.

Infection

Finally, the most important non-acute complication of marine trauma is infection. Tank inflicted or otherwise unrelated injuries or wounds can become infected with halophilic (salt-loving) bacteria from the aquarium, or with other bacteria from the environment. In a study in which animal wounds were inoculated with Hong Kong beach water, 318 bacterial strains were isolated. The predominant marine/estuarine species were of the genera Vibrio, Pseudomonas, and Aeromonas. The infection rate was highly correlated with fecal coliform counts, implying that aquarium water, which is relatively pure when compared to seawater from many recreational beaches, does not harbor virulent bacteria in the same densities. In another experiment, oral cultures from two captive moray eels at the Chicago Shedd Aquarium were taken. Isolated bacteria "included Vibrio fluviolis, V. damsela, V. vulnificus, Micrococcus species, and coagulase-negative Staphylococcus." In addition, Pseudomonas puterfaciens was also isolated from cultures of the tank water. Other species of Vibrio have been isolated from oral cultures of Leopard, Maco, and Great White sharks.

Therefore animal bites can directly inoculate numerous virulent bacterial species into the wound. In addition, many of the bacterial species found free in tank water and in the slime coating of fish cause infections in both aquatic creatures and humans. This includes Erysipelothrix rhusiopathiae and related species which can produce a red patch with vesicles and smaller papules. The borders are well demarcated and slightly raised. The bacteria enter through minor skin trauma and initially produce an itchy and painful purplish area following an incubation period of less than four days. The infection expands slowly, mostly towards the body proper. Untreated, the infection will resolve within several weeks. Rare cases of disseminated disease and endocarditis, an infection of the heart, have been reported. Though this disease has yet to be described as an aquarium-associated problem, it is relatively common in the fishing industry and is most likely transferred through dead fish. Moreover, human wounds are exposed to Staphylococcus and Streptococcus species that are ubiquitous on the skin. Finally, it has been reported that fish handlers and aquarists are at a higher risk for common warts caused by various types of human papilloma virus, though this has yet to be substantiated. In short, the likelihood for some type of infection at some point is high among hobbyists.

Vibrio sp.

Species from the Vibrio genus are the most common marine bacteria, accounting for over 31% of all colonies culturable from water samples. V. vulnificus is probably the most common Vibrio species isolated from human wounds. It is gram negative, highly motile, strongly oxidase-positive, and ferments glucose (other species of Vibrio ferment lactose). Virulence is associated with the presence of an acidic polysaccharide capsule that protects the bacteria from host defenses. Virulent strains also produce destructive enzymes including proteases, lipases, DNAses, chondroitin sulfatase, mucinase, and hyaluronidase; with all of these enzymes being capable of dissolving different tissue components. This bacterium rarely causes infections in healthy humans, yet it can cause devastating infections in individuals with certain illnesses or those who are immunologically compromised. V. vulnificus is found at peak levels in water temperatures of 21-23^oC, the temperature that some reef aquariums may be maintained at. Furthermore, the presence of V. vulnificus is unrelated to fecal coliform counts in two studies, and it grows best in clean water. Filter feeding organisms such as oysters can concentrate this bacteria in very high amounts. Hence, eating contaminated raw oysters can produce severe sepsis, a systemic infection of the blood, with a high mortality rate. But, most aquarists do not eat the fruits of their labor, so a more likely form of disease is via wound infection. This can rapidly progress to secondary sepsis and is associated with a 7-24% mortality rate, even with medical treatment.

V. vulnificus cutaneus infections are restrained to the extremities, even if they are secondary to a primary sepsis from ingestion of the bacteria. This is most likely a result of its preference for a temperature lower than that of central core areas of the body. The initial infection presents early with redness, swelling, and intense pain. It quickly overwhelms the local immune response, as evidenced by the plethora of bacteria on biopsy at the dermal/epidermal junction, but the general lack of inflammatory cells. The redness changes to a bronze discoloration and bacteria move into the lymphatics and surrounding tissue. The bacteria spreads rapidly, destroying tissue with their toxins and producing large areas of necrosis. The process can mimic gas gangrene, with vesicles and bullae (blisters) often present. The bacteria destroy skin, blood vessels, connective tissue, and muscle. Invasion of blood vessels can lead to secondary sepsis. This infection requires aggressive treatment with antibiotics and surgical debridement. Even with this therapy, it is often rapidly fatal.

Several factors place certain populations at a heightened risk for V. vulnificus infections. First, its virulence is associated with host iron availability. The bacteria produce proteins that can complex free iron and allow for growth. Normally in the body, a protein called transferrin binds iron tightly and greatly limits the availability of the free form. Chronic diseases that increase blood iron levels produce a more favorable environment in which the bacteria can grow. Some of these diseases include: hemolytic anemia, where red blood cells are lysed and iron from the hemoglobin is released; hemochromatosis, a genetic disease in which excess iron is stored in the body; and liver diseases such as hepatitis and alcohol-related liver damage, which destroy the liver and decrease the amount of transferrin synthesised. Other proteins, such as complement (the body's immediate defense against invasion), are not produced in adequate amounts in severe liver disease. Furthermore, ethanol increases stomach acid secretion, which increases iron absorption from the small intestine. This leads to a net increase in the amount of total iron present in the body. Second, disorders that compromise the immune system will give V. vulnificus an advantage and allow for infection. These diseases include HIV, cancer, diabetes (also a problem because peripheral nerve damage can allow a wound or infection to go unnoticed for days), and genetic immune disorders.

Mycobacterium sp.

A second "hobby-associated infection" is caused by the bacterium Mycobacterium marinum. Unlike Vibrio species, M. marinum infections are very insidious. For example, in a Thailand study of 44 reported cases over 20 years, the average known disease duration prior to presentation was 2.5 years (range 1 month to 10 years). In another study of 31 patients presenting at 33 Kaiser Permanente medical centers in Northern California over 7 years, the average known disease duration prior to presentation was 2 months (range 2 days to 3.5 years). In the Thailand study, 12 patients (66.7%) had hobbies or occupations associated with fish and water exposure. The second study reported 16 patients (52%) who had potential exposure through fish tanks. Hence, this disease is intimately connected to water contact and the aquarium hobby. This has lead to several names, including "swimming pool granuloma" and "fish tank granuloma."

M. marinum is a slow growing acid-fast bacterium that is closely related to M. tuberculosis, the causative agent of tuberculosis. Thus, a percentage of M. marinum infected individuals will also have a cross-reacting positive tuberculin skin test. Unlike most other mycobacteria, M. marinum grows best at 32^oC. Hence, even in extremely rare disseminated infections, lesions are predominantly on the cooler extremities. Normally, the bacteria enter through sites of minor trauma, with the site of infection often on the fingers, hands, or arms. Since the onset is insidious, the incubation period is not known and has been estimated to be 2-4 weeks. Most cases evolve into a single granuloma. Granulomas are lesions composed of special immune cells that form a wall around infected tissue. This is done because the immune system has trouble killing the bacteria. It tries to surround and contain the bacteria, so that they cannot spread beyond the immediate area. Also, the immune cells in a granuloma are activated and produce strong bactericidal agents, facilitating the containment and eradication process. Most frequently, the infected site is red with some swelling. Granulomas will appear as elevated papules or lumps. Sometimes the granulomas crust or ulcerate. Bacteria can spread along the lymphatic drainage system, producing multiple granulomas and lesions. This most often occurs 4-8 weeks following the formation of the primary lesion (range 5 days to 1.5 years). Unlike Vibrio and other more aggressive infections, M. marinum infections are painless.

Superficial infections respond to antibiotic therapy, and involution of the lesions usually begins within 2 weeks of the initiation of therapy. Treatment is often several months long, and the infected area will heal with a scar. Multiple drug therapy is recommended since the bacteria can develop resistance during the long treatment period. Deep infections can occur following more severe trauma, including bite wounds. This type of infection often requires a combination of surgery and antibiotics. Disseminated M. marinum infections have been reported rarely in immuno-compromised individuals. This infection will present with numerous small papules covering the head and extremities but sparing the trunk. Except for the distribution, this disease will resemble chicken pox. Bone and joint involvement will also occur in these extremely rare disseminated cases.

Infection Prevention

Several steps can be taken to limit or prevent infection and disease caused by bacteria from an aquarium. First, try to avoid allowing traumatized areas from coming in contact with aquarium water. If possible, use the other arm or wear a long latex glove. All cuts and scrapes should be immediately washed with soap following contact with aquarium water. Use topical antibiotics such as neosporin. Do not let bowls or containers that come in contact with aquarium water/inhabitants be used for eating or drinking purposes. Vibrio septicemia is caused when the bacteria enter the circulation from the gastrointestinal system. Theoretically, contamination of food could cause infection. Do not dump aquarium water in sinks or bathtubs. A case of disseminated M. marinum has been reported in an infant that occurred from bathing in the same bathtub used for tank water disposal. Additionally, use antibiotics in your aquariums with caution. Exposure to antibiotics will lead to selection of resistant strains of bacteria, especially when these medications are not used properly (which is usually the case). For example, most aquarium freshwater bacteria are resistant to tetracycline because of its misuse by aquarists. Because these bacteria can cause infection and severe illness in humans, it is dangerous to expose them to substandard antibiotic therapy and risk selecting resistant strains. Finally, look for warning signs -- pain, redness, tenderness, a wound that is getting worse instead of healing, and red streaks spreading centrally from the wound towards the body. These are indications of infection, with the last two indicating the definite need for medical intervention. In short, simple steps can largely prevent aquarium-related infections and diseases.

Conclusion

In conclusion, over the ages reef inhabitants have evolved exquisite devices to aid in hunting, protection, and to allow them to gain an advantage in their fierce and competitive world. To the human eye, these same designs are beautiful works of nature's art. Unfortunately, these same adaptations can cause the aquarist much aggravation if proper precautions are not taken to guard from accidental injury. But then, everything has a price, right? This article has attempted to provide the reader with a solid introduction into the "dark side" of tropical reefs, and it must be remember that it is by no means complete. Other, probably more immediate threats include many of the chemicals that are added to tanks, and the electricity that powers the artificial reef. When in doubt the aquarist should always search out more detailed information; it is the unknown threat that is always most dangerous. Yet, probably the single most important thing aquarists can do to avoid injury is to use common sense. With a solid background, proper planning, common sense, and a little luck, one can experience many years of trouble-free fish keeping. This is the case for most aquarists.

Special thanks to Tom Heo for taking the time to edit this article.

References

Brown CK; Shepherd SM. "Marine trauma, envenomations, and intoxications." Emergency Medicine Clinics of North America, 1992 May, 10(2): 385-408.

Edelstein H. "Mycobacterium marinum skin infections. Report of 31 cases and review of the literature." Archives of Internal Medicine, 1994 Jun 27, 154(12): 1359-64.

Edmonds, Carl. Dangerous marine animals of the indo-pacific region. Melbourne, Australia: Wedneil Publications, 1975.

Erickson T; Vanden Hoek TL; Kuritza A; Leiken JB. "The emergency management of moray eel bites." Annals of Emergency Medicine, 1992 Feb, 21(2): 212-6.

Halstead, Bruce W. A color atlas of dangerous marine animals. Boca Raton, Fla.: CRC Press, 1990.

Halstead, Bruce W. Dangerous marine animals that bite, sting, shock, and are non-edible. Centreville, Md.: Cornell Maritime Press, 1995.

Howard RJ; Bennett NT. "Infections caused by halophilic marine Vibrio bacteria." Annals of Surgery, 1993 May, 217(5): 525-31.

Howard RJ; Burgess GH. "Surgical hazards posed by marine and freshwater animals in Florida." American Journal of Surgery, 1993 Nov, 166(5): 563-7.

Iredell J; Whitby M; Blacklock Z. "Mycobacterium marinum infection: epidemiology and presentation in Queensland 1971-1990." Medical Journal of Australia, 1992 Nov 2, 157(9): 596-8.

Isselbacher, Kurt J; Braunwald, Eugene; Wilson, Jean D; Martin, Joseph B; Fauci, Anthony S; Kasper, Dennis L. Eds. Harrison's principles of internal medicine. New York, NY: McGraw-Hill, Inc., 1994.

Kueh CS; Kutarski P; Brunton M. "Contaminated marine wounds--the risk of acquiring acute bacterial infection from marine recreational beaches." Journal of Applied Bacteriology, 1992 Nov, 73(5): 412-20.

Kullavanijaya P; Sirimachan S; Bhuddhavudhikrai P. "Mycobacterium marinum cutaneus infections acquired from occupations and hobbies." International Journal of Dermatology, 1993 Jul, 32(7): 504-7.

Laughlin TJ; Lavery LA. "Lower extremity manifestations of Vibrio vulnificus infection." Journal of Foot and Ankle Surgery, 1995 Jul-Aug, 34(4): 354-7.

Parent LJ; Salam MM; Appelbaum PC; Dossett JH. "Disseminated Mycobacterium marinum infection and bacteremia in a child with severe combined immunodeficiency." Clinical Infectious Diseases, 1995 Nov, 21(5): 1325-7.

Penman AD; Lanier DC Jr; Avara WT 3rd; Canant KE; DeGroote JW; Brackin BT; Currier MM; Hotchkiss RL. "Vibrio vulnificus wound infections from the Mississippi Gulf coastal waters: June to August 1993." Southern Medical Journal, 1995 May, 88(5): 531-33.

Tong D. "Coral Dermatitis in the aquarium industry." Contact Dermatitis, 1995 September, 33(3): 207-8.

Tong D. "Warts in aquarium industry workers." Contact Dermatitis, 1995 November, 33(5): 348-9.

Tong D. "Salt dermatitis in the aquarium industry." Contact Dermatitis, 1996 January, 34(1): 59-60.

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You Wouldn't Believe It!

.... there are four different oxygen carrying pigments in the Animal Kingdom. Hemocyanin, a copper containing protein, is carried in solution and is utilised by some mollusks and arthropods. Hemerythrin, an iron containing protein, is always found in cells and used by Polychaetes and Sipunculids. Chlorocruorin, an iron-porphyrin protein, is carried in solution and used by a limited number of Polychaetes. And finally Hemoglobin, and iron-porphyrin protein, is the most extensively found pigment and can be found in solution or in cells. It is used by most Vertebrates, Echinderms, Mollucks, Arthropods, Annelids, Nematodes, Flatworms, Protozoa and Plants.

.... blue-green algae or cyanbacteria can be any colour, including purple, red, black and frequently blue-green. They are typcially present in marine aquariums, though normally not obvious until a bloom occurs. Cyanobacteria is considered to be more closely related to bacteria rather than algae, but undertake photosynthesis and contain photosynthetic pigments very similar to red algae.

Bereavement Notices

2 x Xenia sp.
A casualty of some soft coral predator. The other was very small, and did not sufficiently glue it down when placed on a rock fragment. Floated away somewhere in the tank. Hoping that will find it somewhere on the rocks, but don't think this is likely. Could end up over the overflow, stuck on the pump inlets, or buried under the sand.

Clam
Filter feeding clam. Been going OK, but obviously not getting enough food, have to make sure I feed more yeast more often now I think, go to every second day with about 1/2 teaspoon.

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